Thèses : « Space Nozzle »

1

Bae, Yoon-Yeong. « Performance of an aero-space plane propulsion nozzle / ». Full-text version available from OU Domain via ProQuest Digital Dissertations, 1989.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

2

Glesner, Colin Christopher. « Development of Magnetic Nozzle Simulations for Space Propulsion Applications ». Thesis, Virginia Tech, 2017. http://hdl.handle.net/10919/74947.

Texte intégral

Résumé :

A means of space propulsion using the channeling of plasma by a divergent magnetic field, referred to as a magnetic nozzle has been explored by a number of research groups. This research develops the capability to apply the high order accurate Runge-Kutta discontinuous Galerkin numerical method to the simulation of magnetic nozzles. The resistive magnetohydrodynamic model of plasma behavior is developed for these simulations. To facilitate this work, several modeling capabilities are developed, including the implementation of appropriate inflow and far-field boundary conditions, the application of a technique for correcting errors that develop in the divergence of the magnetic field, and a split formulation for the magnetic field between the applied and the perturbed component. This model is then applied to perform a scaling study of the performance of magnetic nozzles over a range of Bk and Rm. In addition, the effect of the choice of simulation domain size is investigated. Finally, recommendations for future work are made.
Master of Science

Styles APA, Harvard, Vancouver, ISO, etc.

3

Meiss, Jan-Hendrik. « Numerical investigation of nozzle base flow interaction of a generic space vehicle ». Aachen Shaker, 2009. http://d-nb.info/99777827X/04.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

4

Bradford, John Edward. « A technique for rapid prediction of aftbody nozzle performance for hypersonic launch vehicle design ». Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/12896.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

5

Squire, Daniel E. « Flow study of the nozzle region of the space shuttle solid rocket motor ». Thesis, This resource online, 1988. http://scholar.lib.vt.edu/theses/available/etd-04122010-083741/.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

6

Vidakovic, Steven Slavko. « Fluid dynamic means of varying the thrust vector from an axisymmetric nozzle / ». Title page, summary and contents only, 1995. http://web4.library.adelaide.edu.au/theses/09PH/09phv648.pdf.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

7

Meiß, Jan H. [Verfasser]. « Numerical Investigation of Nozzle-Base-Flow Interaction of a Generic Space Vehicle / Jan H Meiß ». Aachen : Shaker, 2009. http://d-nb.info/1159836361/34.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

8

Glassman, Brian. « Spray Cooling for Land, Sea, Air and Space Based Applications, A Fluid Managment System for Multiple Nozzle Spray Cooling and a Guide to High Heat Flux Heater Design ». Master's thesis, University of Central Florida, 2005. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3521.

Texte intégral

Résumé :

This thesis is divided into four distinct chapters all linked by the topic of spray cooling. Chapter one gives a detailed categorization of future and current spray cooling applications, and reviews the major advantages and disadvantages that spray cooling has over other high heat flux cooling techniques. Chapter two outlines the developmental goals of spray cooling, which are to increase the output of a current system and to enable new technologies to be technically feasible. Furthermore, this chapter outlines in detail the impact that land, air, sea, and space environments have on the cooling system and what technologies could be enabled in each environment with the aid of spray cooling. In particular, the heat exchanger, condenser and radiator are analyzed in their corresponding environments. Chapter three presents an experimental investigation of a fluid management system for a large area multiple nozzle spray cooler. A fluid management or suction system was used to control the liquid film layer thickness needed for effective heat transfer. An array of sixteen pressure atomized spray nozzles along with an imbedded fluid suction system was constructed. Two surfaces were spray tested one being a clear grooved Plexiglas plate used for visualization and the other being a bottom heated grooved 4.5 x 4.5 cm2 copper plate used to determine the heat flux. The suction system utilized an array of thin copper tubes to extract excess liquid from the cooled surface. Pure water was ejected from two spray nozzle configurations at flow rates of 0.7 L/min to 1 L/min per nozzle. It was found that the fluid management system provided fluid removal efficiencies of 98% with a 4-nozzle array, and 90% with the full 16-nozzle array for the downward spraying orientation. The corresponding heat fluxes for the 16 nozzle configuration were found with and without the aid of the fluid management system. It was found that the fluid management system increased heat fluxes on the average of 30 W/cm2 at similar values of superheat. Unfortunately, the effectiveness of this array at removing heat at full levels of suction is approximately 50% & 40% of a single nozzle at respective 10[degrees]C & 15[degrees]C values of superheat. The heat transfer data more closely resembled convective pooling boiling. Thus, it was concluded that the poor heat transfer was due to flooding occurring which made the heat transfer mechanism mainly forced convective boiling and not spray cooling. Finally, Chapter four gives a detailed guide for the design and construction of a high heat flux heater for experimental uses where accurate measurements of surface temperatures and heat fluxes are extremely important. The heater designs presented allow for different testing applications; however, an emphasis is placed on heaters designed for use with spray cooling.
M.S.
Department of Mechanical, Materials and Aerospace Engineering;
Engineering and Computer Science
Mechanical Engineering

