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Gunnarsson, Klara. "Klosslådan Aniara : en komprimerad rymd." Thesis, Konstfack, Grafisk Design & Illustration, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:konstfack:diva-4744.
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Järleblad, Henrik. "Att lösapartiella differentialekvationermed FFT i fri rymd." Thesis, KTH, Skolan för teknikvetenskap (SCI), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-210860.
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Detta kandidatexamensarbete har till syfte att belysa och utforska hur partiella differentialekvationer kan lösas på ett enkelt, effektivt och noggrant sätt i fri rymd, dvs då området är obegränsat (Rn). Lösningsmetoder som fungerar bra på begränsade domäner är generellt inte speciellt effektiva för dessa typer av problem, då artificiella randvillkor måste sättas, och beräkningsdomänen måste göras stor för att få en god noggrannhet i lösningen. Arbetet baseras på en artikel av Vico et al. som publicerades i juli 2016 och som introducerar en metod baserad på trunkerade Greens-funktioner och snabba Fouriertransformen (FFT). Den har spektral konvergens, och är relativt enkel att implementera. Jämfört med periodiska problem, för vilka FFT-baserade metoder är optimala, så måste man för samma spatiella upplösning öka gridstorleken för transformen med en översamplingsfaktor i varje rumsdimension. Metoden har komplexitet O(N log N) där N är antalet gridpunkter. För att påvisa denna metods användningspotential så visar detta projekt hur metoden kan användas för att lösa både Poissons och Helmholtz ekvationer i två respektive tre dimensioner, och demonstrerar också metodens spektrala noggrannhet och förväntade beräkningskomplexitet.
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Svensson, Davoust Martin. "Automatisk generering av navigationsdata i en 3D-rymd." Thesis, Linnéuniversitetet, Institutionen för datavetenskap, fysik och matematik, DFM, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-12962.
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Datorspel genomgår en konstant utveckling mot mer komplexitet och i takt med att de virtuella spelvärldarna växer behövs mer och mer effektiva metoder att navigera genom dessa. I denna rapport undersöks möjligheten att automatiskt generera navigationsinformation och ett förslag presenteras på hur en algoritm för detta skulle kunna se ut.
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Ghawi, Christina, and Ariel Abedali. "Spektralmetoder för linjära elliptiska partiella differentialekvationer i fri rymd." Thesis, KTH, Skolan för teknikvetenskap (SCI), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-254796.
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Syftet med den här studien är att lösa linjära elliptiska partiella differentialek- vationer i fri rymd och att uppnå spektralkonvergenta numeriska lösningar, för glatta och kompakt stödda inhomogeniteter i två och tre dimensioner. Detta utförs genom att använda teori om Greenfunktioner och göra en om- skrivning av differentialoperatorns Greenfunktion i fri rymd till en trunkerad spektralrepresentation, genom att nyttja inhomogenitetens kompakta stöd; därefter, genom att använda resultat från Fourieranalysen och egenskaper av faltning, beräknas lösningen med hjälp av en snabb Fouriertransform. Trots att partiella differentialekvationer ofta kräver icke-triviala lösningsmetoder, resulterar detta kraftfulla tillvägagångssätt i ett simpelt och snabbt sätt att uppnå spektralkonvergenta numeriska lösningar.The purpose of this study is to solve linear elliptic partial differential equa- tions in free space and to achieve spectrally accurate numerical solutions, for smooth and compactly supported inhomogeneities in two and three dimen- sions. This is made by using results from theory of Green’s functions and rewriting the differential operator’s free space Green’s function to a trun- cated spectral representation, by utilizing the inhomogeneity’s compact sup- port; then, using results from Fourier analysis and properties of convolution, calculations are performed using a fast Fourier transform. Although partial differential equations often require non trivial solution methods, this pow- erful approach results in a simple and fast way of achieving highly accurate numerical solutions.
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Nilsson, Elaine. "Älskade Mörker : Död, rymd och hyperobjekt i Romantisk poesi." Thesis, Mittuniversitetet, Institutionen för humaniora och samhällsvetenskap, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-43183.
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I min uppsats kommer jag att diskutera döden och rymden som hyperobjekt och hur vi kan se på romantisk poesi ur ett ekokritiskt perspektiv idag med hjälp av dessa tolkningar. Genom att sätta poesin i kontext till tiden som den skrevs under vill jag markera var diskussionen om döden och rymden började och analysera de romantiska poeternas verk genom Timothy Mortons ekokritiska teorier om hyperobjekt. Människans ansvar till naturen från den enskilde individen till stora industrier är en del av vår samtidsdialog, en global dialog och jag tolkar de så att de romantiska poeterna, i sitt avståndstagande från den industrialiserade världens livsförhållanden, format delar av den här nya dialogen. Romantikernas koppling till naturen är rotad i deras fascination för mystik och det ockulta. Deras tid var en då man fortfarande kunde välja att ta avstånd ifrån den stundande industrialismen. W.B. Yeats, den sista romantiska poeten omringades av industrien och de nya samhällsstrukturerna, han flydde från rigiditet i religion och politik både spirituellt och fysiskt. Yeats liv förkroppsligar den romantiska poetens sökande efter frihet och därför är han också central i min uppsats. Vi kan förändra hur vi läser och uppfattar romantisk poesi i modern tid genom att se på döden och rymden som hyperobjekt.Godkänt datum 2021-08-25
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Janelm, Erik. "Tro i en obönhörlig rymd : Livshållningen i Pär Lagerkvists Pilgrim på havet." Thesis, Örebro universitet, Akademin för humaniora, utbildning och samhällsvetenskap, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-11002.
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Chen, Emily. "Thermal Loads in Space Turbines." Thesis, Luleå tekniska universitet, Rymdteknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-75719.
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Prediction of thermal loads within cavities in space turbine, has as been a challenging task in aspects of achieving accurate and reasonable estimations that are crucial for design concepts. The difficulty lies within the turbulent flow and its thermal interaction with the structure inside such section. It does not exist a method that works perfectly for prediction of thermal loads in any cavity and the taken approach to perform this kind of analysis has been differently chosen. The objectives of this work have been to improve methods for assessment of thermal loads in space turbines, especially calculation of the heat transfer coefficient and bulk temperature. As the thesis was conducted at GKN Aerospace Sweden, Trollhättan, one of theirs demonstrator turbine was chosen for the study case. Its first stage rotor blade and the nearby cavity were the main research regions. The flow can enter and exit the cavity through one slot and is characterized with a very low axial speed. For the studied regions, the wall surface has been subdivided into a number of segments. With prescribed wall temperatures and use of computational fluid dynamics (CFD) to compute the wall heat flux at the sections, the heat transfer coefficient and bulk temperatures were determined in three different ways. One of them was based on evaluating one single CFD result and derive the thermal loads from formulas. The others used by point-plotting approach, whereas one of them focused on formulating a model that describes the thermal interaction between the section walls. The results demonstrate that this model was able to predict a section's wall heat flux as a function of the wall temperatures in fair agreement with CFD results for a range of temperature variations. Further more, some of the predicted heat transfer coefficient at a section shows to be highly sensitive to the prescribed wall temperatures in the cavity and rotor blade.
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Huzelius, Alicia, and Hanna Kindberg. "Conceptual Design and Analysis of an Unmanned Autonomous Expendable Air Vehicle." Thesis, KTH, Flygdynamik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-244829.
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This project have looked into the possibility to develop a small autonomous expendable air vehicle to be used with other air vehicles to fly in a group or a swarm. The requirements of this project was that the air vehicle should be able to carry a payload of 8 kg, have arange of 100 km and fly at an subsonic speed at an altitude between 0 to 3000 meter. The air vehicle should also be launched from ground and be able to be stored for 3 to 5 years. The engine was predetermined to be a HAWK 240R. The method of designing the air vehicle asdescribed by Daniel P. Raymer in his book Aircraft design: A Conceptual Approach has been used with adaptation to this project’s specifications. A comparative air vehicle study has also been made. The focus for this project has been the air vehicle design, but launch method,manufacturing and cost estimation have been investigated.The result of this thesis project is the concept of an air vehicle that weights around 30 kg with optimal cruise condition, for maximum range, at sea level altitude and at Mach 0.2. But it was decided that the ability to reach the required range faster was more important than tofly as long as possible and thus Mach 0.6 was chosen for the same altitude. A suggestion to a ground launch device has been made. The manufacturing method for the larger part of the air vehicle was chosen to be 3D printed and an estimated cost analysis for the structure andthe components has been made.The conclusion of the project is that it should be possible to design a relative small vehicle, that is intended to fly together with other vehicles, for a reasonable cost. But before this idea can be realized, more research and testing must be done.Det här projektet har sett över möjligheten att utveckla en liten obemannad flygfarkost av engångstyp. Tanken är att flera flygfarkoster ska flyga tillsammans i en svärm. Kraven för detta projekt är att flygfarkosten ska kunna bära en last på 8 kg, flyga en sträcka på100 km, hålla en subsonisk hastighet på höjderna 0 till 3000 meter. Motorn var förbestämd till en HAWK 240R. Metoden för att designa flygfarkosten är beskriven i boken Aircraft design: A Conceptual Approach av Daniel P. Raymer och har anpassats till projektet. Enjämförelsestudie med liknade flygfarkoster har även gjorts. Fokuset på detta projekt har varit flygfarkostens design men även uppskjutningsmetod, tillverkning och kostestimering har undersökts.Resultatet för detta projekt är ett koncept på en flygfarkost med vikten på strax under 30 kg. Det optimala flygförhållandet för marschfart, för maximal flygsträcka, är att flyga Mach 0.2 vid havsytan. Men det blev beslutat att flyga den bestämda sträckan så fort som möjligtvar viktigare än att flyga så lång som möjligt och därför valdes marschfarten Mach 0.6 för samma höjd. Ett förslag på en uppskjutningsmetod har gjorts. Tillverkningsmetoden för flera delar av flygfarkosten bestämdes till 3D printing och en kostnadsestimation för strukturen ochingående komponenter har gjorts.Slutsatsen för detta projekt är att det är möjligt att designa ett relativt liten farkost, med tanke att flyga i grupp, till en rimlig kostnad. Men för att detta koncept ska kunna förverkligas måste fler undersökningar och tester göras.
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Guiho, Audren. "Design, development and use of a mechanism simulator for aeronautical engineering." Thesis, KTH, Flygdynamik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-244830.
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This paper deals with the strategy for developing a very specific mechanism simulator. This mechanism is currently designed by Safran Group. A previous version of the same mechanism does exist but the scale is not on a like-for-like basis. Therefore, physical phenomena involved in this mechanism and their magnitude are not comparable to the previous version of the mechanism and this is why a new simulator has been developed (specified, coded and validated) from scratch. The paper addresses the strategy adopted for modelling a mechanism laying on a wide set of parameters as well as its use.Artikeln handlar om en strategi som mål bestå av att utveckla en särskild simulator mekanism, för närvarande utformad av Safran Group. Det finns en tidigare version av samma mekanismen men systemskalor är inte i en like-for-like grund. Alltså, fysiska fenomenen som innebärs i mekanismen och deras magnitud kan inte jämföras med tidigare versionen av systemet. Det är varför en ny simulator har skrivits i kod. Artikeln analyserar strategin som adopterades för att utforma ett system som lägger på en bred uppsättning parametrar.
