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Kuttelwascher, Pavel. "Obslužný software pro CCD kameru používanou pro elektroluminiscenci." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2013. http://www.nusl.cz/ntk/nusl-220232.
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This thesis studies the optimization of diagnosis defects of the photovoltaic cells in the darkroom by the help of new operating software for the used CCD camera. First the present situation and the possible solutions are analyzed. Then the attention is paid to the theory of light-sensitive CCD sensors, their construction, their principles of operation and the theory of scanning images. The thesis also focuses on the analysis of the function of the operating libraries which were provided by the equipment producer. The key part is the development of the application for the camera G2-3200 of the "Moravske pristroje" company which significantly accelerates the work with the camera in the darkroom.
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Kjellsson, My, and Malin Larsson. "3D CAD METHODOLOGY PRESTUDY." Thesis, Örebro universitet, Institutionen för naturvetenskap och teknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-69781.
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The report describes a prestudy project for Epiroc Rock Drills AB at the department PLM Solutions. The company consists of a number of divisions thatall work with or are affected by CAD models. PLM Solutions has long seen a need for a common methodologybut due to the priorities of other projects this has been delayed. The purpose of the prestudy was to provide a mapping of the CAD methodology at the company today and also investigate the need for methodology. Based on the mapping, a recommendation was given ofhow PLM Solutions shouldproceed with a major methodology project. The recommendation wastocreate a common overall CAD methodology and take advantage of the already existing methodsin the organization. As the problem was treated as a prestudy, the method of a prestudy model is also the case. The model is general and adapted to fit this particular project. The approach deals with the phases: start-up, background analysis and solutions. The background analysis examines the current situation analysis using models for interviewing techniques. A larger part of the basis for the prestudy rests on interviews with stakeholders. The result is presented based on the same phases that the method consists of. The result is a mapping of the methodology and needs of the divisions, this is also visualized using a SWOT analysis. The results arealso the recommendation and requirements based on the interviews and business case. Continued work should as a suggestion include several more interviews, collecting more material from around the divisions, more detailed calculations and a focus on the departments that are affected by the models.<br>Rapporten avhandlar ett förstudieprojekt för företaget EpirocRock Drills AB på avdelningen PLM Solutions. Företaget består av ett antal divisioner som alla arbetar med eller påverkas av CAD-modeller. PLM Solutions har länge sett ett behov av en gemensam metodik men på grund av prioriteringar av andra projekt har detta dröjt. Förstudiens syfte var att ta fram en kartläggning av den CAD-metodik som finns på företaget idag samt även se vilket behov av metodik som förekommer. Utifrån kartläggningen skulle en rekommendation ges i fråga om hur PLM Solutions skulle gå vidare vid ett större metodikprojekt. Rekommendationen var att skapa en övergripande gemensam CAD metodik och dra nytta av de redan existerande metoderna runt om i verksamheten. I och med att problemet behandlades som en förstudie utgörs också metoden av en förstudiemodell. Modellen är generell och anpassad för att passa just detta projekt. Tillvägagångssättet behandlar faserna uppstart, bakgrundsanalys och lösningar. I bakgrundsanalysen behandlas nulägesanalysen med hjälp av modeller för intervjuteknik. En större del av det underlag förstudien utgörs av, bygger på intervjuer med intressenter. Resultatet presenteras utifrån samma faser som metoden utgörs av. Resultatet består av en kartläggning av den metodik och behov som finns bland divisionerna, detta visualiseras också med hjälp av en SWOT-analys. Resultatet utgörs också av rekommendationen och kravspecifikationen som baseras på de intervjuer som utförts samt affärsfallet. Fortsatt arbetebör förslagsvis inkludera flerintervjuer, samla in mer material fråndivisionerna, mer utförliga beräkningar och ett större fokus på de avdelningar som påverkas av modellerna.
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Ramaswamy, Sunil. "Selection of best drilling, completion and stimulation method for coalbed methane reservoirs." Texas A&M University, 2007. http://hdl.handle.net/1969.1/85835.
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Over the past three decades, coalbed methane (CBM) has moved from a mining
hazard and novel unconventional resource to an important fossil fuel that
accounts for approximately 10% of the U.S. natural gas production and reserves.
The expansion of this industry required development of different drilling,
completion and stimulation practices for CBM in specific North American basins,
owing to the complex combinations of geologic settings and reservoir parameters
encountered. These challenges led to many technology advances and to
development of CBM drilling, completion and stimulation technology for specific
geologic settings.
The objectives of this study were to (1) determine which geologic parameters
affect CBM drilling, completion and stimulation decisions, (2) identify to the
engineering best practices for specific geologic settings, and (3) present these findings in decision charts or advisory systems that could be applied by industry
professionals.
To determine best drilling, completion and stimulation practices for CBM
reservoirs, I reviewed literature and solicited opinions of industry experts through
responses to a questionnaire. I identified thirteen geologic parameters (and their
ranges of values) that are assessed when selecting CBM drilling, completion and
stimulating applications. These are coal thickness, number of seams, areal
extent, dip, depth, rank, gas content, formation pressure, permeability, water
saturation, and compressive strength, as well as the vertical distribution of coal
beds and distance from coal reservoirs to fracture barriers or aquifers. Next, I
identified the optimum CBM drilling, completion and stimulating practices for
specific combinations of these geologic parameters. The engineering best
practices identified in this project may be applied to new or existing fields, to
optimize gas reserves and project economics.
I identified the best engineering practices for the different CBM basins in N.A and
combined these results in the form of two decision charts that engineers may use
to select best drilling and completion practices, as well as the optimal stimulation
methods and fluids for specific geologic settings. The decision charts are
presented in a Visual Basic Application software program to facilitate their use by
engineers.
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Andrews, Peter T. J. "Design reuse in a CAD environment." Thesis, Brunel University, 1999. http://bura.brunel.ac.uk/handle/2438/5086.
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For many companies, design related information mainly exists as rooms of paper-based archives, typically in the form of manufacturing drawings and technical specifications. This 'static' information cannot be easily reused. The work presented in this thesis proposes a methodology to ease this problem. It defines and implements a computer-based design tool that will enable existing design families to be transformed into 'dynamic' CAD-based models for the Conceptual, Embodiment and Detailed stages of the design process. Two novel concepts are proposed here, i) the use of a Function Means Tree to store Conceptual and Embodiment design and ii) a Variant Method to represent Detailed design. In this way a definite link between the more abstract conceptual and the concrete detailed design stages is realised by linking individual detailed designs to means in the Function Means Tree. The use of the Variant Method, incorporating 'state-of-the-art' developments in Solid Modelling, Feature-Based Design and Parametric Design, allows an entire family of designs to be represented by a single Master Model. Therefore, instances of this Master Model need only be stored as a set of design parameters. This enables current design families and new design cases to be more created more efficiently. Industrial Case Studies, including a Lathe Chuck family, a Drive-End casting and a family of Filtration Systems are given to prove the methodology.
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Mora, Carlos A. "Comparison of computation methods for CBM production performance." [College Station, Tex. : Texas A&M University, 2007. http://hdl.handle.net/1969.1/ETD-TAMU-1958.
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Berndt, Karsten, and Marko Ebermann. "Methodik zur funktionsorientierten Tolerierung mittels CAD-basierter Analysen." Universitätsbibliothek Chemnitz, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-171981.
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Teil 1 Karsten Berndt
Die Festlegung von Toleranzen ist eine alltägliche Aufgabenstellung des Konstrukteurs. Dabei bedingt die Berechnung nichtlinearer Toleranzketten einen erheblichen Zeitaufwand, wodurch meist auf deren genaue Berechnung vezichtet wird und Toleranzen stattdessen auf Basis von Erfahrungswerten festgelegt werden. Die vorgestellte Methodik zeigt Wege, wie schnell und frühzeitig im Konstruktionsprozess belastbare Aussagen zu Toleranzen komplexer Mechanismen getroffen werden können. Dazu werden sogenannte Sensitivitätsanalysen in der CAD-Software "Creo Elements" durchgeführt und ausgewertet. Das Ergebnis sind erste konkrete Toleranzfelder für alle den Mechanismus beschreibenden, geometrischen Abmessungen, welche sich als Startwerte für den anschließenden Toleranzsynthese/-analyseprozess eignen.