Styles APA, Harvard, Vancouver, ISO, etc.

9

Ramirez, Carlos. « Meso-machining of miniature space system components ». To access this resource online via ProQuest Dissertations and Theses @ UTEP, 2007. http://0-proquest.umi.com.lib.utep.edu/login?COPT=REJTPTU0YmImSU5UPTAmVkVSPTI=&clientId=2515.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

10

Bulut, Jane. « Design and CFD analysis of the demonstrator aerospike engine for a small satellite launcher application ». Master's thesis, Alma Mater Studiorum - Università di Bologna, 2020.

Trouver le texte intégral

Résumé :

Starting with a brief overview of thrust generation for launchers, this study focuses on the design process of the demonstrator aerospike engine, DEMOP-1, of the Pangea Aerospace's commercial grade engine and its flow field analysis. The primary goal of the study is to obtain the plug nozzle design delivers 30 kN thrust using cryogenic liquid oxygen (LOX) as the oxidizer and cryogenic liquid methane (LCH4) as the fuel, with the mixture ratio of 3.4. Design parameters considered as 30 bar of combustion chamber pressure (Po) and expansion ratio as 15 for an optimum expanded nozzle. On the basis of decided design characteristics, Angelino's method is used to design the nozzle contour through MATLAB. The flow field over the aerospike analyzed using commercial CFD program FLUENT for sea level, optimum expansion and vacuum conditions. Flow simulations are carried out for air (specific heat ratio, gamma= 1.4), and afterwards based on the obtained thrust values at each altitude for air, expected thrust values for the real propellant, LOX/LCH4 (specific heat ratio, gamma = 1.1664), are calculated. Finally, the study is concluded with the comparison of trend in thrust and specific impulse for conventional bell nozzle and aerospike. For the conventional bell engine the values obtained in commercial computational simulation of chemical rocket propulsion and combustion software RPA for bell nozzle with same characteristics with aerospike, Po = 30 bar and expansion ratio = 15, are taken as reference for sea level, optimum expansion level and vacuum condition performance. Due to its ability to adopt the altitude, aerospike delivers higher performance at the low altitudes with respect to the conventional bell nozzle which has the same expansion ratio and combustion chamber pressure. Last in order but not in importance, after obtaining the flow field on plug of the aerospike, the shock wave impingement on the nozzle surface at sea level has been investigated.

Styles APA, Harvard, Vancouver, ISO, etc.

11

Vialis, Théo. « Développement d’un propulseur plasma à résonance cyclotron électronique pour les satellites ». Thesis, Sorbonne université, 2018. http://www.theses.fr/2018SORUS344.

