Dissertations / Theses on the topic 'Computational methods in fluid flow'
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Zeybek, Birol. "Numerical simulation of flow induced by a spinning sphere using spectral methods." Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1997. http://handle.dtic.mil/100.2/ADA331206.
Full textPitman, Mark William. "An investigation of flow structure interactions on a finite compliant surface using computational methods." Thesis, Curtin University, 2007. http://hdl.handle.net/20.500.11937/625.
Full textRudgyard, Michael A. "Cell vertex methods for compressible gas flows." Thesis, University of Oxford, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.279991.
Full textRobbins, David James. "Development of computational fluid dynamics methods for low-speed flows." Thesis, University of Cambridge, 2014. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.708407.
Full textMazHer, A. Hamid K. "A computational method for three dimensional, internal viscous flows with separation and secondary flow patterns." Diss., Georgia Institute of Technology, 1987. http://hdl.handle.net/1853/12338.
Full textPitman, Mark William. "An investigation of flow structure interactions on a finite compliant surface using computational methods." Curtin University of Technology, Department of Mechanical Engineering, 2007. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=17209.
Full textTwo numerical modelling techniques are adopted to approach the analysis of the FSI system. A potential-flow method is used for the modelling of flows in the limit of infinite Reynolds numbers, while a grid-free Discrete Vortex Method (DVM) is used for the modelling of the rotational boundary-layer flow at moderate Reynolds numbers. In both inviscid and viscous studies, significant contributions are made to the numerical modelling techniques. The application of these methods to the study of flow over compliant panels gives new insight to the nature of the FSI system. In the linear inviscid model, a novel hybrid computational/theoretical method is developed that evaluates the eigenvalues and eigenmodes from a discretised FSI system. The results from the non-linear inviscid model revealed that the steady-state of the non-linear wall motion is independent of initial excitation. For the viscous case, the first application of a DVM to model the interaction of a viscous, rotational flow with a compliant surface is developed. This DVM is successfully applied to model boundary-layer flow over a finite compliant surface.
Gariba, Munir Antonio. "Visualisation methods for the analysis of blood flow using magnetic resonance imaging and computational fluid dynamics." Thesis, Imperial College London, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.322530.
Full textPeña, Monferrer Carlos. "Computational fluid dynamics multiscale modelling of bubbly flow. A critical study and new developments on volume of fluid, discrete element and two-fluid methods." Doctoral thesis, Universitat Politècnica de València, 2017. http://hdl.handle.net/10251/90493.
Full textEl estudio y modelado de flujos bifásicos, incluso los más simples como el bubbly flow, sigue siendo un reto que conlleva aproximarse a los fenómenos físicos que lo rigen desde diferentes niveles de resolución espacial y temporal. El uso de códigos CFD (Computational Fluid Dynamics) como herramienta de modelado está muy extendida y resulta prometedora, pero hoy por hoy, no existe una única aproximación o técnica de resolución que permita predecir la dinámica de estos sistemas en los diferentes niveles de resolución, y que ofrezca suficiente precisión en sus resultados. La dificultad intrínseca de los fenómenos que allí ocurren, sobre todo los ligados a la interfase entre ambas fases, hace que los códigos de bajo o medio nivel de resolución, como pueden ser los códigos de sistema (RELAP, TRACE, etc.) o los basados en aproximaciones 3D TFM (Two-Fluid Model) tengan serios problemas para ofrecer resultados aceptables, a no ser que se trate de escenarios muy conocidos y se busquen resultados globales. En cambio, códigos basados en alto nivel de resolución, como los que utilizan VOF (Volume Of