Teil 2 Marko Ebermann
Dieser zweite Vortragsteil behandelt eine mögliche Vorgehensweise zur Tolerierung von Geometrieabweichungen in der frühen Entwurfsphase am Beispiel des Koppelgliedes einer Verpackungsmaschine. Ausgangspunkt für die frühe Tolerierung bildet die im ersten Vortragsteil behandelte Sensitivitätsanalyse des Koppelgetriebes, welche Informationen zur Empfindlichkeit der Funktionsmaße bezüglich der Einhaltung der Schließmaßtoleranz lieferte. Die daraus abgeleitete Form- und Lagetolerierung des Koppelgliedes soll durch anschließende Toleranzamalysen die Tolerierung im Baugruppenkontext bestätigen und auf möglich Fertigungsverfahren abzielen, ohne die genaue Gestalt der Komponenten zu kennen. So können teure und zeitintensive Iterationsschleifen im Konstruktionsprozess minimiert und die Funktionalität frühzeitig gesichert werden.
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Gunneriusson, Olof. "Method for determining phasedistribution and characteristic lenghts in cBN-composite materials." Thesis, Uppsala universitet, Institutionen för kemi - Ångström, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-206276.
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An image analysis method has been developed for Sandvik to determine phasecompositions and characteristic length of the binding phase in cubic Boron Nitride(cBN)-composites with low contents of cBN (35-75%).The method consists of taking pictures with a Scanning Electron Microscope,gathering elemental data with X-ray Diffraction (XRD) as well as Energy-dispersiveX-ray Spectroscopy (EDS) and finally using a Matlab program developed for this workto calculate phase compositions and statistical data from the characteristic length ofthe binding phase.Using these methods four different phases were identified in the samples: Blackparticles, most likely made of cBN. A dark gray phase around the black particles, thatconsists of Al-compounds. A light grey binding phase, consisting of TiN or Ti(C,N).Finally there were small traces of white particles which were identified as a product ofabrasive action on cermet milling bodies added during the milling.Mean value, standard deviation and median of the characteristic length of the bindingphase was calculated. For all samples the median value was consistent, sometimeseven being identical for the analyzed sites. This indicates that the binding phase wasevenly distributed across almost all samples.
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Lee, Taeyoung. "Improved slab method for axisymmetric forging." Ohio : Ohio University, 1996. http://www.ohiolink.edu/etd/view.cgi?ohiou1178221157.
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Gargoloff, Joaquin Ivan. "A numerical method for fully nonlinear aeroelastic analysis." [College Station, Tex. : Texas A&M University, 2007. http://hdl.handle.net/1969.1/ETD-TAMU-1219.
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Harper, Brian Davidson. "CAD methods to support automated De- and remanufacture assessments." Thesis, Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/16741.
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Fic, Miloslav. "Metoda hraničních vířivých elementů pro 2D proudění kapalin." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2013. http://www.nusl.cz/ntk/nusl-230563.
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This master’s thesis deals with boundary vorticity element method for 2D fluid flow. The aim of this work is to program this method with continuous vorticity lay-out and to validate method with various boundary conditions. The computed results are presented in this work. Advantages and disadvantages of each one boundary condition are pointed out. New one boundary condition for boundary vorticity element method is applied in this thesis.
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Krejcar, Pavel. "Optimalizace předmontáže planetových koleček." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2010. http://www.nusl.cz/ntk/nusl-229314.
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The aim of my thesis is a comperation with Linde Pohony s.r.o. Our aim is to suggest the realization of automatic control of pre-assembly of planetary wheels. The solution with CCD cameras and sensors is interpreted in a detailed way - treir reliability suggestibility by milieu and attendance service.The second part continue of a suggestion of automized workplace with a full detailed drawings. Abstrakt
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Menier, Victorien. "Numerical methods and mesh adaptation for reliable rans simulations." Thesis, Paris 6, 2015. http://www.theses.fr/2015PA066481/document.
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Cette thèse porte sur la prédiction haute-fidélité de phénomènes visqueux turbulents modélisés par les équations Reynolds-Averaged Navier-Stokes (RANS). Si l’adaptation de maillage a été appliquée avec succès aux simulations non-visqueuses comme la prédiction du bang sonique ou la propagation d’explosion, prouver que ces méthodes s’étendent et s’appliquent également aux simulations RANS avec le même succès reste un problème ouvert. Dans ce contexte, cette thèse traite des problématiques relatives aux méthodes numériques (solveur de mécanique des fluides) et aux stratégies d’adaptation de maillage. Pour les méthodes numériques, nous avons implémenté un modèle de turbulence dans notre solveur et nous avons conduit une étude de vérification et validation en deux et trois dimensions avec comparaisons à l’expérience. Des bons résultats ont été obtenus sur un ensemble de cas tests, notamment sur le calcul de la traînée pour des géométries complexes. Nous avons également amélioré la robustesse et la rapidité de convergence du solveur, grâce à une intégration en temps implicite, et grâce à une procédure d’accélération multigrille. En ce qui concerne les stratégies d’adaptation de maillage, nous avons couplé les méthodes multigrilles à la boucle d’adaptation dans le but de bénéficier des propriétés de convergence du multigrille, et ainsi, améliorer la robustesse du processus et le temps CPU des simulations. Nous avons également développé un algorithme de génération de maillage en parallèle. Celui-ci permet de générer des maillages anisotropes adaptés d’un milliard d’éléments en moins de 20 minutes sur 120 coeurs de calcul. Enfin, nous avons proposé une procédure pour générer automatiquement des maillages anisotropes adaptés quasi-structurés pour les couches limites<br>This thesis deals with the high-fidelity prediction of viscous turbulent flows modelized by the Reynolds-Averaged Navier-Stokes (RANS) equations. If mesh adaptation has been successfully applied to inviscid simulations like the sonic boom prediction or the blast propagation, demonstrating that these methods are also well-suited for 3D RANS simulations remains a challenge. This thesis addresses research issues that arise in this context, which are related to both numerical methods (flow solver) and mesh adaptation strategies. For the numerical methods, we have implemented a turbulence model in our in-house flow solver and carried out its verification & validation study. Accurate results were obtained for a representative set of test cases, including the drag prediction workshop. Additional developments have been done to improve the robustness and the convergence speed of the flow solver. They include the implementation of an implicit time integration and of a multigrid acceleration procedure. As regards mesh adaptation, we have coupled the adaptive process to multigrid in order to benefit from its convergence properties and thus improve the robustness while preventing losses of computational effort. We also have devised a parallel mesh generation algorithm. We are able to generate anisotropic adapted meshes containing around one billion elements in less than 20min on 120 cores. Finally, we introduced a procedure to automatically generate anisotropic adapted quasi-structured meshes in boundary layer regions
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Nakiboglu, Gunes. "Development Of An Educational Cfd Software For Two Dimensional Incompressible Flows." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/12608562/index.pdf.
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The main purpose of this research is to develop a Computational Fluid Dynamics (CFD) software
to be used as an educational tool in teaching introductory level fluid mechanics and CFD
courses. The software developed for this purpose is called Virtual Flow Lab. It has a graphical
user interface (GUI) that enables basic pre-processing, solver parameter and boundary
condition setting and post-processing steps of a typical CFD simulation. The pressure-based
solver is capable of solving incompressible, laminar, steady or time-dependent problems on
two-dimensional Cartesian grids using the SIMPLE algorithm and its variants. Blocked-cell
technique is implemented to extend the types of the problems that can be studied on a Cartesian
grid. A parametric study is conducted using a number of benchmark problems in order to
test the accuracy and efficiency of the solver and successful results are achieved.
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Bodily, Garrett Clark. "A Computational Hybrid Method for Self-Intersection Free Offsetting of CAD Geometry." BYU ScholarsArchive, 2014. https://scholarsarchive.byu.edu/etd/5293.