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Rubin, Felix. "Modelling & Analysis of a TiltWing Aircraft." Thesis, KTH, Flygdynamik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-244832.
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The aim of this report is the investigation of a hybrid vertical take-off and landing (VTOL) tilt wing aircraft which is in development at the company Dufour Aerospace. Using a model, programmed in MATLAB® different stages of flight can be simulated and investigated. Maininvestigation area of this report is the transition between cruise and hover conditions of the aircraft.The simulation is based on the six-degree-of-freedom nonlinear equations of motion for aircraft modified for tilt wing operation. The model characteristics have been determined using various CFD programs, wind tunnel data, as well as numerical and handbook methods.The main focus of modeling lies on the static longitudinal aerodynamic coefficients, the propeller and engine coefficients as well as a propeller slipstream model. Furthermore lateral directional aerodynamic coefficients and dynamic effects and a tail blower (Notar) system are modeled.As results, aerodynamic characteristics of the wing in the propeller slipstream are shown and discussed and the transition conditions are investigated by ’trimming’ the model at equilibrium points over its speed range and analyzing the resulting power requirements.
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Paskeviciute, Agne. "Preliminary Lander CubeSat Design for Small Asteroid Detumbling Mission." Thesis, KTH, Rymdteknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-248427.
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Asteroid mining is expected to become reality in the near future. The first step is to redirect an asteroid to a stable Earth orbit so that mining technologies can be demonstrated. Detumbling of the asteroid is one of the important steps in asteroid redirection missions. In this thesis, a preliminary lander CubeSat design is suggested for a small asteroid detumbling mission. The candidate asteroid for the detumbling mission is chosen to be 2014 UR, an Arjunatype asteroid with an estimated diameter ranging from 10.6 to 21.2 m. Due to the small size of the asteroid, the landing must be performed with an active control method after which the spacecraft must be firmly anchored to the asteroid. By using the multi-criteria decision making method PROMETHEE, the microspine gripper is chosen as the most suitable anchoring mechanism. Three main mission drivers are identified during the design process: data-flow between the lander and the mothership, Delta-V budget and pointing accuracy. The Delta-V required for landing on the asteroid and despinning it is estimated to be 10 m/s and 0.15 m/s at most, respectively. The uncertainty with the despinning Delta-V is due to varying estimates of the size of the asteroid. The required minimum pointing accuracy is estimated to be 6 degrees. The preliminary lander CubeSat design can be largely realised with commercial off-the-shelf components suggested in this work. Only some of the components have to be custom built or the technologies further developed. It is shown that a CubeSat lander is not able to detumble an asteroid that is rotating fast around multiple axes. However, if the considered asteroid is rotating around a single axis with a rotational period of 2.4 hours, it is be possible to despin it by spending just 1.5 kg of propellant. The suggested lander is a 12U CubeSat with an overall mass of 15 kg and power consumption of 65 W.Gruvdrift på asteroider förväntas att bli verklighet inom en snar framtid. Det första steget är att omdirigera en asteroid till en stabil omloppsbana runt jorden så att gruvteknik kan demonstreras. Bromsning av asteroidens tumlande är en av de viktigaste stegen i ett rymduppdrag där en asteroid ska omdirigeras. I detta examensarbete föreslås en preliminär asteroidlandare baserad på CubeSat-teknik för ett rymduppdrag där en asteroid ska omdirigeras. En asteroid av Arjuna-typ, 2014 UR, med en diameter på mellan 10.6 och 21.2 m är vald som kandidat för rymduppdraget. På grund av att asteroidens är relativt liten till storlek måste landningen utföras med en aktiv reglermetod och rymdfarkosten måste förankras till asteroiden. Med hjälp av en beslutsmetod utifrån flera mål, PROMETHEE, identifierades förankringsmetoden “mikro-ryggrads-gripare” som den mest lämpliga. Tre huvuduppgifter för rymduppdraget identifierades under designprocessen: dataflöde mellan landaren och moderfarkosten, Delta-V-budgeten och peknoggrannheten. Delta-V som krävs för landning på asteroiden uppskattas att vara högst 10 m/s. Bromsningen av tumlandet kostar högst 15 m/s. Osäkerheten med Delta-V för bromsning av tumlandet beror på olika uppskattningar av asteroidens storlek. Den nödvändiga minsta peknoggrannheten uppskattades vara 6 grader. Utformningen av landaren, baserad på CubeSat-teknik, använder till största delen komponenter som finns på hyllan, s.k. commercial-off-the-shelf. Det visas att en CubeSat-landare inte kan bromsa tumlandet för en asteroid som roterar snabbt kring flera axlar. Om den valda asteroiden roterar runt en axel med en rotationsperiod på 2.4 timmar, är det möjligt att bromsa tumlandet med endast 1.5 kg drivmedel. Den föreslagna landaren är en 12U CubeSat med en total massa på 15 kg och strömförbrukning på 65 W.
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Díaz, Martínez Sergio David. "Design of a variable focal length optics for a SWIR Earth observation camera." Thesis, Luleå tekniska universitet, Rymdteknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-83198.
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This thesis consists of a preliminary design study of a variable focal length optics for a SWIREarth observation camera which is planned to be placed inside a 6U Cubesat. After thesuccess of DRAGO instrument consisting on a SWIR camera onboard a Cubesat, which hasbeen recently launched (January 2021), the Institute of Astrophysics of the Canary Islands(IAC) began this project with the intention of adding zoom optics to SWIR space imagingsystems. This improvement will add versatility and it will allow changes in the effective fieldof view of the camera, hence achieving a certain magnification to study in more depth anyregion of interest.The main objective of this project is to provide a design solution for the presented challenge,where a mechanism has to displace different groups of lenses following their motion profilesin order to get the desired zoom. During this process different design options were evaluated.The chosen one consist of a ball screw mechanism where the rotation of the screw translatesinto linear displacement of the groups of lenses.The thesis presents a selection of commercial components constituting the mechanism, asone of the objectives of the project was to build a prototype of the mechanism. A structuralanalysis of the structure is done by using ANSYS simulations to ensure the viability of thedesign.
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Chivite, Sierra Javier. "Multiple fly-by for interplanetary missions." Thesis, Luleå tekniska universitet, Rymdteknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-83270.
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Current state-of-the-art of propulsion system for space vehicles does not allow to deliver therequired payload for the mission to all bodies in the Solar System. Therefore, alternatives havebeen developed to reach those bodies without having the necessary technology. Gravity AssistManoeuvres take advantage of the encounter of the spacecraft with one or more celestial bodies tomodify the velocity vector of the spacecraft. These manoeuvres have already been used previouslyto reach high v targets with a very low propellant consumption.This thesis models a Gravity Assist Manoeuvre to later apply the model to a space mission to reacha target with multiple gravity assist manoeuvres around the Moon to reduce the fuel consumption.In the first part, the gravity assist manoeuvre is designed based on the angle that the normal vectorof the plane of the fly-by forms with the perpendicular vector to the velocity of the spacecraft onthe Moon reference frame and the velocity of the Moon. The second designed parameter for thefly-by is the angle that the velocity of the spacecraft relative to the Moon rotates about the planeof the fly-by modifying the direction of the spacecraft’s velocity.The second part of the project applies the previous concept of gravity assist manoeuvres to aspace mission. A spacecraft orbiting on a Geostationary Transfer Orbit is injected into an orbitto the Moon. Once the spacecraft reaches the Moon, it flies by the Moon modifying the directionand magnitude of the velocity of the spacecraft in the Earth reference frame. The orbit obtainedafter the fly-by is then propagated for a given period of time before injecting the spacecraft againinto an orbit to the Moon. After arrival to the Moon, the direction and magnitude of the velocityof the spacecraft in the Earth reference frame is modified through a second fly-by. Afterwards,the previous process is repeated again for a third fly-by before transforming the velocity of thespacecraft into the Heliocentric reference frame. The orbit is propagated for a period of timebefore getting injected into an orbit to the target of the mission.The third part of the project aims to optimise the mission developed in the second part, thoughonly two fly-bys will be considered in this part to simplify the optimisation process. The previousmission has been developed in several sections and the minimum fuel consumption has beendetermined individually for each section, obtaining a local minimum. Unfortunately, the globalminimum fuel consumption determined as the addition of those local minimum fuel consumptionmight be different, i.e. different sections might influence other sections leading to a lower globalminimum fuel consumption that has not been considered before.The fourth and last part shows future work that might be done to the project. It includes themodification and application of the code for the optimisation, the study of powered fly-bys tomodify the previous parts, and the addition of perturbations and space interactions to develop amore realistic mission.
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Fatemi, Shahab. "Modeling the Lunar plasma wake." Licentiate thesis, Luleå tekniska universitet, Rymdteknik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-17543.
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This thesis discusses the solar wind interaction with the Moon and the formation of the lunar plasma wake from a kinetic perspective. The Moon is essentially a non-conducting body which has a tenuous atmosphere and no global magnetic fields. The solar wind plasma impacts directly the lunar day-side and is absorbed by the lunar surface. This creates a plasma void and forms a wake at the night side of the Moon.We study the properties and structure of the lunar wake for typical solar wind conditions using a three-dimensional hybrid plasma solver. Also, we study the solar wind proton velocity space distribution functions at close distances to the Moon in the lunar wake and investigate the effects of lunar surface plasma absorption and non-isothermal solar wind velocity space distribution functions on the solar wind protons there.Finally, we compare the simulation results with the observations and show that a hybrid model of plasma can explain the kinetic aspects of the lunar wake and we investigate the effects of the lunar surface plasma absorption and non-isothermal solar wind velocity distribution on the solar wind proton properties there.Godkänd; 2011; 20111114 (shafat); LICENTIATSEMINARIUM Ämnesområde: Rymdteknik/Space Engineering Examinator: Docent Mats Holmström, IRF Kiruna Diskutant: Senior Scientist Bengt Eliasson, Institute for Theoretical Physics, Ruhr-University, Germany Tid: Måndag den 19 december 2011 kl 10.00 Plats: Sal C, Rymdcampus i Kiruna, Luleå tekniska universitet
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Zamora, Merino Victor. "Development of Monitoring and Control Capabilities between Remote Robotic Systems and the METERON Infrastructure." Thesis, Luleå tekniska universitet, Rymdteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-69728.
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Raiti, Federico. "Efficient and Robust Attitude Determination and Control System Design for the MIST CubeSat." Thesis, KTH, Rymdteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-235968.