Texte intégral

Résumé :

Ce travail de thèse porte sur le propulseur électrique de type ECR (résonance cyclotron électronique) développé à l’ONERA. Ce propulseur quasi-neutre, qui utilise une tuyère magnétique pour accélérer le plasma, produit une poussée d’environ 1 mN pour des puissances inférieures à 50 W. Dans cette thèse, on se propose de développer et d’optimiser les diagnostics de mesure des performances du propulseur ECR, d’identifier les paramètres expérimentaux pouvant influencer les performances et d’améliorer la compréhension des phénomènes physiques ayant lieu dans le propulseur. Ces objectifs ont pour finalité l’amélioration des performances. Pour répondre à ces objectifs, plusieurs prototypes à aimant permanent ont été développés, et une balance permettant de mesurer directement la poussée a été modifiée pour caractériser le propulseur. Différentes études paramétriques ont été conduites, qui ont montré que les performances dépendaient directement du rapport entre le débit de xénon et la puissance micro-onde injectée. Il a également été observé que la longueur du conducteur externe de la source plasma et la pression ambiante ont une influence significative sur le niveau de performance. Après optimisation de la géométrie, un rendement total supérieur à 12 % a été obtenu. Des mesures séparées de la poussée thermique et magnétique ont permis de montrer que la composante magnétique était la contribution principale de la poussée dans tous les cas testés. Un code PIC 1D-3V a été utilisé pour simuler le comportement du propulseur, et a permis de reproduire le chauffage des électrons par résonance et l’accélération des espèces chargées dans la tuyère. L’ensemble des travaux ont mis en avant le rôle des composantes parallèle et perpendiculaire de la pression électronique
Electric propulsion is an alternative technology to the chemical propulsion that enables reducing propellant consumption for satellites. ONERA is developing an electric ECR thruster with a thrust around 1 mN and an electric power less than 50 W. The thruster creates a plasma by electron cyclotron resonance and accelerates it through a magnetic nozzle. In this thesis work, an optimization of the measurement diagnostics is done. The work also aims at identifying the important parameters for the performances of the thruster and at improving the understanding of underlying physics, in order to increase the thruster efficiency. Several prototypes have been developed and a thrust stand that can directly measure the thrust has been modified. Some parametric studies have been led and have shown that the thruster performance strongly depends on xenon mass-flow rate to microwave power ratio. It has also shown that the external conductor of the plasma source and the ambient pressure have a significant influence on the performances. Following a geometric optimization, a maximum total efficiency of more than 12% has been obtained. Separate measurements of the magnetic and thermal thrust have shown that the magnetic thrust is the main component of the total thrust. A 1D-3V PIC code has been used to simulate the behavior of the thruster. The analysis of the results has shown that the ECR heating and particle acceleration in the magnetic nozzle could be properly computed. The role of the parallel and perpendicular component of electron pressure has been evidenced by this work

Styles APA, Harvard, Vancouver, ISO, etc.

12

Bolgar, Istvan [Verfasser], Christian J. [Akademischer Betreuer] Kähler, Christian J. [Gutachter] Kähler et Rolf [Gutachter] Radespiel. « On the performance increase of future space launchers : Investigations of buffeting, its reduction via passive flow control, and the Dual-Bell nozzle concept at trans- and supersonic flight conditions / Istvan Bolgar ; Gutachter : Christian J. Kähler, Rolf Radespiel ; Akademischer Betreuer : Christian J. Kähler ; Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik ». Neubiberg : Universitätsbibliothek der Universität der Bundeswehr München, 2019. http://d-nb.info/1222682982/34.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

13

Bolgar, Istvan [Verfasser], Christian J. [Akademischer Betreuer] Kähler, Christian J. Gutachter] Kähler et Rolf [Gutachter] [Radespiel. « On the performance increase of future space launchers : Investigations of buffeting, its reduction via passive flow control, and the Dual-Bell nozzle concept at trans- and supersonic flight conditions / Istvan Bolgar ; Gutachter : Christian J. Kähler, Rolf Radespiel ; Akademischer Betreuer : Christian J. Kähler ; Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik ». Neubiberg : Universitätsbibliothek der Universität der Bundeswehr München, 2019. http://nbn-resolving.de/urn:nbn:de:bvb:706-6871.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

14

Coltrin, Ian S. « The Influence of Nozzle Spacing and Diameter on the Acoustic Emissions of Closely Spaced Supersonic Jet Arrays ». BYU ScholarsArchive, 2012. https://scholarsarchive.byu.edu/etd/2935.