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Surface offsetting is a valuable tool used in Computer Aided Design (CAD). An offset surface is a collection of points that are at a constant distance from another surface. An offset surface is created in CAD by selecting a surface and then specifying the distance that the surface is to be offset. If a surface is selected and a distance of D is specified, then the resulting offset surface should always be distance D from the original surface. The surface offset tool can be used for many applications. Modeling of composites or other layered manufacturing processes rely heavily on offset surfaces. Thin walled parts such as injection molded components are often modeled using the offset tool. Coating processes can also be modeled using the offset tool. Modern CAD systems have surface offsetting tools and are widely used throughout industry. However, CAD systems often fail to produce valid results. The process of surface offsetting can often result in surface self-intersections as well as surface degeneracies. Self-intersections and degeneracies make the surfaces invalid because they are physically impossible to create and CAD systems cannot use these invalid surfaces to represent solid bodies. The surface offset tool is therefore, one of the most challenging CAD tools to implement. The process of avoiding, detecting and removing surface self-intersections is extremely challenging. Much research in the field of CAD is dedicated to the detection and removal of surface self-intersections. However, the methods proposed in the literature all suffer from robustness problems. The purpose of this research is to introduce a method that creates valid offset surfaces and does not suffer from the problem of creating surface self-intersections. This method uses a numerical approach that approximates the offset surface and avoids all self-intersections. Because no self-intersections are created, the method does not require intersection tests of any kind. The value of this method is demonstrated by comparing its results with results from leading CAD systems.
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Huayamave, Victor. "DESIGNING OF ENERGY EFFICIENT INDOOR ENVIRONMENTS USING A LOCALIZED RADIAL BASIS FUNCTION MESHLESS METHOD." Master's thesis, University of Central Florida, 2010. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/2843.
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Around the world, the energy over consumption issue has been one of the key socio-economic and political challenges, which has drastically worsened over the last few years. Over the years engineers and environmentalists have proposed several approaches to improve energy efficiency. One is to reduce energy demand by improving consumption habits and a second approach is to introduce the use of a "greener" concept by using biomaterials in a diverse and more efficient manner in engineering construction to create energy efficient environments. This work will investigate the effects of using "green" stabilized earth materials to provide and enhance thermal regulation for indoor environments. This effects can be compared to what skin does to regulate body temperature in humans, animals, and plants. On this effort the thermal behavior of several biomaterials will be analyzed using a computational tool in order to test the mechanical properties of biomaterials and also several geometry configurations to minimize the energy needed for heating and cooling an environment. In this research a localized radial basis function (LRBF) meshless method, developed by the Computational Mechanics Lab (CML) at the University of Central Florida, has been implemented to test several wall geometrical configuration using known biomaterials such as clay. The advantage of using the LRBF meshless method in this particular research is based in the accuracy of the numerical method and also because it decreases computation time regardless of model complexity geometry without the need of mesh generation. This research includes a complete description of the LRBF meshless method, as well as a quantification of cooling methods that have been used by past civilizations and recent construction standards but have not been validated on scientific basis. Results are presented which will demonstrate the effectiveness of using integrated sheets of biomaterials in engineering construction to increase energy efficiency in indoor environments.<br>M.S.<br>Department of Mechanical, Materials and Aerospace Engineering<br>Engineering and Computer Science<br>Mechanical Engineering MSME
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Larsson, Filip. "3D-skanning av objekt skapad i CAD - metod och toleransanalys." Thesis, Umeå universitet, Institutionen för tillämpad fysik och elektronik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-174808.
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I detta examensarbete beskrivs, testas och utvärderas tekniken strukturerat ljus 3D-skanning under användning av en kommersiell 3D-skanner. Arbetet utfördes på institutionen för tillämpad fysik och elektronik vid Umeå universitet och tanken med arbetet var att det ska underlätta implementering av 3D-skanning i undervisningen för högskoleingenjörsprogrammet maskinteknik. Tre olika objekt skapades i CAD och skrevs ut i en 3D-skrivare för att sedan skannas in med 3Dskannern. En noggrann toleransanalys med en tolerans på 0,2 mm utfördes genom att mäta och jämföra olika mått mellan CAD-modell, 3D-utskriven modell och 3D-skannad modell. Hela processen från CAD till insamling av mätdata och inskannad 3D-modell är väldokumenterad i form av en guide. Det beskrivs vilka tekniska funktioner skannern har och om den uppfyller kraven som ställs på dess noggrannhet och precision. Resultaten för arbetet visar att skannern är kapabel att återskapa fysiska objekt med stor noggrannhet och kan användas för att göra en toleransanalys. Beroende på typ av objekt, kommer en av de tre olika skanningsmetoderna, Fixed Scan, Rapid Scan eller HD Scan ge bäst prestanda. Utifrån resultaten för de objekt som skapades kan man se att skannern är mest lämpad för att skanna detaljrika objekt, avancerade geometrier och ytor med låg reflektion.<br>In this thesis, the technology structured light 3D-scanning is described, tested and evaluated using a commercial 3D-scanner. The work was carried out at the Department of Applied Physics and Electronics at Umeå University and the idea of the work was to facilitate the implementation of 3D-scanning in the mechanical engineering program. Three different objects were created in CAD and printed out from an 3D-printer and then scanned in with the 3D-scanner. A detailed tolerance analysis with a tolerance of 0.2 mm was performed by measuring and comparing different distances on the CAD model, the 3D-printed model and the 3D-scanned model. The entire process from CAD to collection of measurement data and 3Dscanned model is well documented in the form of a guide. It describes the technical functions of the scanner and whether it meets the requirements for its expected accuracy and precision. The results of the work show that the scanner is capable of recreating physical objects with great accuracy and can be used to perform a tolerance analysis. Depending on the type of object being scanned, one of the available three different scanning methods, Fixed Scan, Rapid Scan or HD Scan, will provide performance. Based on the results of the objects created, it can be seen that the scanner is best suited for scanning detailed objects, advanced geometries and surfaces with low reflectivity.
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Bay, Raymond James. "Improved Design Method for Cambered Stepped Hulls with High Deadrise." Thesis, Virginia Tech, 2019. http://hdl.handle.net/10919/90298.
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Eugene Clement created a design method for swept-back cambered step hulls with deadrise.
The cambered step is designed to carry 90% of the planing vessels weight with the remaining
10% being support by a stern mounted hydrofoil. The method requires multiple design
iterations in order to achieve an optimal design. Clement stated that the method was not
suitable for cambered planing surfaces with high deadrise angles greater than 15 degrees.
The goal of this thesis is to create a design procedure for swept-back cambered planing
surfaces with high deadrise angles that does not require multiple iterations to obtain an
optimal design. Computational fluid dynamics (CFD) program STAR CCM+ is used to
generate a database for performance characteristics for a wide range of designs varying
deadrise angle, load requirements, trim angle, and different camber values. The simulations
are first validated with experimental data for two different cambered steps designed by
Stefano Brizzolara and tested in the tow tank at the United States Naval Academy. A series
of validation studies utilizing fixed and overset meshes led to a final simulation set up with an
overset mesh that allowed for accurate prediction of drag, trim moment, wetted keel length,
and the wake profile aft of the cambered planing surface. The database is fitted such that
the final equations for optimal design values such as camber, trim angle, drag (shear and
pressure), wetted keel length, wetted surface area, and trim moment are in terms of deadrise
angle and lift. The optimized design equations are validated with CFD simulation.<br>Master of Science<br>Eugene Clement developed a new design method to improve the performance of ultra-fast planing crafts. A planing craft uses the force generated from the flow of water over the bottom to lift the vessel without the use of the static buoyancy force that classic boat designs rely on. Clement wanted to improve the performance of the planing vessel by reducing the total drag force caused by the flow of water on the bottom of the vessel. ClementâĂŹs design method involves reducing the wetted surface area which reduces drag. Reducing the wetted surface area would normally cause the lifting force on the vessel to reduce, but with the addition of curvature in the smaller wetted surface area, the lifting force would remain the same. ClementâĂŹs new design method requires multiple iterations to obtain an optimal design. The method limits the angle of the vessels bottom relative to horizontal to under 15 degree. The goal of this thesis is to create a new design method for planing vessels with bottoms that have an incline of 15 degrees or more relative to horizontal. The design method is created using Computational Fluid Dynamics (CFD) solver to model the planing surface moving through water. The CFD solver is validated with experimental test performed at the United States Naval Academy. The improved design method uses equations that can predict the forces and other design characteristics based on the desired vessel weight and seakeeping requirements.