Fluid), requirieren de un esfuerzo computacional tan elevado que no pueden ser aplicados a sistemas complejos. En esta tesis, mediante el uso de la librería OpenFOAM se ha creado un marco de simulación de código abierto para analizar los escenarios desde niveles de resolución de microescala a macroescala, analizando las diferentes aproximaciones, así como la información que es necesaria aportar en cada una de ellas, para el estudio del régimen de bubbly flow. En la primera parte se estudia la dinámica de burbujas individuales a un alto nivel de resolución mediante el uso del método VOF (Volume Of Fluid). Esta técnica ha permitido obtener resultados precisos como la formación de la burbuja, velocidad terminal, camino recorrido, estela producida por la burbuja e inestabilidades que produce en su camino. Pero esta aproximación resulta inviable para entornos reales con la participación de más de unas pocas decenas de burbujas. Como alternativa, se propone el uso de técnicas CFD-DEM (Discrete Element Methods) en la que se representa a las burbujas como partículas discretas. En esta tesis se ha desarrollado un nuevo solver para bubbly flow en el que se han añadido un gran número de nuevos modelos, como los necesarios para contemplar los choques entre burbujas o con las paredes, la turbulencia, la velocidad vista por las burbujas, la distribución del intercambio de momento y masas con el fluido en las diferentes celdas por cada una de las burbujas o la expansión de la fase gaseosa entre otros. Pero también se han tenido que incluir nuevos algoritmos como el necesario para inyectar de forma adecuada la fase gaseosa en el sistema. Este nuevo solver ofrece resultados con un nivel de resolución superior a los desarrollados hasta la fecha. Siguiendo con la reducción del nivel de resolución, y por tanto los recursos computacionales necesarios, se efectúa el desarrollo de un solver tridimensional de TFM en el que se ha implementado el método QMOM (Quadrature Method Of Moments) para resolver la ecuación de balance poblacional. El solver se desarrolla con los mismos modelos de cierre que el CFD-DEM para analizar los efectos relacionados con la pérdida de información debido al promediado de las ecuaciones instantáneas de Navier-Stokes. El análisis de resultados de CFD-DEM permite determinar las discrepancias encontradas por considerar los valores promediados y el flujo homogéneo de los modelos clásicos de TFM. Por último, como aproximación de nivel de resolución más bajo, se investiga el uso uso de códigos de sistema, utilizando el código RELAP5/MOD3 para analizar el modelado del flujo en condiciones de bubbly flow. El código es modificado para reproducir correctamente el flujo bifásico en tuberías verticales, comparando el comportamiento de aproximaciones para el cálculo del término d
L'estudi i modelatge de fluxos bifàsics, fins i tot els més simples com bubbly flow, segueix sent un repte que comporta aproximar-se als fenòmens físics que ho regeixen des de diferents nivells de resolució espacial i temporal. L'ús de codis CFD (Computational Fluid Dynamics) com a eina de modelatge està molt estesa i resulta prometedora, però ara per ara, no existeix una única aproximació o tècnica de resolució que permeta predir la dinàmica d'aquests sistemes en els diferents nivells de resolució, i que oferisca suficient precisió en els seus resultats. Les dificultat intrínseques dels fenòmens que allí ocorren, sobre tots els lligats a la interfase entre les dues fases, fa que els codis de baix o mig nivell de resolució, com poden ser els codis de sistema (RELAP,TRACE, etc.) o els basats en aproximacions 3D TFM (Two-Fluid Model) tinguen seriosos problemes per a oferir resultats acceptables , llevat que es tracte d'escenaris molt coneguts i se persegueixen resultats globals. En canvi, codis basats en alt nivell de resolució, com els que utilitzen VOF (Volume Of Fluid), requereixen d'un esforç computacional tan elevat que no poden ser aplicats a sistemes complexos. En aquesta tesi, mitjançant l'ús de la llibreria OpenFOAM s'ha creat un marc de simulació de codi obert per a analitzar els escenaris des de nivells de resolució de microescala a macroescala, analitzant