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This thesis investigated different configurations of the attitude determination and control system (ADCS) for the MIST satellite, to find a satisfying trade-off between computational demand and estimation/pointing accuracy. A model of the satellite dynamics was developed and used in a simulation. The designed ADCS consists of a discrete extended Kalman filter (EKF) and a model predictive control (MPC) controller tunable in different ways. The filter works with a linearization of the spacecraft dynamics model which is performed about the last attitude estimate and it is also capable of estimating the residual magnetic moment of the spacecraft without any initial guess. Three different models were used with the MPC and compared: a linear-like, state-dependent model, a model linearized around a fixed equilibrium point, and a model linearized around the last attitude estimate. The simulation, developed with Simulink, served as a testbed for the different tunings. From the simulation results, the filter proved to be capable of estimating the residual magnetic moment of the satellite with satisfying accuracy. Estimation and pointing requirements were met on average with a mean absolute estimation error of 0.8 deg and a mean absolute pointing error of 3.5 deg. This performance was achieved in face of measurement and model uncertainty.Det här examensarbetet undersökte olika konfigurationer av systemet för bestämning och styrning av orienteringen (ADCS) för MIST-satelliten för att hitta en godtagbar kompromiss mellan nödvändig beräkningskraft samt noggrannheten vid uppskattning av attityden. En modell för satellitens dynamik skapades och användes i simuleringarna. Det framtagna ADCS består av ett diskret utökat Kalmanfilter (EKF) och en ställbar avancerad reglerstrategi (MPC). Filtret arbetar med en linjärisering av rymdfarkostens dynamik kring den senaste uppskattningen av attityden. Vidare är den kapabel att uppskatta rymdfarkostens residuala dipolmoment utan några startvärden. Tre olika MPC-modeller användes och jämfördes: en linjär tillståndsberoende modell, en linjäriserad modell kring en fix jämviktspunkt samt en modell linjäriserad kring den senaste uppskattningen av attityden. Simuleringarna, utvecklade i Simulink, fungerade som en testplattform för de olika inställningarna. Resultatet från simuleringarna visade på att filtret var kapabelt att uppskatta rymdfarkostens residuala magnetiska moment med tillfredsställande noggrannhet. Krav på uppskattning av attityden och önskad attityd uppfylldes med en genomsnittlig absolut avvikelse av 0.8 respektive 3.5 grader. Denna prestanda uppnåddes trots osäkerhet i mätningar och modell.
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Carret, Rémi. "Mechanical Assembly Integration and Test of the Qualification Model for the EYESAT Mssion." Thesis, KTH, Rymdteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-235969.
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In this era of miniaturization and industrial needs for accessing space, nanosatellites are an appropriate and riskless answer. This paper examines the development and the progress of the mechanical assembly, integration and test (AIT) campaign on the CNES CubeSat demonstrator, EYESAT. This student nanosatellite, designed to observe the zodiacal light in the solar system, is actually in integration and testing phase; and will be launched in 2019. This thesis led the project from the structural and thermal model to the end of the qualification model assembly as well as the beginning of the tests campaign.I eran av komponentminiatyrisering och industriella behov för att nå rymden, är nanosatelliter en lämplig lågrisklösning. Detta arbete undersöker utvecklingen och progressionen av den mekaniska integration och testkampanjen (AIT) för CNES CubeSat-demonstrator EYESAT. Denna studentbyggda nanosatellit, som har som syfte att observera Zodiakalljuset i solsystemet, var under detta examensarbete inne i integrations-och provningsfasen med mål att skjutas upp i jordbana 2019. Detta examensarbete startade med de strukturella och termiska modellerna, forsatte med integrationen av kvalificeringsmodellen och avslutades med inledningen av kvalificeringstestkampanjen.
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Thierry, Maxime. "Developing and enriching a guidance library for the Earth Observation Satellite MicroCarb." Thesis, KTH, Rymdteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-235970.
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My Master Thesis takes place in the context of the MicroCarb mission. The goal of this mission is to identify the sinks and the sources of carbon dioxide on Earth in order to map them and to improve the knowledge of its cycle. To fulfill this mission, some particular guidance modes must be implemented in order to study their feasibility. My thesis consisted in defining and enriching the algorithms used to define the guidance laws, by implementing new tools and a new guidance law, and studying the induced performances in terms of data acquisition and with respect to the constraints related to the satellite. Alongside with this mission, the implementation of those elements support the development of the guidance library POLARIS, actual in its early phase, which is at first only dedicated to MicroCarb but which is intended to become multimissions. First, I describe the CNES as well as the guidance team I worked in. Then, the context of the Master Thesis is introduced. Once the context is established we will focus on the first elements I have been working on, as part of the Dazzling studies. Indeed, the spectrometer used in MicroCarb is very sensitive and has to be maintained at very low temperature. Thus the passive cooling mechanism must be protected from the Sunlight and from the light reflected by the Earth. I had to use a class of the Space mechanics library PATRIUS, called Assembly, in order to materialize the satellite and its numerous parts. Once implemented, I was able to perform some Dazzling Studies, highlighting some issues with the various strategies that were considered, and opening new perspectives. Moreover, a problem was detected on a crucial function of the guidance laws calculator. Once a new function was compiled, I had to made a cross validation using Scilab, and results were positive. This part will end with a Geometric Cape study, realized in order to quantify the influence of the satellite, and the MCV roll, over the Geometric Shifting. In the second part, we will introduce a guidance law which was not implemented initially, and on which I had to work during the last weeks of the thesis: The City mode. Although this mode is similar to an existing calibration mode, it has its own characteristics I had to take into account. The code for this acquisition mode worked well, but the results were not satisfying, considering the Dazzling problem and the kinematic constraints. Thus new strategies had to be considered, and more particularly the 2-scans mode. This mode brought a lot of satisfactions, but there is still more work to be done. This report ends with a general conclusion about my work and some perspectives which could be considered for future studies. I also present my personal contribution and some encountered difficulties I had to deal with.Examensarbetet fokuserade på rymduppdraget MicroCarb. Målet med detta uppdrag är att identifiera koldioxidsänkor och -källor på jorden för att kartlägga dem och förbättra kunskapen om deras cykler. För att uppfylla detta uppdrag måste vissa specifika styrningsmoder implementeras för att studera uppdragets genomförbarhet. Detta bestod i att definiera och förfina de algoritmer som användes för att definiera siktningslinjer, genom att implementera nya verktyg och en ny styrning samt studera prestandan när det gäller datainsamling och utifrån begränsningar hos satelliten. Detta uppdrag stöder utvecklingen av vägledningsbiblioteket POLARIS, i dess tidiga fas, som i första hand är avsedd för MicroCarb men som också är avsett att användas i flera kommande uppdrag. Arbetet inleds med en beskrivning av CNES, där examensarbetet utfördes, samt den grupp jag arbetade inom. Därefter presenteras motivation och sammanhanget. Sedan inriktas fokus mot de första elementen jag har arbetat med som en del av de bländande studierna. Spektrometern som används i MicroCarb är mycket temperaturkänslig och måste hållas vid mycket låg temperatur. Således måste den passiva kylmekanismen skyddas mot solljus samt från det ljus som reflekteras från jorden. En klass inom rymdmekanikbiblioteket PATRIUS, kallad Assembly, användes för att modellera satelliten och dess många delar. Därefter utfördes preliminära bländande studier, med fokus på några problem med de olika styrningsstrategier som föreslagits, vilket öppnade nya perspektiv. Dessutom upptäcktes ett problem med en avgörande funktion i siktlinjens räknare. När en korrigerad funktion sammanställts, utfördes en korsvalidering med mjukvaran Scilab, och resultaten var positiva. Denna del avslutas med en geometrisk studie för att kvantifiera påverkan av satelliten och instrumentrullningen på den geometriska skiftningen. Den andra fasen i arbetet var implementering av en ny funktionalitet kallad Stadsläget. Även om det här läget liknar ett befintligt kalibreringsläge, har det egna egenskaper som måste tas hänsyn till. Beräkningskoden för detta läge fungerade bra, men resultaten var inte tillfredsställande utifrån bländningsproblemet och kinematiska begränsningar. Därför beaktades nya strategier, i synnerhet ett nytt skanningsläget med två avskanningar. Detta läge gav bättre resultat, men behöver utvecklas ytterligare. Rapporten avslutas med förslag på fortsatt arbete och personliga reflektioner.
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Charbaut, Benjamin. "Robust and Agile Attitude Control for Triple CubeSat Eye-Sat." Thesis, KTH, Rymdteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-235972.
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Eye-Sat is a student-designed 3U-CubeSat, to be launched to a sun-synchronous orbit from where it will map the zodiacal light, a faint glare caused by the reflection of Sun on interplanetary dust. Such mission requires an accurate 3-axis attitude control, for which Eye-Sat is equipped with reactions wheels, magnetorquers, magnetometers and a star tracker. The star tracker can only be used for inertial pointing, which confines its use to shooting phases. A solution based on the remaining 3 equipment is proposed for the other mission phases, providing 3-axis pointing with high agility, for ground station tracking, at the cost of a slightly degraded accuracy. The magnetometers and magnetorquers work in closed-loop, while manoeuvres are performed in open-loop by the reaction wheels, which also ensure gyroscopic stabilisation of the spacecraft. Since this design relies on only one sensor, efforts have been put into making it robust to the imperfections of the magnetometers. Robustness to potential changes in the mission or the design has also been taken into consideration. Performance assessments carried out on a preliminary tuning have demonstrated the capacity of this magnetic-based mode to recover 3-axis pointing when exiting the survival mode, to provide a 3-axis pointing accuracy better than 8 deg in the worst case, and to sustain slews up to 0.87 deg/s in download.Eye-Sat är en 3U-CubeSat utformad och byggd av studenter. Den ska placeras i en solsynkron omloppsbana där den kommer att kartlägga zodiakljuset, en svag bländning producerad när solens ljus reflekterar på interplanetärt damm. Detta rymduppdrag kräver en precis reglering kring tre axlar och därför är Eye-Sat utrustad med fyra reaktionshjul, magnetspolar för kraftmomentgenerering, magnetometrar och en stjärnsensor. Stjärnsensorn kan endast användas för inertial attitydreglering, vilket begränsar användningen till fotograferingsfaser. En strategi baserad på de återstående regleringsdonen och sensorerna föreslås för de andra rymduppdragsfaserna, vilken ger treaxlig pekning för markstationsspårning, men med något sämre noggrannhet. Magnetometrarna och magnetspolarna arbetar i sluten reglering, medan manövreringen genomförs i öppen reglering med reaktionshjulen, vilka också säkerställer gyroskopisk stabilisering av rymdfarkosten. Eftersom denna utformning är beroende av endast en sensor är det kritiskt att göra den robust mot mätfel hos magnetometern. Robusthet mot potentiella framtida förändringar i utformningen har också beaktats. Prestandabedömningar som gjorts vid en preliminär inställning har demonstrerat att den magnetiska regleringen kan återställa treaxlig pekning när man lämnar den säkra regleringmoden. En treaxlig pekningsnoggrannhet bättre än 8 grader i värsta fall och vinkelhastigheter upp till 0.87 grader/s i nedladdningsfaser.
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Pettersson, Gustav. "Compact 3D Microscopy for Planetary Exploration." Thesis, KTH, Rymdteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-235974.