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Hunter, William. "Actuator disk methods for tidal turbine arrays." Thesis, University of Oxford, 2015. https://ora.ox.ac.uk/objects/uuid:bf8e95df-9e67-4c89-8d9d-1a608a8be0f4.
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Tidal stream energy presents challenges that will require the development of new engineering tools if designs are to harness this energy source effectively. At first glance one might imagine that tidal stream energy can be treated as wind with appropriate adjustment for fluid properties of water over air, and account taken of the harsher offshore environment; both waves and turbulence. However, it is now well accepted that the flow past turbines that are constrained by the local sea bed, sea surface, and possibly also neighbouring turbines and channel sides, will differ markedly from that of an ostensibly unblocked wind turbine. Garrett & Cummins (2007) were the first to demonstrate that operating a turbine in a non- negligibly blocked flow passage presents a different flow solution and importantly a significant opportunity to enhance the power that can be delivered by blocked turbines with the limit of power extraction exceeding the Lanchester-Betz limit for operation of unblocked wind turbines. Although it is impractical to array real turbines across the entire width of a channel it has been proposed to use short arrays of turbines making use of local constructive interference (blockage) effects; Nishino & Willden (2012) showed that although the phenomenal power limits of Garrett & Cummins are unobtainable in a real flow, a significant uplift in the limit of power extraction can be achieved for short fences of turbines arrayed normally to the flow in wide cross-section channels. However, it does not follow that rotors designed using unblocked wind turbine tools are capable of extracting any more power than they are designed for and hence the power uplift made available through blockage effects may be squandered. This thesis sets out to develop design tools to assist in the design of rotors in blocked environments that are designed to make use of the flow confinement effects and yield rotors capable of extracting some of the additional power on offer in blocked flow conditions. It is the pressure recovery condition used in wind turbine design that requires relaxation in blocked flow conditions and hence it is necessary to resort to a computational framework in which the free stream pressure drop can be properly accounted for. The tool of choice is a computational fluid dynamics embedded blade element method. As with all models with semi-empirical content it is necessary to select and test correction models that account for various simplifications inherent to the use of the blade element method over a fully blade resolved simulation. The thesis presents a rigorous comparison of the computational model with experimental data with the various correction methods employed. The tool is then used to design rotors, first for unblocked operation, with favourable comparison drawn to lifting line derived optimal Betz rotor solutions. The final objective of the study is to design rotors for operation in short fence configurations of four turbines arrayed normally to the flow. This is accomplished and it is shown that by using bespoke in situ rotor design it is possible to extract more power than possible with non-blockage designs. For the defined array layout and operating conditions, the bespoke rotor array design yields a power coefficient 26% greater than the implied Betz limit for an unblocked rotor and 4% greater than operating a rotor designed in isolation in the same array.
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Krauze, Maciej. "J/[phi] level one trigger based on the Cellular Automaton method for CBM experiment." Doctoral thesis, Katowice : Uniwersytet Śląski, 2011. http://hdl.handle.net/20.500.12128/5299.
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Głównym tematem pracy jest selekcja zdarzeń zawierających mezon J /ip przy użyciu Detektora Promieniowania Przejścia. Stworzone procedury działają na niskim poziomie (Poziom 1) systemu akwizycji danych eksperymentu Compressed Baryonic Matter. Na potrzeby poszukiwania sygnatury mezonu stworzono dedykowany algorytm rekonstrukcyjny. Jako sygnaturę wybrano parę e+e_ z pędem poprzecznym każdej cząstki pt > 1 GeV/c i o masie niezmienniczej w okolicach 3.1 GeV/c2. Algorytm rekonstrukcyjny
bazuje na idei Automatu Komórkowego, optymalnej dla równoległego przetwarzania danych. Podczas selekcji, zdarzenia pozbawione interesujących informacji są odrzucane a te zawierające sygnaturę rozpadu J/ip są akceptowane. Algorytm rekonstruuje tory wysokopędowych (p > 1 GeV/c) cząstek z pojedynczego centralnego zderzenia Au+Au przy energii 25 GeV/nukleon z wydajnością 92.6% w czasie 0.24 s na standardowym.
3-gigahercowym procesorze klasy Pentium 4. Dla zderzeń peryferyjnych przy tej samej energii, wydajność dla wysokopędowych cząstek wynosi 89.7% a czas jednego zdarzenia to 0.05 s. Wyniki pokazują, że oparta na sygnaturach selekcja zdarzeń pozwala na redukcję ilości zdarzeń tła dla kolizji peryferyjnych o czynnik 1000. przepuszczając 1 zdarzenie tła na 1000 przy zachowaniu 11.7 % zdarzeń z sygnałem z rozpadu J/ip .
Oferuje 1000 razy więcej czasu dla systemów analizy wyższego rzędu na przeprowadzenie
dodatkowych operacji w trybie on-line.
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Kandelid, Stefan. "Work method for 3D modeling in pro/ENGINEER." Thesis, Örebro universitet, Institutionen för naturvetenskap och teknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-23486.
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This is a 15 credits thesis in mechanical engineering performed at the PLM Solutions group at the Rocktec division within Atlas Copco Rock Drills AB, Örebro, during spring 2012. When designers working with 3D CAD modeling uses different work methods in Pro/ENGINEER (Pro/E) it sometimes results in problems. It is also a problem when designers do not follow the specific work methods defined by Atlas Copco. The purpose of this thesis was to identify the most common problems with 3D models at Atlas Copco Rock Drills AB (RDE) Örebro related to work methods, for example why models crash, why they cannot be checked in to Pro/Intralink or why there are unstable references. The objective was to present a work method to avoid one or two of the most severe problems identified at RDE Örebro. To achieve the objective I started with going through the CAD support call data base, to find out in what areas the organization needed help from the CAD support. The result shows that the engineers request most support in how to use both the modeling and the drawing modules in Pro/E. I also came up with a suggestion for redesign of the CAD support call data base system, that could reduce the time needed for this kind of analysis from days to minutes. Thereafter a number of engineers, all with high skills in Pro/E, were selected for personal interviews. The topic was to identify any lack in defined work methods in Pro/E causing problems that are taking long time to correct. The result shows that the biggest issue for the users is references. I also performed a benchmarking with two other companies within the Atlas Copco Group looking at their CAD guidelines regarding the issues found during the interviews. Thirdly, one assembly each from six different departments were selected and sent to PTC for an in depth analysis with their software tool Expert Model Analysis. The goal was to find any systematic issues regarding work methods in Pro/E. The analysis confirmed what the engineers earlier had brought up as the main issues, namely, references, mass/weight handling and structure in the model tree.<br>Detta är en 15 hp examensarbete i maskinteknik som utförs på PLM Solutions Group på Rocktec divisionen inom Atlas Copco Rock Drills AB i Örebro, under våren 2012.När konstruktörerna arbetar med 3D CAD modellering använder de olika arbetsmetoder i Pro/ENGINEER (Pro/E) vilket ibland leder till problem. Det är också ett problem när konstruktörerna inte följer de arbetsmetoder som definierats av Atlas Copco.Syftet med detta examensarbete var att identifiera de vanligaste problemen med 3D-modeller på Atlas Copco Rock Drills AB (RDE) i Örebro relaterat till arbetsmetoder, till exempel varför modellerna kraschar, varför de inte kan checkas in i Pro/Intralink eller varför det finns instabila referenser. Målet var att presentera en arbetsmetod för att undvika ett eller två av de mest allvarliga problemen identifierade vid RDE Örebro. För att uppnå målet började jag med att gå igenom CAD-supportens samtalsdatabas, för att ta reda på inom vilka områden användarna behövde hjälp från CAD-support. Resultatet visar att konstruktörerna behöver mest hjälp med hur man använder både modellerings- och ritningsmodulerna i Pro/E. Jag tog också fram ett förslag till hur CAD-supportens samtalsdatabas kan göras om, som skulle kunna minska tiden som behövs för denna typ av analys från dagar till minuter. Därefter valdes ett antal ingenjörer ut, alla med hög kompetens inom Pro/E, för personliga intervjuer. Syftet var att identifiera eventuella brist i befintliga arbetsmetoder i Pro/E, vilka orsakar problem som tar lång tid att rätta till. Resultatet visar att det största problemet för användarna är referenser. Jag utförde också en benchmarking med två andra bolag inom Atlas Copco-gruppen genom att jämföra deras CAD rekommendationer kring de problem som kom fram under de tidigare intervjuerna. Som tredje del i examensarbetet valdes en CAD-modell från vardera sex olika avdelningar och skickades till PTC för en fördjupad analys med deras program Expert Model Analysis (XMA). Målet var att hitta systematiska problem gällande arbetsmetoder i Pro/E. XMA-analysen bekräftade vad ingenjörerna tidigare hade fört fram som de viktigaste frågorna, nämligen referenser, massa/vikt hantering och struktur i modellen trädet.