les diferents aproximacions, així com la informació que és necessària aportar en cadascuna d'elles, per a l'estudi del règim de bubbly flow. En la primera part s'estudia la dinàmica de bambolles individuals a un alt nivell de resolució mitjançant l'ús del mètode VOF. Aquesta tècnica ha permès obtenir resultats precisos com la formació de la bambolla, velocitat terminal, camí recorregut, estela produida per la bambolla i inestabilitats que produeix en el seu camí. Però aquesta aproximació resulta inviable per a entorns reals amb la participació de més d'unes poques desenes de bambolles. Com a alternativa en aqueix cas es proposa l'ús de tècniques CFD-DEM (Discrete Element Methods) en la qual es representa a les bambolles com a partícules discretes. En aquesta tesi s'ha desenvolupat un nou solver per a bubbly flow en el qual s'han afegit un gran nombre de nous models, com els necessaris per a contemplar els xocs entre bambolles o amb les parets, la turbulència, la velocitat vista per les bambolles, la distribució de l'intercanvi de moment i masses amb el fluid en les diferents cel·les per cadascuna de les bambolles o els models d'expansió de la fase gasosa entre uns altres. Però també s'ha hagut d'incloure nous algoritmes com el necessari per a injectar de forma adequada la fase gasosa en el sistema. Aquest nou solver ofereix resultats amb un nivell de resolució superior als desenvolupat fins la data. Seguint amb la reducció del nivell de resolució, i per tant els recursos computacionals necessaris, s'efectua el desenvolupament d'un solver tridimensional de TFM en el qual s'ha implementat el mètode QMOM (Quadrature Method Of Moments) per a resoldre l'equació de balanç poblacional. El solver es desenvolupa amb els mateixos models de tancament que el CFD-DEM per a analitzar els efectes relacionats amb la pèrdua d'informació a causa del promitjat de les equacions instantànies de Navier-Stokes. L'anàlisi de resultats de CFD-DEM permet determinar les discrepàncies ocasionades per considerar els valors promitjats i el flux homogeni dels models clàssics de TFM. Finalment, com a aproximació de nivell de resolució més baix, s'analitza l'ús de codis de sistema, utilitzant el codi RELAP5/MOD3 per a analitzar el modelatge del fluxos en règim de bubbly flow. El codi és modificat per a reproduir correctament les característiques del flux bifàsic en canonades verticals, comparant el comportament d'aproximacions per al càlcul del terme de drag basades en velocitat de drift flux model i de les basades en coe
Peña Monferrer, C. (2017). Computational fluid dynamics multiscale modelling of bubbly flow. A critical study and new developments on volume of fluid, discrete element and two-fluid methods [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/90493
TESIS
Izard, Edouard. "Modélisation numérique des écoulements granulaires denses immergés dans un fluide." Phd thesis, Toulouse, INPT, 2014. http://oatao.univ-toulouse.fr/12186/1/izard.pdf.
Full textRoberge, Jennifer Anne. "Use of Computational Fluid Dynamics (CFD) to Model Flow at Pump Intakes." Digital WPI, 1999. https://digitalcommons.wpi.edu/etd-theses/1046.
Full textFairchilds, William Landrum. "NEW WALL FUNCTION METHODS FOR USE WITH COARSE NEAR-WALL MESHES IN TURBULENT FLOW COMPUTATIONAL FLUID DYNAMICS SIMULATIONS." MSSTATE, 2007. http://sun.library.msstate.edu/ETD-db/theses/available/etd-07052007-125941/.
Full textYun, Brian Min. "Simulations of pulsatile flow through bileaflet mechanical heart valves using a suspension flow model: to assess blood damage." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/53378.
Full textFrom, Christopher. "High-order lattice Boltzmann for nonideal fluid mixtures." Thesis, Queensland University of Technology, 2020. https://eprints.qut.edu.au/200190/1/Christopher_From_Thesis.pdf.
Full textRahimian, Abtin. "Parallel algorithms for direct blood flow simulations." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/43611.
Full textMacFadden, James. "Computational methods for incompressible fluid flows, with reference to interface modelling by an extended finite element method." Thesis, Swansea University, 2006. https://cronfa.swan.ac.uk/Record/cronfa42810.
