Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 16 of 16
Full-Text Articles in Entire DC Network
Numerical Simulations Of Supersonic/ Hypersonic Flows In Compression Corners And A Hypersonic Flow Study Of Atmospheric Entry Of Mars Science Laboratory Capsule, Dexter Allen
McKelvey School of Engineering Theses & Dissertations
This thesis consists of two related parts. The first part is the study of supersonic/hypersonic flow in compression corners. The compression corners are simple geometries but rich in flow-features that can be challenging for accurate prediction of their flow fields in high-speed compressible flow using the Reynold-Averaged Navier-Stokes (RANS) equations in conjunction with a turbulence model. At higher degrees of corner angles, there exists a shock-boundary layer interaction region which includes a significant recirculation zone in the corner. In this thesis, experimentally available test cases for compression corner at Mach 3, 8, and 11 at various corner angles are modeled …
Computational Analysis Of Steady Hypersonic Flow Fields Of Nasa Benchmark Geometries Utilizing Ansys Fluent, Aidan Murphy
Computational Analysis Of Steady Hypersonic Flow Fields Of Nasa Benchmark Geometries Utilizing Ansys Fluent, Aidan Murphy
McKelvey School of Engineering Theses & Dissertations
The Hypersonic International Flight Research Experimentation (HIFiRE) program explores and advances hypersonic aerospace systems by developing a multitude of test flight geometries and conducting experimental test flights to obtain data for use in validation of computational models and results. This study focuses on computational validation of heat flux, and calculation of static pressure profiles, skin friction coefficient profiles, and flow contours. The flow fields studied are for Mach number 7.18 and angles of attack (α) of 0° & 2°. These flow fields include many compressible flow features such as an expansion wave at the intersection of the cone and flat …
Computational Fluid Dynamics Modeling Of Hemodialysis In Patients With An Arteriovenous Fistula, Maximilian Roth
Computational Fluid Dynamics Modeling Of Hemodialysis In Patients With An Arteriovenous Fistula, Maximilian Roth
McKelvey School of Engineering Theses & Dissertations
With the advent of arteriovenous fistula (AVF) for use in hemodialysis, the anastomosis built for such use has become a central point of the study to understand the flow and wall shear stresses in such a system since very large wall shear stresses can lead to arterial/vein rupture. Considering the commonly used creation site of an anastomosis as connecting the radial artery to the cephalic vein, a model is created to calculate the wall shear stresses across various components of the system. The model depicts a connection of the specified vein and artery bridged together allowing the increase in blood …
Computational Fluid Dynamics And Fluid Structure Interaction Research On Flow In A Glenn Shunt And A Flexible Tube And On A Cantilevered Plate, Chunhui Wang
McKelvey School of Engineering Theses & Dissertations
This thesis employs Computational Fluid Dynamics (CFD) simulation technology to solve three flow problems: (1) Blood flow in a Bidirectional Glenn Shunt and a combined Bidirectional Glenn Shunt (BGS) and Blalock-Taussing (BT) Shunt. This shunt is used to address the problem of Cyanosis or “Blue Baby Syndrome,” which is an infant disorder that affects the newly born babies whose skins turn blue or purple because of lack of necessary blood flow between heart and lung due to pulmonary vascular blockage. The goal of this study was to evaluate the performance of BGS and combined BGS+BT shunt in achieving the desired …
Development And Application Of Rotation And Curvature Correction To Wray-Agarwal Turbulence Model, Xiao Zhang
Development And Application Of Rotation And Curvature Correction To Wray-Agarwal Turbulence Model, Xiao Zhang
McKelvey School of Engineering Theses & Dissertations
Computational Fluid Dynamics (CFD) is increasingly playing a significant role in the analysis and design of aircrafts, turbomachines, automobiles, and in many other industrial applications. In majority of the applications, the fluid flow is generally turbulent. The accurate prediction of turbulent flows to date remains a challenging problem in CFD. In almost all industrial applications, Reynolds-Averaged Navier-Stokes (RANS) equations in conjunction with a turbulence model are employed for simulation and prediction of turbulent flows. Currently the one-equation (namely the Spalart-Allmaras (SA) and Wray-Agarwal (WA) and two-equation (namely the k-ε and Shear Stress Transport k-ω) turbulence models remain the most widely …
Validation Of Cfd Simulations For Hypersonic Flow Over A Yawed Cone, Julian Cecil