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McCormick, A. H. I. "Application of the moment method to the design of slotted waveguide array antennas." Thesis, Heriot-Watt University, 1988. http://hdl.handle.net/10399/1962.
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Horák, Aleš. "Výroba prototypu automobilu s využitím moderních metod a technologie CAD/CAM." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2010. http://www.nusl.cz/ntk/nusl-229335.
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The project developed under the engineering studies, solves the problem of production of a prototype car using modern technology, reverse engineering and CAD / CAM. Based on the literary study of the issue, was designed process of digitization of the physical model of car, including the treatment and processing of data. Follow-up step was to verify the production of the additive rapid prototyping technology - FDM method. Verification of the results was performed on a vertical milling cantilever FV 25 CNC with control system Heidenhain iTNC 530 using a cutting strategies by PowerMILL CAM software. At the end of the resulting models edit as necessary.
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Huang, Yihan. "Extrusion die design using finite element method for sheet and pipe dies." Thesis, Nottingham Trent University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.297736.
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Katzenbach, Alfred, and Peyman Merat. "Methodik zum Austausch eines CAD Systems in einem Großunternehmen." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-228005.
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Nach einem 10 bis 15 Jahre dauernden Lebenszyklus besteht die Notwendigkeit große IT-Systeme durch eine neue Generation zu ersetzen. Dabei ist es vom Aufwand her unwesentlich, ob es sich um einen Generationswechsel des gleichen Herstellers handelt oder um die vergleichbare Lösung eines anderen Herstellers. Im beschriebenen Fall hat sich die Daimler AG im November 2010 entschieden auf ein anderes CAD-System zu wechseln und die Migration bis Ende 2016 abzuschließen. Der Beitrag zeigt die Vorgehensweise der Umstellung unter fünf Aspekten:
— Anwendungsmethodik inkl. Datenarchivierung
— Datenmigration
— Use-Case-Absicherung
— Rolloutplanung
— Schulungskonzept
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Ng, Ping-leung, and 吳炳樑. "Assessment of performance of different computational methods (DFT and MP2) with different levels of basis sets benchmarked by CBS-QB3 methodby selected reactions." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B45607266.
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Jeong, Namin. "A surfacelet-based method for constructing geometric models of microstructure." Diss., Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/54438.
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Integration of material composition, microstructure, and mechanical properties with geometry information enables many product development activities, including design, analysis, and manufacturing. To address such needs, models of material composition have been integrated into CAD systems, creating systems called heterogeneous CAD modeling. In order to support the heterogeneous CAD system, extensive process-structure-property relationships have to be captured and integrated into current CAD system. A new method for reverse engineering of materials will be presented such that microstructure models can be constructed and used in the heterogeneous CAD system.
Reverse engineering of material consists of three parts: image analysis, structure-property-process relationship, and repository. In this research, an image processing method, which comprises the Radon transform and the wavelet transform, will be used in order to recognize geometric features from a microstructure image. Recognizing geometric features can be obtained by combinations of three techniques, masking, clustering, and high frequency component on wavelet transform, that are integrated with the Radon transform. Then, recognized geometric features can be used to construct an explicit geometric model of microstructure. The proposed work will provide an explicit mathematical method to recognize and to quantify microstructure features from an image. In addition, explicit geometric models of microstructure can be automatically constructed and utilized to get effective mechanical properties, establishing structure-property relationship of the material. In order to demonstrate this, polymer nano-composite sample and metal alloy sample will be used.
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Koosukuntla, Narender Reddy. "Towards Development of a Multiphase Simulation Model Using Lattice Boltzmann Method (LBM)." University of Toledo / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1321629685.
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Chaudhari, Sachin B. "DEVELOPMENT OF AN INTERNET-BASED ANALYSIS TOOL USING THE BOUNDARY ELEMENT METHOD." University of Cincinnati / OhioLINK, 2000. http://rave.ohiolink.edu/etdc/view?acc_num=ucin971963697.
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Guillermo-Monedero, Daniel. "A Comparison of Euler Finite Volume and Supersonic Vortex Lattice Methods used during the Conceptual Design Phase of Supersonic Delta Wings." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1576713976622162.
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Doupník, Petr. "Využití optimalizačních metod při návrhu transsonického křídla s implementací základních konstrukčně pevnostních omezení." Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2010. http://www.nusl.cz/ntk/nusl-233939.
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The thesis gives overview of complex aerodynamic optimization approach applied to business-jet aircraft wing design. Response surface method (RSM) potential was explored particularly. The efficiency of RSM approach for CFD based aerodynamic optimization was demonstrated. Basic structural requirements were successfully integrated to optimization – real multidisciplinary problem was solved. Some methods for evaluation of forces distribution along wingspan were explored. Thesis was solving within the frame of 6th EU FP integrated project CESAR.
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Bölke, Kristofer. "IRONARC; a New Method for Energy Efficient Production of Iron Using Plasma Generators." Thesis, KTH, Materialvetenskap, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-173357.
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The most widely used process to reduce iron ore and to produce pig iron is the blast furnace. The blast furnace is a large source of CO2 emissions since it is a coal based process and due to that the main energy source and reducing agent is coke, it is difficult to reduce these further. IRONARC is a new method used to produce pig iron by reducing iron ore and all the energy used for heating comes from electricity, which gives the opportunity to use renewable resources. The process uses plasma generators that inject gas at high temperature and velocity into a slag that consists of iron oxides. The iron oxides are reduced in two steps that appear by using gas as reduction agent in the first step and carbon in the second step. It exists in a smaller pilot plant scale and this project was the first step in the future upscaling of the IRONARC process. Computational Fluid Dynamics (CFD) modelling was used and the goal was to determine the penetration depth of the IRONARC pilot plant process by numerical simulation in the software ANSYS FLUENT. The penetration depth is of importance because to be able to scale up the process it is important to know the flow pattern and the structure of the flow in the process, which is dependent on how far into the slag the gas reaches. Two numerical models were made. First an air-water model that described the initial penetration of air injected into water. The air-water simulation was made with parameters and data from an experiment found in literature. This was done to build an accurate CFD model for the penetration depth in FLUENT and validate the model with the results of the penetration depth from the experiment. The air-water simulation gave good and promising results and yielded the same result regarding the penetration depth as the experiment. The model for the penetration depth was then used with the IRONARC geometry and parameters. After simulation the penetration depth of the IRONARC process was determined. For the future, the penetration depth of the pilot plant needs to be measured and compared with the simulated result for the penetration depth.
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Grieve, M. D. "Self-adaptive methods for computer-aided design of electromagnetic systems." Thesis, University of Aberdeen, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.382136.
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Hegedüs, Krisztián. "CAD - Methoden des Konstruktionsprozesses im Glasbau Wissensakquisition, Forschung und Entwicklung /." [S.l.] : [s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=973067799.
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Hegedűs, Krisztián. "CAD - Methoden des Konstruktionsprozesses im Glasbau Wissensakquisition, Forschung und Entwicklung /." [S.l. : s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=973067799.
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Pleva, František. "Metoda odezvových ploch ve spojení s CFD pro tvarovou optimalizaci." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2021. http://www.nusl.cz/ntk/nusl-449797.
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This thesis is focused on shape optimization of Venturi´s nozzle with optimization method called response surface method. The first part of this work is concerned with the description of this method as well as explaining the basic principle. Furthermore, there is an explanation of the application of this method in synchronicity with CFD and its operating algorithm. The second part of this thesis is then focused on simple example with plane wing and simplified optimization of Venturi´s nozzle in which this method was tested. In the third part there is described full multiparameter shape optimalization of the nozzle for two geometries.