Full textKupiainen, Marco. "Compressible Turbulent Flows : LES and Embedded Boundary Methods." Doctoral thesis, KTH, Numerisk analys, NA, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-10090.
Full textCelestin, Carey Jr. "Computational Fluid Dynamics Applied to the Analysis of Blood Flow Through Central Aortic to Pulmonary Artery Shunts." ScholarWorks@UNO, 2015. http://scholarworks.uno.edu/td/1972.
Full textGryngarten, Leandro Damian. "Multi-phase flows using discontinuous Galerkin methods." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/45824.
Full textCai, Shang-Gui. "Computational fluid-structure interaction with the moving immersed boundary method." Thesis, Compiègne, 2016. http://www.theses.fr/2016COMP2276/document.
Full textIn this thesis a novel non-body conforming mesh formulation is developed, called the moving immersed boundary method (MIBM), for the numerical simulation of fluid-structure interaction (FSI). The primary goal is to enable solids of complex shape to move arbitrarily in an incompressible viscous fluid, without fitting the solid boundary motion with dynamic meshes. This novel method enforces the no-slip boundary condition exactly at the fluid-solid interface with a boundary force, without introducing any artificial constants to the rigid body formulation. As a result, large time step can be used in current method. To determine the boundary force more efficiently in case of moving boundaries, an additional moving force equation is derived and the resulting system is solved by the conjugate gradient method. The proposed method is highly portable and can be integrated into any fluid solver as a plug-in. In the present thesis, the MIBM is implemented in the fluid solver based on the projection method. In order to obtain results of high accuracy, the rotational incremental pressure correction projection method is adopted, which is free of numerical boundary layer and is second order accurate. To accelerate the calculation of the pressure Poisson equation, the multi-grid method is employed as a preconditioner together with the conjugate gradient method as a solver. The code is further parallelized on the graphics processing unit (GPU) with the CUDA library to enjoy high performance computing. At last, the proposed MIBM is applied to the study of two-way FSI problem. For stability and modularity reasons, a partitioned implicit scheme is selected for this strongly coupled problem. The interface matching of fluid and solid variables is realized through a fixed point iteration. To reduce the computational cost, a novel efficient coupling scheme is proposed by removing the time-consuming pressure Poisson equation from this fixed point interaction. The proposed method has shown a promising performance in modeling complex FSI system
Cureton, Christopher Wayne. "The implementation of four additional inviscid flux methods in the U²NCLE parallel unstructured Navier-Stokes solver." Master's thesis, Mississippi State : Mississippi State University, 2007. http://library.msstate.edu/etd/show.asp?etd=etd-04032007-221145.
Full textEl-Ibrahim, Salah Jamil Saleh. "Prediction of the effects of aerofoil surface irregularities at high subsonic speeds using the Viscous Garabedian and Korn (VKG) method." Thesis, University of Hertfordshire, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.365928.
Full textTai, Anna On-No. "Simulating flow around deforming bodies with an element boundary method." Thesis, University of Bath, 2009. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.524058.
Full textGao, Haotian. "POD-Galerkin based ROM for fluid flow with moving boundaries and the model adaptation in parametric space." Diss., Kansas State University, 2018. http://hdl.handle.net/2097/38776.