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We propose using grain-of-sand-scale microscopy (1-micrometre resolution) to study the microstructure and composition of planetary material in a fast, in-situ, solid-state device. We have constructed a small and light prototype instrument (100 grams, 0.3 litres) from commercial-off-the-shelf components, targeted for applications in miniaturised robotic exploration, mounted to a robotic arm, or used as a hand-held tool. This microscope employs a programmable LCD aperture to virtually record multiple perspectives, and a dome studded with LEDs surrounding the sample to control illumination. With this prototype microscope we have captured rich and intuitive raw images for a human observer, and reconstructed 3D surfaces and photometric properties of the samples. The broad applicability of this method is demonstrated by integration into a novel exploration concept in which sensor projectiles are launched from a rover into inaccessible environments. Our microscope can there deliver 3D-maps of the surfaces they encounter and extract relevant morphological properties. Our prototype device is evaluated using a range of lunar and planetary simulants. We argue that this microscope delivers large scientific value on its own, and context for other instruments, with small resource requirements similar to those of a camera alone.Vi presenterar en metod där mikroskopi med mikrometerupplösning används för att studera mikrostruktur och sammansättning på ytan av planeter. En liten och lätt prototyp (ca. 100 gram, 0.3 liter) av detta mikroskop konstrueras av kommersiellt tillgängliga komponenter och utan rörliga delar. Det är speciellt anpassat för applikationer inom robotik eller som ett handhållet instrument. Mikroskopet använder en programmerbar LCD-apertur för att virtuellt fånga bilder från flera perspektiv samt en kupol med lysdioder för att styra belysningen av provet. Med denna prototyp har vi genererat detaljrika och intuitiva rådata för människor samt implementerat metoder för att rekonstruera 3D-formen och de fotometriska egenskaperna hos provet. Vi understryker användbarheten genom att integrera prototypen i ett nytt koncept för utforskning av planeter, där instrumentet monteras i projektiler som avfyras från en strövare till annars oåtkomliga platser. Därifrån levererar vårt mikroskop 3D-formen samt relevanta morfologiska data om den ytan som påträffas. Vi utvärderar metoden vidare med en uppsättning material som liknar regolit från Månen respektive Mars. Vi anser att denna metod levererar stort vetenskapligt värde samtidigt som den har små resursbehov liknande en enkel kameras.
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Sveinbjarnarson, Unnar Már. "Anomaly Detection based on Boeing 757-200 Flight Data." Thesis, KTH, Flygdynamik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-239042.
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This paper deals with anomaly detection from collected flight data for a Boeing 757-200currently in use by Icelandair. Previous work on anomaly detection using generated datahas been shown to give good results using multiple linear regression models. Using a similarapproach the paper addresses how the amount of data effects the models ability to detectanomalies. Simple regression approach is compared to a quadratic one and practical use ofmaintenance data in this context is explored. Finally different model variations are investigatedto attempt further root cause analysis of faults.
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Still, Vincent. "Thermal Control Design and Simulation of a Space Mission." Thesis, Luleå tekniska universitet, Institutionen för system- och rymdteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-71784.
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The following document describes an example mission, which originated from a real life concept of an imaging satellite in a Sun Synchronous Orbit (SSO)around Earth. This report takes the reader through the thermal analysis and evaluation of space equipment performed with Airbus Space & Defence’s Systema/Thermica tool, at Space Structures GmbH. It details the full process of designing a thermal control system for a space project. The project started from a CAD file which was converted into a Geometric Mathematical Model (GMM) inside Thermica. This process requires an extensive knowledge of not only the software, but also the technical background behind what happens to a satellite in such an extreme environment. This thesis addresses this by showing a step-by-step approach of a full thermal evaluation, starting with the required theoretical background of the thermal environment and the different passive and active thermal design techniques. The next step involves gathering the required input information for the software; such as defining the conductance values between the components and calculating the per node power dissipation for each component considering each operational mode. The final step includes the designing, simulation, iteration and presentation of the temperature results across the spacecraft thermal model. The results of the initial simulation showed that some sensitive components were not within the specified temperature requirements, and therefore both radiators and heaters were sized and introduced to the model. After the third iteration of thermal control, the sensitive components’ temperatures were observed to be within the allowable margins of an ECSS Phase A study. This thesis can serve as a guide and complete document for future missions which plan the design of a Thermal Control System of a satellite in orbit around Earth.
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Haverkamp, Kalli. "An Analysis of the New Threat Environment for Satellites." Thesis, Luleå tekniska universitet, Institutionen för system- och rymdteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-71605.
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Dundar, Ismail Ugur. "Improvement of a Space Surveillance Tracking Analysis Tool." Thesis, Luleå tekniska universitet, Rymdteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-71905.
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Since the beginning of space exploration, the amount of space debris has increased with thedevelopment of new space technologies. In fact, when a collision happens, new space debris aregenerated. Hence, collision risk between space debris and operational satellites rises. The purpose ofa surveillance network system consists of the detection of space objects, their classification and theirtracking. To avoid collisions, space debris objects’ orbit must be computed with sufficient accuracy. The goal of this thesis is the improvement of a pre-existing Space Surveillance and Tracking AnalysisTool. The tool is able to simulate different observation scenarios for radar or optical observer,which can be space-based or ground-based. To enhance the orbit determination, an ExtendedSquare Root Information Filter is implemented and incremented with a Smoother. Smoothers havebeen implemented for the existing filters as well, such as the Extended Kalman Filter and theUnscented Kalman Filter. A bias estimation method was added as part of the OD for all filter types.Additionally, different outlier detection methods were implemented for the automatic detection ofoutliers within the measurement data. To find the optimum orbit determination interval, differentscenarios were considered in LEO, MEO and GEO orbits. The methods were implemented anddifferent scenarios for validation will be discussed. A wide discussion on the methods implementationand their validation on different scenarios is presented, together with a comparison of the orbitdetermination results with the other filters. All the recently implemented features increase the efficiency of the tool to simulate the differentscenarios and enhance the tracking of space debris objects.
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Samuelsson, Jonas. "A study into relative navigation methods for automatic probe and drogue air-to-air refuelling." Thesis, Luleå tekniska universitet, Rymdteknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-81004.
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As the aerospace industry moves into more automatic systems and fully automatic systems the need for automatic air to air refuelling is becoming essential to create an optimal aircraft system. It is not only needed for UAVs but also for piloted aircraft. For the aircraft to connect with the hose is a difficult procedure where a lot of things can go wrong. Creating an automatic system will remove any human error out of the procedure to create a more efficient refuelling procedure. This study is taking a look at relative navigation methods to connect the receiver aircraft with the hose in a probe and drogue refuelling system which can be used for an automatic aircraft system for refuelling. To investigate different relative navigation methods a simulation environment was built using the relative position between each part of the system, the tanker, the hose, the drogue and the receiver. The system environment effects are also implemented to create an accurate environment that includes turbulence, wake effects, wind and bow wave effects. The complexity of each part differs from each other. The two aircraft, tanker and receiver, are modelled in 1 and 3 degrees of freedom where the hose and drogue is modelled in 5 degrees of freedom to simulate the procedure. Using this simulation environment two different methods were tested, a straight on approach where the probe of aircraft aimed to always be aligned with the drogue and an offset approach where the receiver aimed to try to predict the movement of the drogue. The findings from the simulation showed that analysing the bow wave effect on the drogue to then predict its movement by approaching with an offset was the most optimal approach. It allowed the receiver to do fewer movements during critical parts of the refuelling procedure and also were able to successfully dock during turbulent environment I can conclude that using relative navigation that using a probe and drogue air to air refuelling an automatic system should be able to work. The simulation can be expanded upon to create a more realistic environment that can give a more accurate representation of the real world dynamics. The aerodynamics of the aircraft need to be expanded upon and the aerodynamics of the disturbances can be more accurately implemented.
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Knöös, Franzén Ludvig. "An Ontological and Reasoning Approach to System of Systems." Licentiate thesis, Linköpings universitet, Fluida och mekatroniska system, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-175766.
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System-of-Systems (SoS) are all around us and are becoming more common in today’s highly interconnected world. Systems are connected with other systems and have strong dependencies with their operational environments. This leads to an increased level of complexity and risk during product development. A holistic view, and an SoS perspective, is consequently needed in order to develop an early understanding of the available design spaces for new system solutions. This thesis suggests a method that has been developed for this purpose, and to meet the demand for a more holistic product development. Overall, the method consists of two correlated approaches that show how a design space for SoSs can be generated and later processed with, for example, design space reductions. Search and Rescue (SAR) operations have been used as examples of typical SoSs throughout this work and in the development of the presented method. An architecture framework has been used to introduce a standardized and consistent way of understanding the relationships that exist between needs, capabilities and functions. This approach can consequently be used to generate a design space of functions to be performed to meet the overarching needs of an SoS. The second approach has been based on ontology and description logic reasoning. Ontology has here been used to represent an SoS design space with, for example, available SAR assets and their relationships with the operational environment. An SoS representation in an ontology model introduces additional expressiveness and the design space processing capabilities needed for a holistic design process and product development. Based on these results, this thesis and its suggested method and approaches contribute to holistic product development from an SoS perspective.Additional funding agencies: Saab Aeronautics.
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Seidel, Ferdinand. "Integration, impementation and validation of a simulation environment of a UAV Sense and Avoid System." Thesis, Luleå tekniska universitet, Rymdteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-84648.
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The steadily increasing amount of air transportation in the field of manned and unmanned aviation, as well as new requirements induced by technological innovations cause more and more complex avionic system developments. One of the most important safety requirements in aviation is the avoid-ance of mid-air collisions. In order to minimize such dramatic events, commercial manned aircraft are equipped with the “Traffic Alert and Collision Avoidance System (TCAS)”to support the pilots of both endangered aircraft by traffic advisories. In the booming field of unmanned aviation, collision avoidance needs to be autonomous, which will achieved by complex “Sense and Avoid” systems. Com-bining information from multiple detection sensors to minimize information uncertainties and neglect the disadvantages of each sensor as a single system is the base for an operational S&A system for Unmanned Aerial Vehicles (UAVs). The aircraft will use existing traffic instruments such as a tran-sponder for the reception of automatic dependent surveillance – broadcast (ADS-B) data from other aircraft, TCAS and additional electro-optic and radar-based sensors to compensate the lack of an on-board pilot. All this data can be used in a logical composition to provide the UAV a better situational awareness of the airspace and to avoid an intruding aircraft in case of emergency. To support the development of a “Sense and Avoid” system, the company Airbus Defence and Space is developing a dedicated simulation environment. It simulates collision scenarios between aircrafts to integrate, verify and validate the system under development. At this point the mathematical models of the sensors need to be integrated in the simulation environment in order to increase the degree of realism. As a contribution for further completion of the system, this master thesis is concerned with the integration of the existing models, implementation and improvement of missing models, visualization of this system to the PIC and the presentation to Airbus D&S’s customer.
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Pellnäs, Adrian, and Johanna Sandeberg. "Conceptual Design of a Small Size Unmanned Air Vehicle : Part A: Aerodynamic Performance and Structural Design." Thesis, KTH, Skolan för teknikvetenskap (SCI), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-297886.
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In this report, the conceptual design of an unmanned aerial vehicle (UAV) and aerodynamic analysis is treated. The project was split into two groups, one group would do the aerodynamic analysis, and the other group would do the performance analysis. The plan was to create a UAV capable of surveying life stock, large farmlands, wildlife, and also reindeer husbandry. This demanded that the aircraft had to be able to easily launch from all types of locations. To solve this the plane was designed for vertical take-off and landing capabilities (VTOL). The study includes the selection and performance testing of an airfoil, aerodynamic performance of the wing, and the wing's geometry. It also includes stability analysis, structural design, and CAD creation. The majority of this work was done by combining the usage of the design tool XFLR5 with CAD from Solid Edge and equations done in MATLAB. The aircraft accomplishes our goals to have it be VTOL functional. It has a flight time of over 2 hours and weighs less than 5 kg. Its cruise speed lies at 12 m/s. It is also possible to create a detailed design and to produce the aircraft with relative ease and low cost. Its dynamic stability is however not optimized and further work is needed if optimized stability is desired.