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Crona, Cecilia. "Sjuksköterskors erfarenheter av KBT i samtalet i psykiatrisk heldygnsvård : Utifrån manualbaserad KBT." Thesis, Röda Korsets Högskola, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:rkh:diva-4015.
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Background: It has been under discussion in Sweden that the psychiatric inpatients ward is in the need of developing more content and structure. Earlier science shows that implementation of new conversations methods has been appreciated and developing for both nurses and patients. There is also obstacle for nurse`s to prioritize time for conversations with their patients. Aim: The aim was to explore nurse`s experiences of using a manual based CBT in conversations with patients in psychiatric inpatient ward. Method: Research design was interviews with qualitative approach and thematic analysis, inductive approach. Six nurses who worked in a psychiatric inpatients ward were interviewed. Results: The results of the study were summarized in to two main themes; Feelings in work as a nurse and the nurse in the professional role. Six under themes was conducted into the two mentioned main themes. Its presenting feelings connected to these conversations with CBT methodand about the professional working role. It was described useful in the daily work and agood support for the patient recovery, person-centered treatment and difficulties associated to the implementation of the new work. Conclusion: Cbt makes it possible to make in dept-care relationship, strengthens patients' recovery and provides structure for the conversation which also requires support and adaptation for making it useful in the daily work.<br>Bakgrund: Det har diskuterats i Sverige om att den psykiatrisk heldygnsvården är i behov av utveckling vad gäller innehåll och struktur. Tidigare forskning har visat att införandet av samtalsmetoder har varit uppskattat och utvecklande för både sjuksköterskor och patienter. Det finns också hinder för sjuksköterskor att prioritera tid för samtal med patienter. Syfte: Syftet med denna magisteruppsats var att utforska sjuksköterskors erfarenheter av att använda sig av manualbaserad KBT i samtalet med patienter i psykiatrisk heldygnsvård. Metod: Designen var intervjustudie med kvalitativ ansats och tematisk analys med induktiv approach. Sex sjuksköterskor intervjuades och de var yrkesverksamma på psykiatriska heldygnsvårdsavdelningar. Resultat: Resultatet presenteras i två huvudteman; Känslor i arbetet som sjuksköterska och sjuksköterskan i sin professionella roll. Sex undertemandelades in under de två huvudkategorierna. Det presenteras känslor kopplade till sjuksköterskans arbete med KBT metoden i samtalet likväl som det handlade om den professionella yrkesrollen. Det beskrevs som hjälpsamt för patienters återhämtning, personcentrerat bemötande samt vissa svårigheter kopplat till det nya arbetssättet. Slutsats: KBT möjliggör fördjupad vårdrelation, stärker patienters återhämtning och ger struktur för samtalet. Vilket ocksåbör backas upp med stöd omkring införandet och med viss anpassning för att det skall bli användbart i det dagliga arbetet.
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Sedláček, Petr. "Pevnostní a modální analýza v parametrických adaptivních CAD programech." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2010. http://www.nusl.cz/ntk/nusl-218805.
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This thesis is focusing on the use of the finite element method (FEM) in program environment of Autodesk Inventor Professional (AIP) 2010. For the analysis of the components or assemblies with FEM serves the Strength analysis module of the AIP 2010, whose environment and functions are detailed in this thesis. At the conclusion practical examples of modal and static analysis on the synchronous generator rotor model are demonstrated including a brief evaluation of the results.
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Kaufmann, Willem. "Extended Hydrodynamics Using the Discontinuous-Galerkin Hancock Method." Thesis, Université d'Ottawa / University of Ottawa, 2021. http://hdl.handle.net/10393/42672.
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Moment methods derived from the kinetic theory of gases can be used for the prediction of continuum and non-equilibrium flows and offer numerical advantages over other methods, such as the Navier-Stokes model. Models developed in this fashion are described by first-order hyperbolic partial differential equations (PDEs) with stiff local relaxation source terms.
The application of discontinuous-Galerkin (DG) methods for the solution of such models has many benefits. Of particular interest is the third-order accurate, coupled space-time discontinuous-Galerkin Hancock (DGH) method. This scheme is accurate, as well as highly efficient on large-scale distributed-memory computers.
The current study outlines a general implementation of the DGH method used for the parallel solution of moment methods in one, two, and three dimensions on modern distributed clusters. An algorithm for adaptive mesh refinement (AMR) was developed alongside the implementation of the scheme, and is used to achieve even higher accuracy and efficiency.
Many different first-order hyperbolic and hyperbolic-relaxation PDEs are solved to demonstrate the robustness of the scheme. First, a linear convection-relaxation equation is solved to verify the order of accuracy of the scheme in three dimensions. Next, some classical compressible Euler problems are solved in one, two, and three dimensions to demonstrate the scheme's ability to capture discontinuities and strong shocks, as well as the efficacy of the implemented AMR. A special case, Ringleb's flow, is also solved in two-dimensions to verify the order of accuracy of the scheme for non-linear PDEs on curved meshes. Following this, the shallow water equations are solved in two dimensions. Afterwards, the ten-moment (Gaussian) closure is applied to two-dimensional Stokes flow past a cylinder, showing the abilities of both the closure and scheme to accurately compute classical viscous solutions. Finally, the one-dimensional fourteen-moment closure is solved.
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Boyle, Iain Mackinnon. "CAFixD: A case-based reasoning method for fixture design." Link to electronic dissertation, 2006. http://www.wpi.edu/Pubs/ETD/Available/etd-050406-131631/.
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Linton, Daniel. "A Hybrid Computational Fluid Dynamics Method for Unsteady Simulation of the Ship-Helicopter Dynamic Interface." Thesis, University of Sydney, 2020. https://hdl.handle.net/2123/22894.
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Helicopters operating from ships are exposed to turbulent airwakes which can determine ship-helicopter operating limits. During concurrent operations rotor-rotor interactions add to the complexity of the aerodynamics. Computational fluid dynamics solvers are able to predict these aerodynamics from first principles with the aid of turbulence-resolving approaches such as detached eddy simulation. Although it is possible to create body-fitted grids to resolve the rotor blades and move them, the fuselage, and the ship relative to one another, this is a computationally expensive and labour intensive method. To avoid this expense and while accurately predicting unsteady loading, a time accurate rotor model has been coupled to a Navier-Stokes solver by introducing momentum source terms to the governing equations. A novel coupling algorithm that accounts for the effects of unsteady aerodynamics as well as the induced velocity of the wake has been developed and validated. The coupled rotor model predicts performance, thrust and torque distributions, and unsteady aerodynamic loading of isolated and interacting rotors. A time accurate wake can also be generated by the model. The method requires far fewer grid points to resolve the rotor than a body-fitted grid and grids can be generated automatically. Navier-Stokes simulation of the ship airwake is a complex task and many of the parameters of importance for such simulations have been identified in the literature. A study of grid convergence of velocity spectra and analysis of finite sample error have been performed to add to this knowledge. A method for objectively assessing the finite sample error and determining the minimum sample time required to reach a certain error has been applied to ship airwake simulations for the first time and a minimum level of grid refinement for resolved velocity spectra suggested. The ship airwake and rotor model have been combined for ship-helicopter dynamic interface simulations of single helicopter operations and concurrent helicopter operations involving five rotors. These simulations demonstrate the ability of the method to predict the aerodynamic factors that influence ship-helicopter operating limits and, to the best of our knowledge, contain more vehicles than any previously published dynamic interface simulations.
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Erdem, Ayan. "Performance Analyses Of Newton Method For Multi-block Structured Grids." Thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613704/index.pdf.
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In order to make use of Newton&rsquo<br>s method for complex flow domains, an Euler multi-block Newton solver is developed. The generated Newton solver uses Analytical Jacobian derivation technique to construct the Jacobian matrices with different flux discretization schemes up to the second order face interpolations.