Full textDepartment of Mechanical and Nuclear Engineering
Mingjun Wei
In this study, a global Proper Orthogonal Decomposition (POD)-Galerkin based Reduced Order model (ROM) is proposed. It is extended from usual fixed-domain problems to more general fluid-solid systems with moving boundaries/interfaces. The idea of the extension is similar to the immersed boundary method in numerical simulations which uses embedded forcing terms to represent boundary motions and domain changes. This immersed boundary method allows a globally defined fixed domain including both fluid and solid, where POD-Galerkin projection can be directly applied. However, such a modified approach cannot get away with the unsteadiness of boundary terms which appear as time-dependent coefficients in the new Galerkin model. These coefficients need to be pre-computed for prescribed periodic motion, or worse, to be computed at each time step for non-prescribed (e.g. with fluid-structure interaction) or non-periodic situations. Though computational time for each unsteady coefficient is smaller than the coefficients in a typical Galerkin model, because the associated integration is only in the close neighborhood of moving boundaries. The time cost is still much higher than a typical Galerkin model with constant coefficients. This extra expense for moving-boundary treatment eventually undermines the value of using ROMs. An aggressive approach is to decompose the moving boundary/domain to orthogonal modes and derive another low-order model with fixed coefficients for boundary motion. With this domain decomposition, an approach including two coupled low-order models both with fixed coefficients is proposed. Therefore, the new global ROM with decomposed approach is more efficient. Though the model with the domain decomposition is less accurate at the boundary, it is a fair trade-off for the benefit on saving computational cost. The study further shows, however, that the most time-consuming integration in both approaches, which come from the unsteady motion, has almost negligible impact on the overall dynamics. Dropping these time-consuming terms reduces the computation cost by at least one order while having no obvious effect on model accuracy. Based on this global POD-Galerkin based ROM with forcing term, an improved ROM which can handle the parametric variation of body motions in a certain range is also presented. This study shows that these forcing terms not only represent the moving of the boundary, but also decouple the moving parameters from the computation of model coefficients. The decoupling of control parameters provides the convenience to adapt the model for the prediction on states under variation of control parameters. An improved ROM including a shit mode seems promising in model adaptation for typical problems in a fixed domain. However, the benefit from adding a shit mode to model diminishes when the method is applied to moving-boundary problems. Instead, a combined model, which integrates data from a different set of parameters to generate the POD modes, provides a stable and accurate ROM in a certain range of parametric space for moving-boundary problems. By introducing more data from a different set of parameters, the error of the new model can be further reduced. This shows that the combined model can be trained by introducing more and more information. With the idea of the combined model, the improved global ROM with forcing terms shows impressive capability to predict problems with different unknown moving parameters, and can be used in future parametric control and optimization problems.
Katamine, Eiji, Hideyuki Azegami, and Akiyoshi Okitsu. "Shape Optimization Analysis of Flow Field : Growth-Strain Method Approach." 日本機械学会, 1994. http://hdl.handle.net/2237/12157.
Full textThorne, Jonathan L. "Extensions of High-order Flux Correction Methods to Flows With Source Terms at Low Speeds." DigitalCommons@USU, 2015. https://digitalcommons.usu.edu/etd/4594.
Full textMakgata, Katlego Webster. "Computational analysis and optimisation of the inlet system of a high-performance rally engine." Diss., Pretoria : [s.n.], 2005. http://upetd.up.ac.za/thesis/available/etd-01242006-123639.
Full textBoukanga, Noel Rupert Thierry. "Three dimensional modelling of generalized Newtonian fluids in domains including obstructions." Thesis, Loughborough University, 2010. https://dspace.lboro.ac.uk/2134/6936.
Full textMyers, Alexandra. "A computational study of the effect of cross wind on the flow of fire fighting agent." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2004. http://library.nps.navy.mil/uhtbin/hyperion/04Jun%5FMyers.pdf.
Full textÅkerberg, Andreas. "CFD analyses of the gas flow inside the vessel of a hot isostatic press." Thesis, KTH, Kraft- och värmeteknologi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-101168.
Full textShcherbakov, Victor. "Localised Radial Basis Function Methods for Partial Differential Equations." Doctoral thesis, Uppsala universitet, Avdelningen för beräkningsvetenskap, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-332715.
Full textMacLean, Matthew. "A Numerical Study of Internal Flow Effects on Skin Friction Gages." Diss., Virginia Tech, 2002. http://hdl.handle.net/10919/27114.
Full textPh. D.