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Nyhlen, Anna. "Experimental Investigation of the Thermal Performance and Pressure Loss in Additively Manufactured mini-channels." Thesis, Luleå tekniska universitet, Institutionen för system- och rymdteknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-86277.
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Industrial gas turbines reach temperatures of 1500-2000K at high rotational velocities which means that much effort is spent on the design of an efficient cooling system. With the recent advances of the additive manufacturing (AM) industry, new design opportunities have open up for many industries and applications, including the design of cooling systems. However, a significant surface roughness will be present in AM components compared to traditionally manufactured components. An increased surface roughness inside a channel will affect both the heat transfer and pressure loss. The performance of AM channels are therefore not fully known and needs to be examined experimentally on the actual material to fully capture the effects of the increased surface roughness. The aim with this project is to experimentally investigate the thermal performance and pressure losses experienced in AM channels due to surface roughness. This was done by using a Steady State Heat Transfer rig which was assembled and verified. AM and aluminium test channels were mounted in a copper block which was insulated and heated up by electrical heaters. The test channels were then subjected to an air flow of constant mass flow. Temperature and pressure measurements were made at the inlet and outlet together with mass flow measurements and copper block temperature measurements. The Nusselt number and Darcy friction factor were used to evaluate the heat transfer and pressure losses experienced in the channels. The results showed that the heat transfer and friction factor increased significantly for the AM channels compared to smooth channels. Both the heat transfer and friction factor increased when the relative roughness of the channels increased. This project was executed at Siemens Energy in Finspång at the Fluid Dynamic Laboratory and is a part of the work of obtaining thermal performance data for mini-channels manufactured by AM.
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Josses, Roxane. "Data Fusion between Inertial and Optical Sensors for Earth Observation Satellite Line of Sight Estimation and Stabilization." Thesis, KTH, Rymdteknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-299359.
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The line-of-sight (LoS) pointing and stability requirements of Earth observation satellites are becoming increasingly stringent. The microvibrations that disturb the LoS are therefore no longer negligible, and many studies are focusing on the estimation of these microvibrations and on mitigation strategies, on platform and payload levels. Disturbances of the LoS can be seen by image processing algorithms that provide high-frequency information. In this paper, a novel method is proposed to fuse these optical data with inertial data using a Kalman filter to obtain the best LoS estimation. To demonstrate the performances of this fusion, a simulation tool is developed on Matlab/Simulink and three estimators, corresponding to three image processing techniques (fixed scene, scrolling scene and scene tracking) are tested. The stabilization of the LoS is performed by adding a fast-steering mirror in the optic path of the telescope. Results indicate that the fusion with optical data enables to include in the LoS estimation the instrument motion, which can differ from the platform motion at high frequencies. Using this estimation, stabilization results are approaching the challenging pointing requirements.Siktlinjens (LoS) peknoggrannhet och stabilitetskrav för jordobservationssatelliter blir allt striktare. Mikrovibrationerna som stör LoS är därför inte längre försumbara, och många studier fokuserar på uppskattningen av dessa mikrovibrationer samt på strategier för att minska dessa, både plattforms- och nyttolastnivåerna. Störningar i LoS kan ses av bildbehandlingsalgoritmer som ger högfrekvent information. I detta arbete föreslås en ny metod för att slå samman optiska data med tröghetsdata med hjälp av ett Kalman-filter för att uppnå bästa LoS-uppskattning. För att visa prestandan för denna datasammanslagning utvecklades ett simuleringsverktyg i Matlab/Simulink och tre uppskattningsalgoritmer, motsvarande tre bildbehandlingstekniker (fast scen, rullningsbild och scenspårning), testades. Stabiliseringen av LoS utförs genom att lägga till en snabbspegel i teleskopets optiska väg. Resultaten visar att sammanslagningen med optisk data gör det möjligt att inkludera instrumentets rörelse i LoS-uppskattningen, som kan skilja sig från plattformens rörelse vid höga frekvenser. Med hjälp av denna uppskattning närmar sig stabiliseringsresultaten de utmanande pekkraven.
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Priebe, Zakarias, and Frank Alexander Hasp. "An aeroelastic prediction model for slender wings in supersonic flow." Thesis, KTH, Flygdynamik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-299363.
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Aeroelasticity is a multidisciplinary subject encompassing several fields of study. Aeroelastic behaviour is defined by the relation between inertial-, elastic- and aerodynamic forces that appear in dynamic systems in steady- or unsteady conditions. Published literature in the field of supersonic aeroelasticity does not generally provide a thorough demonstration of application. Further, high precision methods incorporated in commercial software often require an extensive preparatory phase and entail a significant computational cost. Thus, the absence of rapid and affordable estimation models for supersonic aeroelastic analyses appears evident. Hence, the scope of this report is to demonstrate and describe the development of an estimation model for aeroelastic analysis of wing structures. The developed model should generate rapid results indicative of the true aeroelastic behaviour of slender wings with thin airfoil geometries in varying supersonic flow conditions. The wing is modelled as a structural finite element beam with properties based on Euler bending- and St. Venant torsion theory. Moreover, two quasi-steady aerodynamic models of Piston theory and Unified Oscillatory Supersonic-Hypersonic theory are presented. The aerodynamic models are implemented in the finite element wing model through strip theory. The computational aeroelastic model is assembled to perform aeroelastic analyses in steady- and quasi-steady conditions. The developed models are evaluated against the previously conducted aeroelastic studies of the Torii Matsuzaki wing by Hiroshi Torii and Yuji Matsuzaki and Marius-Corné Meijer. The conclusion regarding the developed model for supersonic aeroelastic analysis is that it generates results rapidly for varying geometries and flow conditions. Unfortunately, when analysing the aeroelastic behaviour of wings with double-symmetric airfoils, a paradox of infinite stability ensues. Due to lack of modern experimental data and time limitations, no further validation of the aeroelastic model is presented. Thus, the developed aeroelastic prediction model cannot presently be fully evaluated as it requires additional work and validation.Aeroelasticitet är ett tvärvetenskapligt ämne som omfattar flera studieområden. Aeroelastiskt beteende definieras av förhållandet mellan tröghets-, elastiska- och aerodynamiska krafter som uppträder i dynamiska system under stabila- eller instabila förhållanden. Publicerad litteratur inom området överljudsaeroelasticitet är ofta allmängiltig och ger inte en grundlig demonstration av tillämpningsmetoder. Vidare baseras kommersiell programvara inom området generellt på beräkningstunga metoder och kräver ofta en omfattande förberedelsefas vilket medför betydande beräkningskostnader. Således förefaller sig avsaknaden av snabba och prisvärda uppskattningsmodeller för överljudsaeroelastiska analyser uppenbar. Följaktligen skall denna rapport omfatta och beskriva utvecklingen av en aeroelastisk modell som genererar snabba resultat. Resultaten skall vara indikativa av det verkliga aeroelastiska beteendet hos smala vingar med tunna vingprofiler i varierande överljudsflöden. Den strukturella vingmodellen är uppbyggd med hjälp av finita elementmetoder och är modellerad såsom en balk med egenskaper baserade på Eulers böjnings- och St. Venants vridningsteori. Vidare presenteras två kvasi-stabila aerodynamiska modeller benämnda Piston theory och Unified Oscillatory Supersonic-Hypersonic theory. De aerodynamiska modellerna implementeras i vingmodellen genom stripteori. Den framtagna aeroelastiska beräkningsmodellen möjliggör aeroelastiska analyser av vingkonstruktioner i stabila och kvasi-stabila förhållanden. De utvecklade modellerna utvärderas mot tidigare aeroelastiska studier av Torii Matsuzaki-vingen genomförda av Hiroshi Torii och Yuji Matsuzaki och Marius-Corné Meijer. Slutsatsen gällande den utvecklade modellen för överljudsaeroelastisk analys är att den genererar resultat snabbt för varierande vinggeometrier och flödesförhållanden. Vid analyser av det aeroelastiska beteendet hos vingar med dubbelsymmetriska profiler uppstår dessvärre en paradox av oändlig stabilitet. På grund av bristande tillgänglighet av modern experimentell data och tidsresurser presenteras ingen ytterligare validering av den aeroelastiska modellen. Således kan den framtagna modellen inte fullständigt bedömas utan kräver ytterligare arbete och validering.
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Ruhlmann, Sébastien. "The FLARE Suit: A protection against solar radiation in space." Thesis, KTH, Rymdteknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-261181.
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FLARE Suit är en enhet som används för att skydda astronauter från intensiv partikelstrålning när de reser ut ur magnetosfären på framtida Deep Space-uppdrag. Denna dräkt kan skydda mot solpartiklar som på grund av sin höga densitet kan orsaka akut strålningssjuka och leda till överdriven förstöring av inre organ (mag- tarmkanalen, nervsystemet, blodbildande benmärg) och i värsta fall till döden. Dessa symtom blir mycket starkare utanför jordens magnetosfär, vid månen eller på väg till Mars. För tillfället studeras FLARE-dräkten som ett komplement inombords till det befintliga skyddet från rymdfarkostens struktur, men även för rymdpromenader utanför rymdfarkoster och på andra planeter kan övervägas. FLARE består av en uppblåsbar dräkt som fylls med vatten när det behövs. Under uppskjutning är dräkten tom och lätt tack vare att den vid användning utnyttjar vattnet som redan finns ombord på människobärande rymdskepp. Den fylls på några minuter, och att använda sig av individuella skyddsdräkter är betydligt mer materialsnålt än att täcka farkosten med paneler. Dessutom ger vatten högt skydd per massa. Efter hydrogenerade bornanorör (HBNNT) och högdensitetspolyeten (HDPE) är vatten det tredje högsta skyddsmaterialet mot solstrålning. I framtiden kan vatten även komma att kompletteras med salt vilket kan hjälpa mot (neutronerna i) sekundära partiklar då salt har en hög neutronblockeringseffektivitet. Slutligen har FLARE en helt adaptiv flerskikts- och formändringsdesign som möjliggör anpassning i realtid, beroende på solstrålningens intensitet, antalet involverade astronauter, tidsramen och vattenförsörjningen. Den preliminära utformningen av FLARE-dräkten beskrivs och strålningssimuleringar utförs i en 1D-miljö inom Columbus-modulen, vilket visar en minskning av strålningsexponeringen med 50 procent, med 3,5 till 4 centimeter vatten, beroende på salthalten. Därefter byggs en 3D-miljö, som inte är testad än. För denna miljö har bedömningar av relevanta 3D-modeller gjorts, Columbus-modulen har konstruerats och designval anpassade för mänsklig morfologi har gjorts. Matlab-koder har skrivits också för att bygga och forma en 3D-dräkt ovanpå den mänskliga modellen, följt av olika strålskyddsstrategier.The FLARE Suit is a device that aims to protect astronauts from intense solar radiation when travelling out of the magnetosphere on future Deep Space missions. This suit is an emergency solution against solar particles that, due to their high density, can cause acute radiation sickness and lead to excessive destruction of internal organs (gastro-intestinal system, nervous system, blood forming bone marrow) and eventually to death. These symptoms will be a lot stronger out of the Earth’s magnetosphere, towards the Moon or Mars. For now, the FLARE Suit is being studied in the intra-vehicular environment as a supplement to already existing shielding provided by the spacecraft’s structure, but extra vehicular activities in space and on other planets can be considered. It consists of a bladder-suit that is to be filled with water when needed, the water being already present on any human carrying spacecraft. The suit can be deployed within a few minutes, be very lightweight at launch due to the resource utilization of on-board water, and does not use a lot of material compared to a fully shielded module since it is fitted to the individual human body. Furthermore, water has been shown to provide a decent shielding per mass capability, the third most shielding efficient material after hydrogenated boron nanotubes (H-BNNT) and high-density polyethylene (HDPE). Water could eventually be complemented with salt that shows high neutron blocking efficiency and could help shield from neutrons (present in secondary particles). Finally, it has a fully adaptive multilayered and shape changing design which allows for real-time scenario adaptation depending on the intensity of the solar radiation, the number of astronauts involved, the time frame and the water supplies. Preliminary design of the FLARE suit is show cased and radiation simulations are being performed in a 1D environment within the Columbus module, highlighting a fifty percent reduction in radiation exposure with 3.5 to 4 centimeters of water, depending on the salt content. Afterwards, a 3D environment is being built, however not tested. For this, selection of a relevant 3D human model, construction of the Columbus module and design choices on human morphology have been made. Matlab codes also were written to build and shape the 3D suit on top of the human model, following diverse radiation shielding strategies.