Validation Of Cfd Simulations For Hypersonic Flow Over A Yawed Cone, Julian Cecil
McKelvey School of Engineering Theses & Dissertations
This study aims to numerically simulate the wind tunnel results for hypersonic flow over a circular cone of semi-apex angle of 10 degrees yawed from 0° to 20° using the commercial computational fluid dynamics software ANSYS Fluent. The ANSYS workbench is used to create the 10° semi-apex circular cone with a shock aligned structured mesh of 3.05 million cells surrounding the cone. Simulation boundary conditions for pressure and temperature in the far field correspond to Tracy’s wind tunnel experiment at Cal Tech. The six simulations cases are conducted for yaw angles of 0, 8, 12, 16, 20 and 24 degrees. …
Cfd Performance Of Turbulence Models For Flow From Supersonic Nozzle Exhausts, Han Ju Lee
Cfd Performance Of Turbulence Models For Flow From Supersonic Nozzle Exhausts, Han Ju Lee
McKelvey School of Engineering Theses & Dissertations
The goal of this thesis is to compare the performance of several eddy-viscosity turbulence models for computing supersonic nozzle exhaust flows. These flows are of relevance in the development of future supersonic transport airplane. Flow simulations of exhaust flows from three supersonic nozzles are computed using ANSYS Fluent. Simulation results are compared to experimental data to assess the performance of various one- and two-equation turbulence models for accurately predicting the supersonic plume flow. One particular turbulence model of interest is the Wray-Agarwal (WA) turbulence model. This is a neat model which has demonstrated promising results mimicking the strength of two …
Numerical Drag Prediction Of Nasa Common Research Models Using Different Turbulence Models, Pan Du
Numerical Drag Prediction Of Nasa Common Research Models Using Different Turbulence Models, Pan Du
McKelvey School of Engineering Theses & Dissertations
The goal of this research is to perform 3D turbulence flow simulations to predict the drag of Wing-body-tail (WBT) and Wing-body-nacelle-Pylon (WBNP) aircraft configurations from NASA Common Research Models. These configurations are also part of the 4th and 6th AIAA Drag Prediction Workshops in which CFD modelers have participated worldwide. The computations are performed using CFD solver ANSYS FLUENT. The compressible Reynolds-Averaged Navier-Stokes (RANS) equations are solved using two turbulence models – the Spalart-Allmaras (SA) and SST k-ω. Drag polar and drag rise curves are obtained by performing computations at different angles of attack at a constant Mach number. Pressure …
Cfd Simulations Of Chemical Looping Combustion In A Packed Bed And A Bubbling Bed Fuel Reactor, Guanglei Ma
Cfd Simulations Of Chemical Looping Combustion In A Packed Bed And A Bubbling Bed Fuel Reactor, Guanglei Ma
McKelvey School of Engineering Theses & Dissertations
Chemical-looping combustion (CLC) is a next generation combustion technology that has shown great promise in addressing the need for high-efficiency low-cost carbon capture from fossil fueled power plants to address the rising carbon emissions. Although there have been a number of experimental studies on CLC in recent years, CFD simulations have been limited in the literature on CLC. The development and confidence in high-fidelity simulations of the CLC process is a necessary step towards facilitating the transition from laboratory-scale experiments to deployment of this technology on an industrial scale. In this research, first the CFD simulations of a CLC packed …
Numerical Study Of The Aerodynamics Of Dlr-F6 Wing-Body In Unbounded Flow Field And In Ground Effect, Ning Deng
Numerical Study Of The Aerodynamics Of Dlr-F6 Wing-Body In Unbounded Flow Field And In Ground Effect, Ning Deng
McKelvey School of Engineering Theses & Dissertations
The main focus of this thesis is on the simulation of flow past a three-dimensional wing-body configuration (DLR-F6) in ground effect; a complex 3D wing-body configuration in ground effect has never been analyzed in the aerodynamics literature to date. For the purpose of validation of the simulation approach, computations are performed for the DLR-F6 wing-body in unbounded flow and are compared with the experimental data. The commercial CFD solver ANSYS FLUENT is employed for computations. Compressible Reynolds-Averaged Navier-Stokes (RANS) equations in conjunction with Spalart-Allmaras (SA) and - Shear Stress Transport (SST) turbulence models are solved. The validated code is employed …
Development Of A One-Equation Eddy Viscosity Turbulence Model For Application To Complex Turbulent Flows, Timothy Wray
Development Of A One-Equation Eddy Viscosity Turbulence Model For Application To Complex Turbulent Flows, Timothy Wray