Stewart, Dawn L. "Numerical Methods for Accurate Computation of Design Sensitivities." Diss., Virginia Tech, 1998. http://hdl.handle.net/10919/30561.
Full textPh. D.
Mokos, Athanasios Dorotheos. "Multi-phase modelling of violent hydrodynamics using Smoothed Particle Hydrodynamics (SPH) on Graphics Processing Units (GPUs)." Thesis, University of Manchester, 2014. https://www.research.manchester.ac.uk/portal/en/theses/multiphase-modelling-of-violent-hydrodynamics-using-smoothed-particle-hydrodynamics-sph-on-graphics-processing-units-gpus(a82b8187-f81a-400b-8bd2-9a74c502a953).html.
Full textKoc, Gencer. "Simulation Of Flow Transients In Liquid Pipeline Systems." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/2/12609018/index.pdf.
Full text, Genç
er M.S., Department of Mechanical Engineering Supervisor: Prof. Dr. O. Cahit Eralp November 2007, 142 pages In liquid pipeline systems, transient flow is the major cause of pipeline damages. Transient flow is a situation where the pressure and flow rate in the pipeline rapidly changes with time. Flow transients are also known as surge and Waterhammer which originates from the hammering sound of the water in the taps or valves. In liquid pipelines, preliminary design parameters are chosen for steady state operations, but a transient check is always necessary. There are various types of transient flow situations such as valve closures, pump trips and flow oscillations. During a transient flow, pressure inside the pipe may increase or decrease in an unexpected way that cannot be foreseen by a steady state analysis. Flow transients should be considered by a complete procedure that simulates possible transient flow scenarios and by the obtained results, precautions should be taken. There are different computational methods that can be used to solve and simulate flow transients in computer environment. All computational methods utilize basic v flow equations which are continuity and momentum equations. These equations are nonlinear differential equations and some mathematical tools are necessary to make these equations linear. In this thesis a computer program is coded that utilizes &ldquo
Method of Characteristics&rdquo
which is a numerical method in solving partial differential equations. In pipeline hydraulics, two partial differential equations, continuity and momentum equations are solved together, in order to obtain the pressure and flow rate values in the pipeline, during transient flow. In this thesis, MATLAB 7.1 is used as the programming language and obtained code is converted to a C# language to be able to integrate the core of the program with a user friendly Graphical User Interface (GUI). The Computer program is verified for different scenarios with the available real pipeline data and results of various reputable agencies. The output of the computer program is the tabulated pressure and flow rate values according to time indexes and graphical representations of these values. There are also prompts for users warning about possible dangerous operation modes of the pipeline components.
Sjölund, Johannes. "Real-time Thermal Flow Predictions for Data Centers : Using the Lattice Boltzmann Method on Graphics Processing Units for Predicting Thermal Flow in Data Centers." Thesis, Luleå tekniska universitet, Institutionen för system- och rymdteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-70530.
Full textGuarendi, Andrew N. "Numerical Investigations of Magnetohydrodynamic Hypersonic Flows." University of Akron / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=akron1365985409.
Full textRajaguru, Mudiyanselage Thilanki Maneesha Dahigamuwa. "Enhancement of Rainfall-Triggered Shallow Landslide Hazard Assessment at Regional and Site Scales Using Remote Sensing and Slope Stability Analysis Coupled with Infiltration Modeling." Scholar Commons, 2018. https://scholarcommons.usf.edu/etd/7562.
Full textSuo, Jin. "Investigation of blood flow patterns and hemodynamics in the human ascending aorta and major trunks of right and left coronary arteries using magnetic resonance imaging and computational fluid dynamics." Diss., Available online, Georgia Institute of Technology, 2005, 2005. http://etd.gatech.edu/theses/available/etd-01192005-121529/unrestricted/suo%5Fjin%5F200505%5Fphd.pdf.