Constructed sparse matrices are solved by parallel and series matrix solvers. In order to use structured grids for complex domains, multi-block grid construction is needed. Each block has its own Jacobian matrices and during the iterations the
communication between the blocks should be performed. Required communication is performed with &ldquo<br>halo&rdquo<br>nodes. Increase in the number of grids requires parallelization to minimize the solution time. Parallelization of the analyses is performed by using matrix solvers having parallelization capability. In this thesis, some applications of the multi-block Newton method to different
problems are given. Results are compared by using different flux discretization schemes. Convergence, analysis time and matrix solver performances are examined for different number of blocks.
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Bettemir, Onder Halis. "Sensitivity And Error Analysis Of A Differential Rectification Method For Ccd Frame Cameras And Pushbroom Scanners." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12607708/index.pdf.
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In this thesis, sensitivity and error analysis of a differential rectification method were performed by using digital images taken by a frame camera onboard BILSAT and pushbroom scanner on ASTER. Three methods were implemented for Sensitivity and Uncertainty analysis: Monte Carlo, covariance analysis and FAST (Fourier Amplitude Sensitivity Test). A parameter estimation procedure was carried out on the basis of so called Mixed Model extended by some suitable additional regularization parameters to stabilize the solution for improper geometrical conditions of the imaging system. The effectiveness and accuracy of the differential rectification method were compared with other rectification methods and the results were analyzed. Furthermore the differential method is adapted to the pushbroom scanners and software which provides rectified images from raw satellite images was developed.
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Hunt, Cahill. "Developing an efficient method for generating facial reconstructions using photogrammetry and open source 3D/CAD software." Thesis, Hunt, Cahill (2017) Developing an efficient method for generating facial reconstructions using photogrammetry and open source 3D/CAD software. Masters by Coursework thesis, Murdoch University, 2017. https://researchrepository.murdoch.edu.au/id/eprint/39826/.
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The identification of deceased individuals is important in society as it not only facilitates the progression of criminal investigations into suspicious deaths, but also enables the resolution of legal matters and brings closure to the families affected by the death. When a corpse is skeletonized, heavily burned, or the soft tissue has degraded to a point that other professionals cannot obtain information about the deceased, a forensic anthropologist or odontologist is often tasked with identification. A variety of methods exist that enable forensic anthropologists to achieve identification. These include: non-imaged records comparisons; craniofacial superimposition and comparative radiography. Facial reconstructions can also be utilized when no ante mortem information about the deceased individual is available or when law enforcement have no suspicions on who the deceased person is. Facial reconstructions are traditionally a manual method however with the recent advancement of photogrammetry and three-dimensional and computer-aided design modeling software, the process can be performed within a virtual space. The purpose of this literature review is to identify an efficient and low-cost method of generating facial reconstructions using photogrammetry and open-source three-dimensional and computer-aided design software.
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Arnesson, Frida. "WORK METHOD TO SIMPLIFY TRANSFER OF 3D MODELS TO ANSYS FOR ANALYSIS AT ATLAS COPCO ROCK DRILLS AB." Thesis, Örebro universitet, Akademin för naturvetenskap och teknik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-16097.
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GUIDOTTI, EMANUELE. "Analysis of the Unsteady Flow in an Aspirated Counter-Rotating Compressor Using the Nonlinear Harmonic Balance Method." University of Cincinnati / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1218690946.
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ZAMOLO, RICCARDO. "Radial Basis Function-Finite Difference Meshless Methods for CFD Problems." Doctoral thesis, Università degli Studi di Trieste, 2019. http://hdl.handle.net/11368/2991045.
Full textAbstract:
The objective of this dissertation is to investigate the numerical properties of the RBF-FD meshless approach when it is employed for the solution of CFD problems, with particular reference to fluid-flow problems defined over complex-shaped domains. This objective has been accomplished by developing a MATLAB code which is composed by several elements characterizing the meshless approach to a CFD problem. The work presented in this thesis has focused on the analysis and development of these characterizing elements which are essential in developing an innovative, robust, accurate and flexible numerical method.
The node generation is the first problem that has been tackled and a significant portion of this work is dedicated to this element since it is the foundation of every meshless approach. Different algorithms have been proposed for the generation of node distributions on 2D and 3D complex-shaped domains. Such node distributions then proved to be very suitable for the use with RBF-FD discretizations. The developed node generation algorithms are extremely efficient and are based on very simple principles: this is an important insight since the possibility to easily deal with complex geometries represents the main theoretical advantage of meshless methods over mesh-based methods.
The RBF interpolation, which is the key element of the RBF-FD method, is then thoroughly studied by exploring all the variables which influence the construction of an accurate and robust interpolant over scattered nodes. The multiquadric RBF has been chosen and extensive numerical tests are conducted for 2D and 3D cases. On the base of these analysis, a RBF-FD code has been developed for the local approximation of the partial derivatives of an unknown function which is defined only at scattered nodes in 2D/3D. The coupling of a node generation algorithm to a RBF-FD scheme leads to an actual meshless approach which can be used to discretize a given PDE over a domain with possible arbitrary shape. Such meshless approach has been employed to perform several test cases for different 2D/3D model problems which have fundamental importance in CFD applications.
The solution phase then follows the RBF-FD discretization, and its role in the simulation chain is just as important as the previous aspects. For this purpose, novel multicloud techniques have been proposed for the acceleration of the convergence in the solution of the system of equations arising from RBF-FD discretizations in the case of a 2D Poisson equation. Such multicloud techniques have proven to bring substantial improvements over the traditional solvers employed with the RBF-FD discretizations.
Finally, the RBF-FD approach is employed to solve actual 2D/3D fluid-flow problems in the case of the time-dependent, incompressible Navier-Stokes equations. Important problems are addressed, e.g., the development of stable discretizations when dealing with the pressure-velocity coupling using primitive variables, leading to an efficient and stable RBF-FD approach which can be used for the accurate solution of time-dependent fluid-flow problems over arbitrarily shaped domains in 2D and in 3D.<br>The objective of this dissertation is to investigate the numerical properties of the RBF-FD meshless approach when it is employed for the solution of CFD problems, with particular reference to fluid-flow problems defined over complex-shaped domains. This objective has been accomplished by developing a MATLAB code which is composed by several elements characterizing the meshless approach to a CFD problem. The work presented in this thesis has focused on the analysis and development of these characterizing elements which are essential in developing an innovative, robust, accurate and flexible numerical method.
The node generation is the first problem that has been tackled and a significant portion of this work is dedicated to this element since it is the foundation of every meshless approach. Different algorithms have been proposed for the generation of node distributions on 2D and 3D complex-shaped domains. Such node distributions then proved to be very suitable for the use with RBF-FD discretizations. The developed node generation algorithms are extremely efficient and are based on very simple principles: this is an important insight since the possibility to easily deal with complex geometries represents the main theoretical advantage of meshless methods over mesh-based methods.
The RBF interpolation, which is the key element of the RBF-FD method, is then thoroughly studied by exploring all the variables which influence the construction of an accurate and robust interpolant over scattered nodes. The multiquadric RBF has been chosen and extensive numerical tests are conducted for 2D and 3D cases. On the base of these analysis, a RBF-FD code has been developed for the local approximation of the partial derivatives of an unknown function which is defined only at scattered nodes in 2D/3D. The coupling of a node generation algorithm to a RBF-FD scheme leads to an actual meshless approach which can be used to discretize a given PDE over a domain with possible arbitrary shape. Such meshless approach has been employed to perform several test cases for different 2D/3D model problems which have fundamental importance in CFD applications.
The solution phase then follows the RBF-FD discretization, and its role in the simulation chain is just as important as the previous aspects. For this purpose, novel multicloud techniques have been proposed for the acceleration of the convergence in the solution of the system of equations arising from RBF-FD discretizations in the case of a 2D Poisson equation. Such multicloud techniques have proven to bring substantial improvements over the traditional solvers employed with the RBF-FD discretizations.
Finally, the RBF-FD approach is employed to solve actual 2D/3D fluid-flow problems in the case of the time-dependent, incompressible Navier-Stokes equations. Important problems are addressed, e.g., the development of stable discretizations when dealing with the pressure-velocity coupling using primitive variables, leading to an efficient and stable RBF-FD approach which can be used for the accurate solution of time-dependent fluid-flow problems over arbitrarily shaped domains in 2D and in 3D.
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Trafford, David B. "An investigation into methods for the evolutionary development of computer-aided design systems." Thesis, Kingston University, 1985. http://eprints.kingston.ac.uk/20502/.