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Barrére, Vincent. "Viability of CREO Simulate : (CAD software’s module) as a thermal simulation software." Thesis, KTH, Flygdynamik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-261206.
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The analysis of the reliability of CREO simulate will be done step by step. First of all, the precisionof the simulation has to be measured thus a comparison with simple theoretical computations willbe done. Then, the scope of the capacity of the software will be analyzed and if elements deemednecessary to thermal simulations are missing, back up solutions are to be found. Also, the influenceof the meshing will be studied and measured to ensure that the software guarantee convergence evenin the hand of persons unfamiliar with simulations.In parallel, one will experiment with realistic hardware that could be used to compare reality withthe simulations. Those experiments will be handmade using regular materials from the company.
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Lawniczek, Baptiste. "Evolution of the methodology of weight estimation and engine feasibility in preliminary design." Thesis, KTH, Flygdynamik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-261216.
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Som en del av Aerospace Engineering masterprogrammet som jag följde på KTH från augusti 2017 till juni 2018, fick jag slutligen en självständig studie i form av ett avhandlingsprojekt. Jag fick möjlighet att slutföra mitt 6-månaders examensprojekt på Safran Aircraft Engines i Villaroche, Frankrike. Safran är en internationell högteknologisk grupp som arbetar inom flygplanets framdrivning och utrustning, rymd- och försvarsmarknader. Som en del av de mekaniska aktiviteter som genomförs vid Produkt Innovation Lab är genomförandet av en för-dimensioneringsmetod för motorkonstruktioner nödvändiga för att få en uppfattning om för-dimensionering tidigare inom projektet och inom en rimlig tidsrymd. Huvudsyftet med detta projekt är att utveckla metoden som gör det möjligt att göra viktstatus och genomförbarhetsbedömningar av motorramkomponenterna i en preliminär konstruktionsfas och inom en begränsad tid. Detta papper fokuserar mer exakt på en äldre kommersiell motor mellanram. Denna metod måste leda till att en konsekvent modell skapas som ligger närmare kraven och specifikationerna. Slutsatsen av rapporten är att den implementerade pre-designmetoden möjliggör resultat med avseende på viktstatus och genomförbarhet som överensstämmer med specifikationerna. Vidare är beräkningstiden i linje med förväntningarna. Detta projekt har äntligen tillåtit att skapa en modell som kommer att tas som referens för att utveckla och designa nya motorer som har en konfiguration som liknar äldre kommersiella motorer.This paper aims to develop and to validate a methodology to realize pre-sizing studies on aircraft engine structural frames for Safran Aircraft Engines Product Innovation Lab activities. The members of this team are in charge of creating new propulsion systems architectures in accordance with product strategy guidelines or airframer needs. Aerospace industry being highly competitive, the Product Innovation Lab must be able to respond quickly and precisely to any demand emerging from aircraft manufacturers or strategy team.The main purpose of this project is to improve the methodology permitting to make weight status and feasibility estimations of the engine frame components in a preliminary design phase and in a limited amount of time. This methodology must lead to the creation of a consistent model that is closer to the requirements and specifications imposed. This paper more precisely focus on legacy commercial engine structural frame. Reflection has been conducted on the creation of a simplified parametrized model of an existing commercial engine structural frame and on the way to mesh it in order to find a good compromise between results fidelity and computation time. Regarding the weight status and feasibility results obtained with a first model, an optimization of the model configuration has finally been conducted in order to get results that fit with the specifications.Conclusion of the report is that the pre-sizing methodology can be adapted to existing commercial engine structural frame configuration. Results obtained in terms of weight status and feasibility are in accordance with the specifications and the computation time is in agreement with the expectations. It has permitted to create a model that will be taken as a reference to develop and design new engines having a configuration similar to the legacy commercial engine considered in this study. For that purpose, iterations and optimizations will be conducted on the simplified model implemented during the project in order to determine a new configuration of the pre-sized intermediate frame model which sticks with reality i.e. that respects the provided feasibility specifications.Note that due to the public nature of this report, sensitive information and data used and obtained during the project have been removed from the present paper. Nevertheless, the methodology followed has been presented and discussed in detail. Relative deviations between the results obtained and reference values have also been exposed in order to give the reader an idea of implemented model consistency.
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Yezeguelian, Axel. "Modelling and Simulation of a Propulsive Hybridisation for a Light Fixed-wing Aircraft." Thesis, KTH, Flygdynamik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-261222.
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Propulsive hybridisation fits in with the sustainable development policies of many companies which are part of the transportation industry. Actually, it makes it possible either to reduce fuel consumption or to improve the aircraft performance at a fixed fuel burn. However, the current technologies of batteries restrain a more regular use in light aviation. For this project this issue is confirmed as both the quasi-static performance assessment and the dynamic studies show that the endurance objective cannot be improved with Li/Ion batteries. However, it is possible to act directly on the engine performance by placing a thermal energy recovery system on exhaust gas pipes to take advantage of their high temperatures, greatly boosting the aircraft performance in cruise.Hybridisering av framdrivningssystem passar in med hållbar utvecklingspolitik av många företag inom transportbranschen. Faktiskt tillåter det antingen att minska bränsleförbrukningen eller att förbättra flygplans prestandorna. Ändå är aktuella batteritekniken fortfarande ett problem för en mer frekvent användning av hybridisering förlättflyget. För det här projektet bekräftas det eftersom kvasistatiska och dynamiska studierna visar att hybridsystemet med aktuella Li/Ion batterierna förbättrar inte flygdurationen. Ändå är det möjligt att ingripa på motorprestandorna genom att återanvända värmeenergin av avgas för att förbättra flygdurationen.
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Maaroufi, Helmi, and Zhen Li. "Design of a Solar-powered Unmanned Aerial Vehicle for Surveillance." Thesis, KTH, Skolan för teknikvetenskap (SCI), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-152803.
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The degree project we were assigned consists of designing an environment-friendly Unmanned Aerial Vehicle (UAV) that can fly at least one hour. In this case the type of energy used for power system is solar energy as a clean energy.
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Shwan, Kurdi Mir. "Nonlinear Attitude Control ofa Generic Aircraft." Thesis, KTH, Flygdynamik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-261696.
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Determining suitable controllers for the process of evaluating dynamic per-formance of multiple versions of an aircraft’s aerodynamical, geometric and propulsive properties in its conceptual stage is an expensive task.In this report a proposition is made to utilize a generalized feedback lin-earizing controller that o˙ers the aircraft designer valuable insight into the manoeuvre performance of their aircraft. This is carried out by first estab-lishing fundamental requirements for a controller capable of treating a generic airframe, and formulating the resulting control laws.It is shown in this report, that with a suÿciently simple aerodynamic and propulsive model explicit feedback linearization is possible with satisfactory performance and robustness. Whereas it would be necessary to implement INDI if explicit inverse mappings are not obtainable. Which in turn would introduce additional tuning parameters.Robustness verification is performed in two stages, firstly by introducing a high model uncertainty within the flight control system and showing, via simulation, that the control system successfully performs desired multi-axial manoeuvres whilst managing to maintain the induced side slip below 0.1◦. Secondly by disturbing the aircraft with a discrete side slip. Critical side slip disturbance angle was found to be considerably larger than that for regular aircraft entailing that the used case study may be somewhat over dimensioned with respect to yaw control authority.
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Falquier, Rene. "Longitudinal Flight Mechanics of Paraglider Systems." Thesis, KTH, Flygdynamik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-261698.
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This project outlines a cost-effective numerical simulation method for the analysis of the longitudinal mechanics of paraglider systems. It is built on static stability methods for the analyses of low subsonic aircraft, non-linear lifting line methods for aerodynamic parameterization, and frequency domain analysis methods derived from system theory. Paragliders possess a glide polar in the range of ≈ 25-60 km.h−1 and display underdamped dynamic responses dominated by a long-period mode. The simulation results for performance and dynamic response are qualitatively valid relative to experimental data and in the same order of magnitude.Projektet handlar om utveckling och utvärdering av en kostnadseffektiv simuleringsmodell för longitudinella frihetsgrader av skärmflyg. Modellen är byggd med fundamentala metoder för stabilitetsanalys av låghastighetsflygplan, ickelinjära liftingline metoden för aerodynamikanalys samt frekvensanalys från systemteori. Ett skärmflygs glidepolar är definierad på hastighetsintervallet ≈ 25-60 km.h−1 och visar ett underdämpat dynamiskt svar med lång period. Simuleringsresultaten för prestanda och dynamisk stabilitet ¨ar kvalitativt giltiga i förhållande till experimentella data och visar samma magnitud.
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Lejon, Alexander. "Creation and Validation of Early Stage Conceptual Design Methodology for Blended WingBody Aircraft." Thesis, KTH, Flygdynamik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-261700.
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The current design paradigm for developing tube-and-wing style aircraft has been well documented in literature. This research attempts to develop and val-idate a similar design methodology to what is presently utilized for tube-and-wing based aircraft, but has so far not been successfully implemented for the blended wing-body. This construction has no clear distinction between the lift generating surfaces and the cargo carrying structure. The methodology that was developed included the concatenation and validation of low-fidelity, low speed and low complexity aerodynamic models in order to allow for quick and simple analysis of a large number of possible geometries. This enables the user eÿciently determine the most promising candidate geometries for further study and/or development. Known issues with the low velocity and low com-plexity aerodynamic models include the absence of shock wave modelling, an important part in determining the aerodynamic performance of a lift generat-ing surface. The result of this work is the creation and documentation of a procedure for early-stage design of a blended wing-body airframe. However, due to convergence issues with the high-fidelity CFD solver, the methodology could not been validated for transonic flow. It can thus be only considered valid for flow velocities for which the Prandtl-Glauert correction is valid.Den befintliga konstruktionsmetodiken för utveckling och design av flygfarkoster är väl dokumenterad i tidigare publicerad litteratur. Detta arbete ämmar utveckla och validera en liknande metodologi som redan existerar för de väl etablerade flygplansgeometrier som baseras på cylinder/vingar-principen. Metoden som utvecklades inkluderade sammansättaning och validering av tidigare existerande lågupplösta samt lågkomplexa aerodynamiska modeller avsedda för beräkning av flödesekvationer för inkompressibel, friktionsfri och stationär strömning. Detta var avsett att möjliggöra ögonblicksvalidering av en föreslagen sammansmält kropp/vinge-geometri med speciell fokus på vissa prestationsbaserade nyckeltal. För cylinder/vinge-geometrier är dessa lågupplösta metoder i litteraturen väletablerat inexakta på grund av en avsaknad av stötvågsmodellering, men då stora delar av de lyftkraftsgenererande ytorna för-ändrats på en sammansmält kropp/vinge är inte nödvändigtvis detta sant för den typen av flygplan också. Då de högupplösta, mer komplexa höghastighetssimuleringarna inte konvergerade inom den utsatta tiden kan den föreslagna metodiken endast anses giltig för det intervall av flödeshastighet vari PrandtlGlauerts korrektionsfaktor stämmer väl överens med verkligheten.