Full textGiddens, P. Don, Committee Chair ; Vito, P. Raymond, Committee Member ; Taylor, Robert, W., Committee Member ; Oshinski, John, Committee Member ; Bao, Gang, Committee Member. Includes bibliographical references.
Volk, Annette. "Quantification of Numerical and Modeling Errors in Simulation of Fluid Flow through a Fixed Particle Bed." University of Cincinnati / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1448275079.
Full textVolk, Annette. "Quantification and Assessment of Numerical Error in Coupled Computational Fluid Dynamics - Discrete Element Method Simulations of Gas Flow through Granular Solids." University of Cincinnati / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1543139366302536.
Full textAmoignon, Olivier. "Numerical Methods for Aerodynamic Shape Optimization." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-6252.
Full textBourg, David M. "Development of the Distributed Points Method with Application to Cavitating Flow." ScholarWorks@UNO, 2008. http://scholarworks.uno.edu/td/904.
Full textKilimnik, Alexander. "Cross stream migration of compliant capsules in microfluidic channels." Thesis, Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/43669.
Full textSerson, Douglas. "Numerical study of wings with wavy leading and trailing edges." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/3/3150/tde-03032017-110359/.
Full textInspirado na nadadeira peitoral da baleia jubarte, o uso de ondulações ao longo da envergadura de asas tem sido considerado na literatura como uma possível maneira de atrasar o estol, e possivelmente também reduzir o arrasto, levando a melhores características aerodinâmicas. Com o objetivo de obter um melhor entendimento desse mecanismo de controle do escoamento, o presente trabalho investiga numericamente o efeito de ondulações no escoamento ao redor de asas infinitas com o perfil NACA0012. O estudo consiste de simulações diretas do escoamento usando o método espectral/hp, que está disponível através da biblioteca nektar++. Considerando o alto custo computacional das simulações realizadas, diversas melhorias foram introduzidas no método, tornando-o mais eficiente e permitindo que números de Reynolds mais elevados fossem analisados. Essas melhorias ao método incluem uma técnica de mudança de coordenadas para tratar a ondulação, mudanças na estratégia de paralelismo e um procedimento de refinamento usando ordem polinomial variável. Inicialmente, simulações foram realizadas para um número de Reynolds muito baixo Re = 1, 000, o que permitiu observar as estruturas tridimensionais do escoamento em detalhe. Nesse caso, os resultados mostram que a ondulação leva a uma diminuição da razão sustentação-arrasto, combinada com uma forte redução das flutuações da força de sustentação. A redução da razão sustentação-arrasto é consequência de uma combinação de arrasto e sustentação mais baixos e está associada a um regime no qual o escoamento permanece colado atrás dos picos do bordo de ataque, enquanto que regiões distintas de escoamento separado estão presentes atrás dos vales. Em seguida, simulações com Re = 10, 000 foram consideradas. Para ângulos de ataque elevados, os resultados neste caso são similares àqueles com Re mais baixo, com a ondulação levando a separação atrás dos vales e provocando reduções na sustentação e no arrasto. No entanto, para um ângulo de ataque mais baixo a ondulação leva a um grande aumento na força de sustentação. Foi observado que isso está relacionado ao fato de que o escoamento ao redor da asa lisa é laminar neste caso, com a ondulação induzindo a transição para um estado turbulento. Finalmente, o caso Re = 50, 000 foi considerado, com os resultados apresentando uma boa concordância com experimentos apresentados na literatura.
Ravikumar, Devaki. "2D Compressible Viscous Flow Computations Using Acoustic Flux Vector Splitting (AFVS) Scheme." Thesis, Indian Institute of Science, 2001. http://hdl.handle.net/2005/277.
Full textPretorius, Johannes Jacobus. "A network approach for the prediction of flow and flow splits within a gas turbine combustor." Diss., University of Pretoria, 2005. http://hdl.handle.net/2263/26712.
Full textDissertation (MEng (Mechanical Engineering))--University of Pretoria, 2005.