Texte intégral

Résumé :

The acoustic emissions from supersonic jets represent an area of significant research needs; not only in the field of aero-acoustics, but in industry as well where high pressure let down processes have been known to cause acoustically induced vibrations. A common method to reduce the acoustic emissions of such processes involves dividing the single larger supersonic flow into several smaller ones. Though this is common practice, there is not yet a current model which describes the reduction of acoustic emissions from an array of smaller supersonic jets. Current research which studies supersonic jet arrays are mainly focused on the effects of screech. Though screech is important, due to its high amplitude acoustic pressure, this research focuses on the overall acoustic emissions radiated from supersonic jet arrays which can cause severe acoustic loadings. This research investigated the acoustic emissions and shock formations from several eight by eight arrays of axisymmetric jet experimentally. The array nozzle diameters investigated ranged from 1/8 inch to 1/4 inch and the spacing over diameter ratio ranged from 1.44 to 3. The net pressure ratios investigated ranged from 2 to 24. Results revealed a strong correlation between the acoustic emissions and the shock formations of the flow. Up until a critical net pressure ratio, the overall sound pressure levels were comparable to that of a single jet within an array. At net pressure ratios beyond the critical the overall sound pressure levels transitioned to higher decibel levels; equivalent to a single jet with an equivalent exit area of an entire array. Also, the characteristic acoustic frequency emitted from a nozzle array remained ultrasonic (above 20 kHz) at lower net pressure ratios and then shifted to audible levels (between 20 Hz to 20 kHz) at net pressure ratios beyond the critical. Also, before the critical net pressure ratio the shock cells from the jets within the array remained unmerged, but at net pressure ratios beyond the critical the shock cells merged and formed lattices of weak oblique shocks at first and then strong oblique shocks as the net pressure ratio continued to increase. The critical net pressure ratio was investigated by non-dimensional analysis. The non-dimensional analysis revealed that the critical net pressure ratio was a strong linear function of the spacing over diameter ratio. A linear model was derived which is able to predict the critical net pressure ratio, and in turn, predict a critical shift in the acoustic emissions of a nozzle array.

Styles APA, Harvard, Vancouver, ISO, etc.

15

Wahlström, Dennis. « Probabilistic Multidisciplinary Design Optimization on a high-pressure sandwich wall in a rocket engine application ». Thesis, Umeå universitet, Institutionen för fysik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-138480.

Texte intégral

Résumé :

A need to find better achievement has always been required in the space industrythrough time. Advanced technologies are provided to accomplish goals for humanityfor space explorer and space missions, to apprehend answers and widen knowledges. These are the goals of improvement, and in this thesis, is to strive and demandto understand and improve the mass of a space nozzle, utilized in an upperstage of space mission, with an expander cycle engine. The study is carried out by creating design of experiment using Latin HypercubeSampling (LHS) with a consideration to number of design and simulation expense.A surrogate model based optimization with Multidisciplinary Design Optimization(MDO) method for two different approaches, Analytical Target Cascading (ATC) and Multidisciplinary Feasible (MDF) are used for comparison and emend the conclusion. In the optimization, three different limitations are being investigated, designspace limit, industrial limit and industrial limit with tolerance. Optimized results have shown an incompatibility between two optimization approaches, ATC and MDF which are expected to be similar, but for the two limitations, design space limit and industrial limit appear to be less agreeable. The ATC formalist in this case dictates by the main objective, where the children/subproblems only focus to find a solution that satisfies the main objective and its constraint. For the MDF, the main objective function is described as a single function and solved subject to all the constraints. Furthermore, the problem is not divided into subproblems as in the ATC. Surrogate model based optimization, its solution influences by the accuracy ofthe model, and this is being investigated with another DoE. A DoE of the full factorial analysis is created and selected to study in a region near the optimal solution.In such region, the result has evidently shown to be quite accurate for almost allthe surrogate models, except for max temperature, damage and strain at the hottestregion, with the largest common impact on inner wall thickness of the space nozzle. Results of the new structure of the space nozzle have shown an improvement of mass by ≈ 50%, ≈ 15% and ≈ -4%, for the three different limitations, design spacelimit, industrial limit and industrial limit with tolerance, relative to a reference value,and ≈ 10%, ≈ 35% and ≈ 25% cheaper to manufacture accordingly to the defined producibility model.