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Philippe, Alexis. "Optimisation of an aeronautic production line through the managementof tools and the shortage of items." Thesis, KTH, Flygdynamik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-261701.
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This thesis work is part of a process to ensure the production ramp-up of the A320neo aircraft pylons at Airbus Saint-Eloi factory (Toulouse). The aim of the project was to optimise the production management in order to sustain the transition to a serial production of the assembly lines. The objective of the thesis work was to develop a model to prevent the downtime of the production lines caused by the shortage of the assembly lines or the unavailability of tools on workstations.Firstly, the work investigates the existing models in order to understand the causes of stocks variability. Performance of tools was determined with the Markov chain model. Then, the work provides a method to forecast production needs in terms of items and tools. An algorithm was developed to collect and process the data on the existing resources in order to compare it to the forecasted needs. Solutions were designed to identify the causes of the shortages on the production lines. In addition, by analysing the trends of the shortage of stocks and the availability of tools on workstation, a forecast of long term constraints for production is possible. The method showed promising results to identify and manage the missing items and tooling on the workstations.Denna avhandlingsarbetet en del av en process för att säkerställa produktion ramp-up av A320neo-flygplanets pyloner på Airbus Saint-Eloi-fabriken (Toulouse). Syftet med projektet var att optimera produktionshanteringen för att upprätthålla övergången till en serieproduktion av monteringslinjerna. Målet med avhandlingsarbetet var att utveckla en modell för att förhindra driftstopp av produktionslinjerna som orsakats av bristen på artiklar eller om verktyg på arbetsstationerna. För det första undersöker arbetet de befintliga modellerna för att första° orsakerna till lagerförändringar. Utförandet av verktyg bestämdes med Markovchain-modellen. Sedan ger arbetet en metod för att förutse produktionsbehov i termer av artiklar och verktyg. En algoritm utvecklades för att samla och bearbeta data på befintliga resurser för att jämföra den med de prognostiserade behoven. Lösningar utformades för att identifiera brist till bristerna på produktionslinjerna. Genom att analysera trenderna om brist på lager och tillgången till verktyg på arbetsstationen ¨ar det dessutom möjligt att prognostisera långsiktiga produktionsbegränsningar. Metoden visade lovande resultat att identifiera och hantera de saknade artiklarna och verktygen på arbetsstationerna.
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Nicolle, Mathias. "Mechanical and structural conceptof the ISS microgravity experimentpayload: AtmoFlow." Thesis, KTH, Rymdteknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-261797.
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This Master Thesis report presents the mechanical concept and design of a microgravity fluid science experiment that is planned to be launched to the International Space Station in approximately five years. Named AtmoFlow, this experiment aims to study the complex flow phenomena occurring in different planets’ atmosphere by implementing a scaled-down model of a planet-atmosphere system in microgravity. The design introduced here focuses on several of the experiment’s systems: the Turn Table, a rotating system involving a Fluid Cell Assembly, a Thermal Control System and two Rotation Drive Systems. Design methods, main choices and crucial conception steps are presented. Components’ dimensioning and choices are motivated. Models and analyses are derived from the selected design to ensure that the design meets the requirements on microgravity disturbances, structural and rotational characteristics stated during previous project’s phases. The Computer Assisted Design model of the experiment’s final concept and its integration sequence are eventually proposed and discussed.Denna rapport presenterar den mekaniska utformningen av ett mikrogravitationsexperiment som studerar strömningsmekaniska fenomen och som planeras att skickas till den internationella rymdstationen om ungefär fem år. Experimentet heter AtmoFlow och syftar till att studera komplexa flödesfenomen som förekommer i olika planeters atmosfärer genom att implementera en nerskalad modell av en planets atmosfärssystem i mikrogravitation. Utformningen av experimentet som presenteras här fokuserar på flera av experimentets system: rotationsbordet (ett roterande system med en strömningscellhopsättning), ett termiskt reglersystem samt två rotationsdrivsystem. Utformningsmetoder, huvudsakliga val och utformningssteg presenteras. Dimensioneringen av komponenter och deras urval motiveras. Modeller och analyser av den valda konstruktionen har utförts för att säkerställa att den uppfyller kraven på störningar i mikrogravitation, struktur och rotationsegenskaper som specificerats under tidigare faser i utformningen av experimentet. CAD-modellen av den slutliga utformningen av konstruktionen av experimentet presenteras och diskuteras.
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Sobron, Alejandro. "On Subscale Flight Testing : Applications in Aircraft Conceptual Design." Licentiate thesis, Linköpings universitet, Fluida och mekatroniska system, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-152488.
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Downscaled physical models, also referred to as subscale models, have played an essential role in the investigation of the complex physics of flight until the recent disruption of numerical simulation. Despite the fact that improvements in computational methods are slowly pushing experimental techniques towards a secondary role as verification or calibration tools, real-world testing of physical prototypes still provides an unmatched confidence. Physical models are very effective at revealing issues that are sometimes not correctly identified in the virtual domain, and hence can be a valuable complement to other design tools. But traditional wind-tunnel testing cannot always meet all of the requirements of modern aeronautical research and development. It is nowadays too expensive to use these scarce facilities to explore different design iterations during the initial stages of aircraft development, or to experiment with new and immature technologies. Testing of free-flight subscale models, referred to as Subscale Flight Testing (SFT), could offer an affordable and low-risk alternative for complementing conventional techniques with both qualitative and quantitative information. The miniaturisation of mechatronic systems, the advances in rapid-prototyping techniques and power storage, as well as new manufacturing methods, currently enable the development of sophisticated test objects at scales that were impractical some decades ago. Moreover, the recent boom in the commercial drone industry has driven a quick development of specialised electronics and sensors, which offer nowadays surprising capabilities at competitive prices. These recent technological disruptions have significantly altered the cost-benefit function of SFT and it is necessary to re-evaluate its potential in the contemporary aircraft development context. This thesis aims to increase the comprehension and knowledge of the SFT method in order to define a practical framework for its use in aircraft design; focusing on low-cost, short-time solutions that don’t require more than a small organization and few resources. This objective is approached from a theoretical point of view by means of an analysis of the physical and practical limitations of the scaling laws; and from an empirical point of view by means of field experiments aimed at identifying practical needs for equipment, methods, and tools. A low-cost data acquisition system is developed and tested; a novel method for semi-automated flight testing in small airspaces is proposed; a set of tools for analysis and visualisation of flight data is presented; and it is also demonstrated that it is possible to explore and demonstrate new technology using SFT with a very limited amount of economic and human resources. All these, together with a theoretical review and contextualisation, contribute to increasing the comprehension and knowledge of the SFT method in general, and its potential applications in aircraft conceptual design in particular.
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Storfeldt, Joakim. "Design benefits with Additive Manufacturingfrom a convective heat transfer perspective." Thesis, KTH, Flygdynamik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-262005.
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Nowadays manufacturing processes are rapidly developing. Salt-bath dip brazing is a conventional manufacturing method commonly used by Saab AB to fuse aluminium components in a high temperature salt bath. However conventional manufacturing methods have shown some limitations. Additive Manufacturing, or 3D printing, is a newer technology which has become very popular in the industry offering competitive advantages regarding production time and size, and structural complexity of the components among other aspects. In this work, Additive Manufacturing is investigated to assess if the performance of heat sinks can be increased compared to the salt-bath dip brazing method. Geometrical shapes of heat sink-fins were studied by empirical research to compare their characteristics in air-flow, convection and pressure drop. Eight different geometrical shapes have been analyzed using Additive Manufacturing, and the control plate fins was used as a reference for comparison with salt-bath dip brazing. It was found out that the NACA 0010 fins and Square Grid fins geometries gave the best performance with a 63% and 64% decrease in pressure drop per diverted energy compared to the control plate fins, respectively.Numera utvecklas tillverkningsprocesser snabbt. Saltbadslödning är en tillverkningsmetod som vanligen används av Saab AB för att foga aluminiumkomponenter i ett saltbad med hög temperatur. Dock har konventionella tillverkningsmetoder visat vissa begränsningar. Additiv Tillverkning eller 3D printing är andra tekniker som har blivit mycket populära i industrin på grund av dess många fördelar med avseende på produktionstid, storlek och bland andra aspekter strukturkomplexitet. I det här arbetet undersöks det om Additiv Tillverkning kan användas för att öka prestanda på kylflänsar jämfört med Saltbadslödning. Geometriska former av kylflänsar studerades genom empirisk forskning för att jämföra deras egenskaper i luftflöde, konvektion och tryckfall. Åtta olika geometriska former skapade utifrån Additiv Tillverkning har studerats och jämförts med en kontroll som representerar saltbadslödning. Det upptäcktes att NACA 0010-fenor och kvadratiska rutnäts-geometrier gav den bästa prestandan med en minskning i tryckfall på 63% respektive 64% per avledd energi jämfört med kontrollfenorna.
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Díaz, Vázquez Guillermo. "Case Data Analysis Tool for PowerFLOW." Thesis, KTH, Flygdynamik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-262008.
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The field of computational fluid dynamics (CFD) is exponentially growing in terms of performance, robustness, and applications. The expansion of CFD also means more users and more simulations, which translates into more human errors and mistakes in the simulation set up. Because the simulation set up should be the correct in order to accurately reproduce the desired phenomenon, such errors must be mitigated in order to increase the reliability and robustness of the simulations. In this project a tool has been developed to tackle this issue, within the CFD software SIMULIA PowerFLOW. The tool extracts and analyzes the data of the cases before simulation, reporting the results to the user for error detection. The present work aims to present the implementation, the application and the benefits of the designed tool.Strömningsmekaniska beräkningar (CFD) området växer exponentiellt med avseende på prestanda, robusthet och tillämpningar. Expansionen av CFD bidrar även till er användare och simuleringar, vilket i sin tur leder till er mänskliga fel och misstag i uppsättningen av simuleringar. Eftersom simuleringsuppsättningen behöver vara korrekt för att återskapa önskade fenomen, behöver sådana fel undvikas för att kunna öka simuleringens tillförlitlighet och robusthet. Med avseende på detta utvecklades ett verktyg i CFD mjukvaran SIMULIA PowerFLOW. Verktyget extraherar och analyserar inställningarna före simulering och rapporterar resultaten till användaren för feldetektering. Det här arbetet redogör för utvecklingen, tillämpningen och fördelarna med framställda verktyget.