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A basic requirement of all CAD systems, is that the facilities offered remain relevant to the current needs of users. A characteristic of CAD system users is that their requirements continually change or, to be more accurate, evolve, as their understanding of the design problem and available technology develops. This trait is exemplified by their inability to articulate requirements, both immediate and future with any degree of confidence. Industrial experience of using the traditional methods for developing information systems, which are based upon the Linear Life Cycle (LLC) concept, has proven to be unsuitable for CAD applications. Its failure results from the premise that users' requirements may be accurately stated at the start of the cycle and will not change with time. The need for a new development strategy which supports the evolving requirements of CAD system users is therefore evident. This research resulted in the formulation of such a development strategy. It is based upon an evolutionary approach to system development in which the users' requirements are initially satisfied by the design and implementation of a pilot sub-system which in turn forms the basis for evolution by, its incremental modification and/or extension. The success of this approach principally lies in the ability to modify the software as required with tbe minimum of resources. A major factor determining the degree to which a system may be modified was identified to beits software configuration. A number of design techniques were proposed which contributed to highly flexible configurations, principally through the criteria for functional partitioning, decoupling of functional modules from data storage and the method of organising the data. A new type of data structure was also devised which enabled new data entities and relationships to be added with no modification to the software structure. The development methods resulting from this research were extensively validated during the design and implementation of a large scale industrial CAD system.
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Hu, Guangchu. "The Development and Applications of a Numerical Method for Compressible Vorticity Confinement in Vortex-Dominant Flows." Diss., Virginia Tech, 2001. http://hdl.handle.net/10919/28516.
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An accurate and efficient numerical method for Compressible Vorticity Confinement (CVC) was developed. The methodology follows from Steinhoff's vorticity confinement approach that was developed for incompressible flows. In this research, the extension of this approach to compressible flows has been developed by adding a vorticity confinement term as a "body force" into the governing compressible flow equations. This vorticity confinement term tends to cancel the numerical dissipative errors inherently related to the numerical discretization in regions of strong vorticity gradients.
The accuracy, reliability, efficiency and robustness of this method were investigated using two methods. One approach is directly applying the CVC method to several real engineering problems involving complex vortex structures and assessing the accuracy by comparison with existing experimental data and with other computational techniques. Examples considered include supersonic conical flows over delta wings, shock-bubble and shock-vortex interactions, the turbulent flow around a square cylinder and the turbulent flow past a surface-mounted 3D cube in a channel floor. A second approach for evaluating the effectiveness of the CVC method is by solving simplified "model problems" and comparing with exact solutions. Problems that we have considered are a two-dimensional supersonic shear layer, flow over a flat plate and a two-dimensional vortex moving in a uniform stream.
The effectiveness of the compressible confinement method for flows with shock waves and vortices was evaluated on several complex flow applications. The supersonic flow over a delta wing at high angle of attack produces a leeward vortex separated from the wing and cross flow, as well as bow shock waves. The vorticity confinement solutions compare very favorably with experimental data and with other calculations performed on dense, locally refined grids. Other cases evaluated include isolated shock-bubble and shock-vortex interactions. The resulting complex, unsteady flow structures compare very favorably with experimental data and computations using higher-order methods and highly adaptive meshes.
Two cases involving massive flow separation were considered. First the two-dimensional flow over a square cylinder was considered. The CVC method was applied to this problem using the confinement term added to the inviscid formulation, but with the no-slip condition enforced. This produced an unsteady separated flow that agreed well with experimental data and existing LES and RANS calculations. The next case described is the flow over a cubic protuberance on the floor of a channel. This flow field has a very complex flow structure involving a horseshoe vortex, a primary separation vortex and secondary corner vortices. The computational flow structures and velocity profiles were in good agreement with time-averaged values of the experimental data and with LES simulations, even though the confinement approach utilized more than a factor of 50 fewer cells (about 20,000 compared to over 1 million).
In order to better understand the applicability and limitations of the vorticity confinement, particularly the compressible formulation, we have considered several simple model problems. Classical accuracy has been evaluated using a supersonic shear layer problem computed on several grids and over a range of values of confinement parameter. The flow over a flat plate was utilized to study how vorticity confinement can serve as a crude turbulent boundary layer model. Then we utilized numerical experiments with a single vortex in order to evaluate a number of consistency issues related to the numerical implementation of compressible confinement.<br>Ph. D.
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Björk, Johan. "Compressor CFD simulation method development : A CFD study." Thesis, Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-69880.
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This master thesis project consisted of three parts that all were performed through CFD simulations with the purpose to develop Scania's methods in the subject of CFD. All parts included simulations on Scania's SC92T70 centrifugal compressor. Part one consisted of performing a mesh study for the purpose of reliability, to investigate the convergence of different parameters by refining the boundary layer. The method used is an inflation option called First layer thickness. Five different meshes were generated where the Richardson extrapolation method was used to examine the parameters between the mesh renements. From the result from the examined parameters, an approximate relative error could be calculated to be less than 0.52 %, and a numerical uncertainty of less than 0.35 %, between Mesh3 and Mesh4. In addition to that, Mesh3 had a simulation time of one hour less than for Mesh4. These results motivated the use of mesh3 to be refined enough for further work in this thesis project. This mesh ended at 37, 915, 257 number of elements. The second part consisted of performing steady state CFD simulations, to examine different parameters in order to find indications of the phenomena surge. Here, experimental data was used as reliance to perform CFD simulations on the compressor. Design points from experimental data was used, that ranged from low mass flow rates where surge arises, to high mass flow rates where another phenomena called choke occur. Except for the design points taken from experimental data, a few extra design points where included at low mass flow rates (in the region of surge). The goal was that the analysis of the different parameters would generate fluctuations on the result for the design points in surge region. Four different rotational speeds on the compressor were examined, 56k, 69k, 87k and 110k revolutions per minute. A total of 140 different parameters were examined, where 10 of these indicated on surge. All of these parameters that indicated on surge where found in regions of vicinity to the compressor wheel, which are the regions subjected to the phenomena.The parameters indicating on surge where mass flow, pressure coefficient, static pressure and temperature. Indications where found at the wheel inlet, ported shroud, and wheel outlet interfaces. The indications were only found for the two lower rotational speeds of the compressor wheel. To capture the behaviour on higher rotational speeds, more design points in the region of surge are needed, or transient simulations. Part three of the thesis project consisted of investigating the methodology of performing a Conjugate Heat Transfer model (CHT) with the CFD code CFX. This part has not been performed by Scania before, so a big part of the problem was to investigate if it actually was achievable. The goal was to use this model to calculate the heat transfer between fluid and solid parts, as well as between the solid parts and the ambient. One question Scania wanted to answer was if the CHT model could generate aerodynamic performance that corresponds to Scania's traditional adiabatic model, as well as to experimental data of the compressor. In this part, both solid and fluid domains were included in the geometryto calculate heat transport, in contrast to the traditional adiabatic model that only uses the fluid domains. Because of that, a big part of the work consisted of defining all interfaces connecting together surfaces between all domains. This is needed to model heat transport between the domains. In the set up part in CFX, the CHT model differed a lot from the traditional adiabatic model in that way that the outer walls was not set up as adiabatic anymore. In the CHT model, instead heat transfer is allowed between the outer walls of the fluids and the solids. From the result simulations, one could see that the CHT model was able to compute the heat transfer between fluids and solids. It also managed to export thermal data such as heat flux and wall heat transfer coefficient to be used for mechanical analysis, which is an important part in Scania's work. From the analysis of aerodynamic performance, a conclusion was drawn that the CHT model was able to compute efficiency and pressure ratio that followed the behaviour ofthe traditional adiabatic model as well as experimental data. However, for lowermass flows, the CHT model started to underpredict which could be explained by the geometrical differences between the CHT and adiabatic model. By analysis of temperature, one could see quantitative differences compared to the traditional adiabatic model. For other parameters (static and total pressure), there were no experimental data to be used for comparison. Because of that, an important part in future work of this CHT method development is to perform more experimental test for CFD data to be compared against. Another important part to compare the models is to have an identical geometry. Without an identical geometry, deviations in result will occur that depends on geometry.