Mechanical and Aeronautical Engineering
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Vanon, Riccardo. "Zonal flows in accretion discs and their role in gravito-turbulence." Thesis, University of Cambridge, 2017. https://www.repository.cam.ac.uk/handle/1810/267991.
Full textSuzuki, Kosuke. "An immersed boundary-lattice Boltzmann method for moving boundary flows and its application to flapping flight." 京都大学 (Kyoto University), 2014. http://hdl.handle.net/2433/188584.
Full textHodapp, Maximilian Joachim. "Modelagem e simulação de um leito fluidizado : um estudo comparativo." [s.n.], 2009. http://repositorio.unicamp.br/jspui/handle/REPOSIP/266452.
Full textDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica
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Resumo: O objetivo deste trabalho foi o estudo comparativo de duas modelagens para representação de um escoamento gás-sólido. Na primeira modelagem avaliou-se uma correlação de arraste apresentada recentemente na literatura, baseada em simulações lattice Boltzmann, aplicada a escoamentos gás-sólido. Na segunda observou-se o efeito da variação do coeficiente de especularidade na condição de contorno na parede sobre os perfis de velocidade da fase particulada. Grande atenção tem sido dada a modelagem matemática de escoamentos multifásicos, em especial ao gás-sólido, uma vez que vários processos industriais utilizam-se desta operação. Porém o desenvolvimento de modelos analíticos que incluam todos os fenômenos de transferência de massa, energia e quantidade de movimento não encontra-se disponível, devido principalmente a grande complexidade dos fenômenos envolvidos. Neste aspecto a fluidodinâmica computacional (CFD) tem demonstrado ser uma boa alternativa para o estudo de sistemas complexos, sendo diversos estudos, não somente de engenharia, aplicando esta técnica, publicados todos os anos. Como forma de validar os resultados obtidos por este método numérico, escolheu-se um caso de estudo em escala de laboratório. Os softwares comerciais ANSYS CFX 10 e FLUENT 6.3 foram utilizados para a definição e resolução do problema, além do pós-processamento. Os resultados obtidos foram comparados com os dados numéricos de um trabalho de mestrado do PQGe, bem como com dados experimentais da literatura. Pode-se perceber que os resultados, para a primeira abordagem não apresentaram melhoras em relação a outras modelagens das forças entre e intra-partículas, além do maior tempo computacional requerido. A segunda abordagem demonstrou valores adequados para o coeficiente estudado
Abstract: The aim of this work was a comparative study of two different modeling to represent a gas-solid flow. The first approach consists of a new drag correlation presented in the literature. This relation was obtained through lattice Boltzmann simulations of gas-solid flow, thus not depending on empirical data. The second looked for the effects of the variation of the specularity coefficient at the wall boundary condition. Multiphase flow modeling is gathering great attention, especially to gas-solid flows, due to its importance in industrial processes. However analytical models that take into account the mass, momentum and energy transfers are not available, mainly because of the complexities evolved in such systems. Therefore Computational Fluid Dynamics (CFD) has proved to be a viable alternative, having a large number of scientific works been published in recent years. In order to validate the results a comparison with other simulations using different modeling, done by another member of the PQGe laboratory, and with experimental data was carried out. The commercial softwares ANSYS CFX 10 and FLUENT 6.3 were used to define and numerically solve the problem, also to post process the results. For the first approach, the comparison showed that the studied drag correlation gave no improvement upon the other two models analyzed. Also a longer computational time was required, which can not be ignored as an important parameter in CFD simulations. As for the second approach, it was possible to obtain adequate values for the specularity coefficient
Mestrado
Desenvolvimento de Processos Químicos
Mestre em Engenharia Química
YAMAMOTO, Kazuhiro, and 和弘 山本. "メタルハニカム内のディーゼル微粒子燃焼シミュレーション." 一般社団法人 日本機械学会, 2008. http://hdl.handle.net/2237/19798.
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