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Pavlovic, Boban. "Dynamic Performance Analysis of a Fighter Jet with Nonlinear Dynamic Inversion." Thesis, KTH, Flygdynamik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-262009.
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A modern view of aircraft performance analysis, is to quantify aircraft manoeuvrability with agility metrics. There are several different agility metrics, which can be seen as indexing of the aircraft agility performance. The quantified unit is the time it takes for the aircraft to perform a specific manoeuvre relevant to a given agility metric. In this thesis, estimations are done of two agility metrics, the CCT (Combat Cycle Time) and the T90 (Time to capture 90◦ bank angle) for the F-18 HARV aircraft.Estimations of the agility metrics were obtained by simulating a six-degree-of-freedom aircraft model of the F-18 HARV aircraft performing the specific manoeuvres. To control the aircraft model during the simulation a control sys-tem was developed based on the NDI (Nonlinear Dynamic Inversion) method with time scale separation assumption. The method uses the feedback from the controlsystem for linearizing the aircraft system, which results in that simple linear controllers can be applied to the nonlinear aircraft model.In this case simple proportional controllers were implemented and in the case of estimating the T90 agility metric additional gain scheduling as functions of altitude and Mach number was required to extract maximum performance. Although the control system was developed for these two specific agility metrics, results indicates that the NDI method provides an effective way to implement controllers for complex systems, especially when considering a high nonlinear flight regime.
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Wehtje, Ernst. "Development of miniaturized fill and drain system for propellant tanks on small satellites." Thesis, KTH, Rymdteknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-262027.
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Under de senaste åren har rymdindustrin förändrats markant av bland annat inflödet av privat finansiering och tillgängligheten av ny teknologi, vilket har resulterat i att mindre och billigare satelliter finns på marknaden. GomSpace Sweden, som är en del av GomSpace Group, är en aktör på denna marknad och utvecklar framdrivningssystem för mindre satelliter, så kallade CubeSats. En av deras miniatyriserade produkter är ett framdrivningssystem av kall gas, som passar för 3-unit CubeSats. Med dagens design kan bränsletanken fyllas genom en ingångsport men endast tömmas genom munstyckena, vilket skapar flertalet problem. Detta arbete avser att utveckla en lösning på dessa problem och skapa ett fullständigt fyllnings- och tömningssystem för GomSpace produkt. En konceptuell lösning av ett fyllnings- och tömningsverktyg utvecklades, för att sedan designas och slutligen tillverkas. Verktyget testades, och resultaten uppfyllde de initialt ställda kravspecifikationerna. Efter fler utförda tester uppstod möjligheter till förbättringar vilket ledde till att en andra digital version av verktyget utvecklades. Ett förslag till en mergenerell lösning för fyllnings- och tömningssystem utvecklades också, vilket kan användas som en modul i framtida utvecklingsprocesser av små framdrivningssystem. Sammanfattningsvis visar detta arbete en lösning på problemet med fyllnings- och tömningssystemet av det nuvarande framdrivningssystemet för 3-unit CubeSats. Ett verktyg både tillverkades och testades med framgång. En förbättrad version av verktyget, som minskar riskerna för skador och slitage samt förenklar användningen, skapades som en digital modell. Slutligen, designades en generell lösning för fyllnings- och tömningssystem, vilket skulle kunna användas i flertalet av GomSpace’ framtida produkter och därmed minska bådekostnader och tid för produktutveckling.During recent years, private funding and new technology have boosted a change of the space industry, resulting in smaller and cheaper satellites being available on the market. GomSpace Sweden, part of GomSpace Group, is located in this market and develops propulsion systems for small satellites, so called, CubeSats. One of these highly miniaturized and efficient products is the cold gas propulsion system, suitable for 3-unit CubeSats. Due to the current design, the propellant tank of the system can be filled through a port but only drained through the thrusters, which causes several issues. This thesis concerns the development of a solution to these issues and creating a complete fill and drain system. A conceptual solution for a fill and drain tool was created and later designed as well as manufactured. The tool was tested and all initial requirements were successfully verified. However, through testing the functionality of the tool, several areas of improvement were found. A second version of the tool was digitally designed to meet these improvements. Also, a proposal of a more general fill and drain solution was digitally designed, which could be realized as a module in future development processes, including a fill and drain tank interface, fill and drain tool and a fill and drain procedure. In conclusion of the thesis, a solution to the problem with the current design of the propulsion system was successfully developed and tested. An improved version of the solution was designed, which decreases the risk of damage to the propulsion system and simplifies the usage. Finally, a design of a general fill and drain system was created, which could possibly span over several future GomSpace products and lowering both the cost and time of development.
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Cirillo, Giovanni. "Space Surveillance and Tracking Tool: Implementation and Test of New Methods." Thesis, KTH, Rymdteknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-262030.
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In March 2019 the number of artificial objects bigger than 1 mm in orbit around the Earth is estimated to be more than 170 millions. Only a small fraction of them (0.03%) is catalogued. An impact of an operational satellite with one of these debris can damage the satellite and undermine its mission. So it is important to catalogue as many objects as possible in order to reduce the risk of a collisions. This is done by using the software tool Space Object Observations and Kalman Filtering (SPOOK), developed in Airbus Defence and Space in Friedrichshafen. The goal of this Master Thesis was to create newfunctionalities to this tool and improve the existing ones. In particular three main goals have been accomplished: • a new model for the lighting ratio has been built to take into account the occultation of the Sun due to a covering body (for example the Earth or the Moon) and itsinfluence on the solar radiation pressure, necessary to have a good model for orbit propagation; • a tracklet building algorithm has been built to distinguish different tracklets (consecutive observations of the same object along its orbit) as a starting point for the association of different measurements belonging to the same object at distant epochs, necessary to update a catalogue of space objects; • a model to take into account the process noise has been improved giving some suggestion on how to tune the different parameters for different kinds of orbit.I mars 2019 uppgick antalet konstgjorda föremål större än 1 mm i omloppsbana runt jorden till över 170 miljoner. Av dessa är endast en mycket liten andel (0.03%) katalogiserade. En kollision mellan en operativ satellit och ett annat föremål i bana kan helt eller delvis förstöra satelliten. För att reducera risken för kollisioner är det därför viktigt att katalogisera så många föremål som möjligt. Detta görs genom att använda programvaran "Space Object Observations and Kalman Filtering" (SPOOK), som utvecklats av företaget Airbus Defence and Space i Friedrichshafen, Tyskland. Målet med detta examensarbete var att skapa nya funktioner i programvara samt att förbättra de befintliga funktionerna. Tre huvudmål har uppnåtts: • En ny modell för ljusförhållandet har skapats för att ta hänsyn till ocklutationen av solen på grund av en täckande kropp (till exempel jorden eller månen) och dess påverkan på solstrålningstrycket på rymdfarkosten, vilket är nödvändigt för att ha en bra modell för hur omloppsbanan fortplantas • En algoritm för s.k. tracklets, flera observationer av samma föremål längs dess omlopp, har skapats i syfte att skilja mellan olika tracklets som utgångspunkt för bestämma vilka mätningar som tillhör samma föremål vid avlägsna epoker. Detta är nödvändigt för att korrekt kunna uppdatera katalogen över rymdföremål. • Modellen för att ta hänsyn till processbruset har förbättrats och förslag ges om hur man ställer in olika parametrar för olika slags omloppsbanor.
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Charpigny, Noé. "An Executable System Model for Behavioural Analyses of the LISA Mission." Thesis, KTH, Rymdteknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-262033.
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This master thesis report presents the modelling process of key elements of the Laser Interferometer Space Antenna mission (LISA mission) in a Modelbased systems engineering (MBSE) approach with SysML (Systems Modeling Language). The model implements a selected set of functions of the mission through executable graphical representations, called diagrams. It is shown how such diagrams can benefit the mission, by comparing this mean of information exchange to the traditional text- based systems engineering. The model represents the mission structure and behaviour through a system of nested layers. The deeper the layer is, the more it gives details on a system part. Each layer can be seen from different point of views, either focusing on the structure, the behaviour, or the performance of related system part.I detta examensarbete presenteras modelleringsprocesserna av nyckelelementen i rymduppdraget LISA (Laser Interferometer Space Antenna) inom modellbaserad systemteknik (Model-based systems engineering MBSE) med SysML (Systems Modeling Language). Modellen implementerar en vald uppsättning av uppdragets funktioner genom exekverbara grafiska representationer, kallade diagram. Jag visar hur dessa exekverbara representationer kan vara fördelaktiga för rymduppdraget genom att jämföra detta informationsutbyte med traditionella text-baserade modelleringsprocesser. Modellen representerar hur uppdraget är strukturerat och hur den beter sig i ett system av lager. Ju djupare ett lager är desto mer detaljerad insyn ger det i olika delar av systemet. Varje lager kan ses från olika perspektiv, antingen med fokus på strukturen, på beteendet eller på prestationen av de relaterade systemdelarna.
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Berhouni, Ilyès. "Flow transition prediction approaches evaluated on a single-aisle type aircraft." Thesis, KTH, Flygdynamik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-262040.
Full textAbstract:
Nowadays, as the demand for fuel efficiency is increasing and the manufacturing techniques improved to allow the design of laminar wings, the laminar concepts are being revived and studied, and seen as one of the most promising techniques to reduce skin friction and hence the overall drag of the airframe. In order to predict the kind of benefits that could be obtained from such concepts, computational fluid dynamics (CFD) computations can now be carried out but it is necessary to be able to predict flow transition from laminar to turbulent around the lifting surfaces of the aircraft, such as the wing and the horizontal tail plane. Such capability has been developed in the last years by the French Aerospace Laboratory (ONERA) with their CFD code elsA, and by the German Aerospace Center (DLR) with their CFD code Tau. These two codes are widely used in Airbus in their CFD campaigns, and this study aims to assess the capability of the different approaches to predict transition and the benefits from laminar flow in the overall drag. The methods used, the limitations and the suggestions for further improvement of the codes will be detailed in this paper.Nuförtiden, eftersom efterfrågan på bränsleeffektivitet ökar och tillverkningstekniker förbättrats för att tillåta utformningen av laminära vingar, de laminära begrepp att återupplivas och studeras och ses som en av de mest lovande teknikerna för att minska ytfriktionen och därmed den totala motståndet hos skrovet. För att förutsäga den typ av fördelar som kan erhållas från sådana begrepp, computational fluid dynamics (CFD) beräkningar kan nu utföras men det är nödvändigt att kunna förutse övergångsflöde från laminär till turbulent runt lyftytorna hos flygplanet , såsom kanterna och det horisontella stjärtplan. En sådan förmåga har utvecklats under de senaste åren av den franskaAerospace Laboratory (ONERA) med sin CFD kod Elsa och av den tyska Aerospace Center (DLR) med sin CFD kod Tau. Dessa två koder används allmänt i Airbus i deras CFD kampanjer och denna studie syftar till att bedöma förmågan hos de olika metoder för att förutsäga övergång och fördelarna med laminärt flöde i den totala drag. De metoder som används, de begränsningar och de förslag till ytterligare förbättring av de koder kommer att beskrivas i detalj i detta dokument.
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Tneh, Shao Heung. "Feasibility Study on Implementing IVF Hardware to Achieve Human Reproduction in Space." Thesis, Luleå tekniska universitet, Institutionen för system- och rymdteknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-76571.
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