McKelvey School of Engineering Theses & Dissertations
Computational fluid dynamics (CFD) is routinely used in performance prediction and design of aircraft, turbomachinery, automobiles, and in many other industrial applications. Despite its wide range of use, deficiencies in its prediction accuracy still exist. One critical weakness is the accurate simulation of complex turbulent flows using the Reynolds-Averaged Navier-Stokes equations in conjunction with a turbulence model. The goal of this research has been to develop an eddy viscosity type turbulence model to increase the accuracy of flow simulations for mildly separated flows, flows with rotation and curvature effects, and flows with surface roughness. It is accomplished by developing a …
Cfd Simulation And Shape Optimization Of Supersonic Ejectors For Refrigeration And Desalination Applications, Liju Su
McKelvey School of Engineering Theses & Dissertations
The aim of this thesis is to investigate the detailed flow field inside the supersonic ejector using numerical methods and to optimize the ejector’s mixing chamber wall shape to obtain a maximum entrainment ratio (ER) in order to obtain the highest possible efficiency that can be attained by the ejector. A steam ejector applied in the cooling industry is first studied to determine the most accurate turbulence model for its supersonic jet flow field simulation with mixing with the entrained steam in the mixing chamber. A commercial Computational Fluid Dynamics (CFD) package FLUENT 14.5 along with the meshing tool ICEM …
Application Of Wray-Agarwal Model To Turbulent Flow In A 2d Lid-Driven Cavity And A 3d Lid-Driven Box, Hakop J. Nagapetyan
Application Of Wray-Agarwal Model To Turbulent Flow In A 2d Lid-Driven Cavity And A 3d Lid-Driven Box, Hakop J. Nagapetyan
McKelvey School of Engineering Theses & Dissertations
In this thesis, various turbulence models are used for simulating internal vortical flow, both turbulent and laminar, with large recirculation by considering the flow in a 2-D lid-driven square cavity and a 3-D lid driven cubic box. The accuracy of the newly developed Wray-Agarwal (WA) one equation turbulence model is compared against two well-known industry standard turbulence models; the Spalart-Allmaras (SA) and the Shear-Stress-Transport (SST) k-ω models. The simulations are performed by numerically solving the Reynolds-Averaged Navier-Stokes (RANS) equations in conjunction with WA, SA and SST k-ω models and comparing the results with the available experimental data and Large Eddy …
Optimization Of Blalock-Taussig Shunt And Anastomotic Geometry For Vascular Access Fistula Using A Genetic Algorithm, Guangyu Bao
Optimization Of Blalock-Taussig Shunt And Anastomotic Geometry For Vascular Access Fistula Using A Genetic Algorithm, Guangyu Bao
McKelvey School of Engineering Theses & Dissertations
Blalock-Taussig (BT) shunts are used for defects that affect the flow of blood from the right ventricle, through the pulmonary artery, and to the lungs. Arteriovenous (AV) fistula is one type of vascular access which is a surgically created vein used to remove and return blood during hemodialysis. Plastic grafts used in the above two reconstructions may result in areas of non-physiologic flow in the grafts leading to risk of stenosis (blocked area) and thrombosis, which is the single major cause for access morbidity. The focus of this thesis is to study BT shunts and anastomoses models using Computational Fluid …
Evaluation Of The Performance Of Various Turbulence Models For Accurate Numerical Simulation Of A 2d Slot Nozzle Ejector, Colin Graham
Evaluation Of The Performance Of Various Turbulence Models For Accurate Numerical Simulation Of A 2d Slot Nozzle Ejector, Colin Graham
McKelvey School of Engineering Theses & Dissertations
With the development over the last several decades, accurate Computational Fluid Dynamics (CFD) modeling has now become an essential part in the analysis and design of various industrial products where the fluid flow plays an important role. The goal of this thesis is to apply the CFD technology to the analysis of a 2D slot nozzle ejector which has application in Short Take-off and Landing (STOL) aircraft and other future aerospace vehicles. In the nozzle-ejector configuration, the high speed air flow from the nozzle entrains the ambient air into a mixing chamber (ejector) as a means to create additional thrust …
Numerical Simulation Of Separated And Secondary Flows In Diffusing S-Ducts For Air Breathing Propulsion, Colin James Fiola
Numerical Simulation Of Separated And Secondary Flows In Diffusing S-Ducts For Air Breathing Propulsion, Colin James Fiola
All Theses and Dissertations (ETDs)
No abstract provided.