Styles APA, Harvard, Vancouver, ISO, etc.

16

Ebersohn, Frans 1987. « Gas Kinetic Study of Magnetic Field Effects on Plasma Plumes ». Thesis, 2012. http://hdl.handle.net/1969.1/148434.

Texte intégral

Résumé :

Plasma flow physics in magnetic nozzles must be clearly understood for optimal design of plasma propulsion devices. Toward that end, in this thesis we: i) perform an extensive literature survey of magnetic nozzle physics, ii) assess the validity of magnetohydrodynamics for studying magnetic nozzle physics, and iii) illustrate the effects of the Hall term in simple flows as well as in magnetic nozzle configurations through numerical experiments with the Magneto-Gas Kinetic Method (MGKM). The crucial steps necessary for thrust generation in magnetic nozzles are energy conversion, plasma detachment, and momentum transfer. These three physical phenomena must be understood to optimize magnetic nozzle design. The operating dimensionless parameter ranges of six prominent experiments are considered and the corresponding mechanisms are discussed. An order of magnitude analysis of the governing equations reveal: i) most magnetic nozzles under consideration operate at the edge of the continuum regime rendering continuum-based description and computation valid; ii) in the context of MHD framework, the generalized Ohm’s law must be used to capture all of the relevant physics. This work also continues the development of the Magneto Gas Kinetic Method (MGKM) computational tool. Validation of the solver is performed in shock-tube and Hartmann channel flows in the Hall physics regime. Comparison with theory and available data is made whenever possible. Novel numerical experiments of magnetic nozzle plasma jets in the Hall regime are performed, confirming the theoretically predicted azimuthal rotation of the plasma jet due to Hall physics. The primary conclusion from this work is that the addition of the Hall effect generates helical structures in magnetic nozzle plasma flows. Preliminary results are encouraging for future magnetic nozzle studies and further challenges are identified.

Styles APA, Harvard, Vancouver, ISO, etc.

17

Hou, Shuhai. « Investigation of the interaction mechanisms between closely spaced sprays from micro-hole nozzles ». 2005. https://scholarworks.umass.edu/dissertations/AAI3163674.

Texte intégral

Résumé :

A computer code for the dispersed liquid phase is constructed in an Eulerian-Fluid-Lagrangian-Particle spray simulation program. Various sub-models for spray droplets, which include droplet injection, droplet tracking, inter-phase momentum coupling, droplet breakup, droplet collision and droplet turbulent dispersion, are implemented. An adaptive meshing method for collision calculation in sprays is presented. The adaptive mesh is shown to be capable of producing higher spatial resolution than the conventional mesh. At the same time the mesh can maintain an adequate sample of computational parcels in each cell to ensure statistically accurate results. The random orientation of the mesh avoids any artifacts associated with a fixed mesh, leading to reduced grid dependency of collision calculation. Satellite droplet formation resulting from ligament stretching during collision can significantly reduce the spray drop size. An existing satellite droplet formation model has been improved to reflect the experimental findings that the satellite droplets are much smaller than the parent droplets. The improved model is shown to produce better agreement with the experimental data. Micro-hole nozzles of various configurations are simulated and the results are discussed. The possible interaction mechanisms between the closely spaced sprays are identified and their relative significance is assessed. It is found that the collisions between droplets from different holes are largely responsible for the droplet size variation with different nozzle configurations. The results obtained in this work are very important in facilitating the design and manufacturing of the micro-hole nozzles.

Styles APA, Harvard, Vancouver, ISO, etc.

Thèses sur le sujet « Space Nozzle »

Créez une référence correcte selon les styles APA, MLA, Chicago, Harvard et plusieurs autres