Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 234 for “"Turbulence Model"”.
-
A modified Baldwin-Lomax turbulence model for turbomachinery wakes
A critical evaluation of the Baldwin-lomax (Bl) turbulence model for shock/shear layer interactions, reversed flow, and curved, asymmetric wakes is made. No general definition for reference line is available for wakes, and difficulties exist for length scale prediction in complex flows. An entropy …
-
A higher order closure turbulence model of the planetary boundary layer
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Meteorology, 1979.
-
Computation of Hypersonic Flows with Lateral Jets Using k-ω Turbulence Model
… conditions at 30km altitude. The k-w turbulent model is used to model the case. It is apparent from the results that the lateral jet reconstructs the flow field by pushing the conical shock away and creating a large recirculation zone in front of the blunt body. This pushes the reattachment …
-
Assessment of Hybrid CFD Turbulence Model, STRUCT-epsilon, for Thermal Striping Behavior
… by thermal striping, which presently accepted modeling and design tools are unable to accurately or reliably predict the presence of. Advanced reactors are vital in achieving net-zero carbon electricity production and thus developing design tools that can predict thermal striping is essential. …
-
Closure Modeling for Accelerated Multiscale Evolution of a 1-Dimensional Turbulence Model
Accelerating the simulation of turbulence to stationarity is a critical challenge in various engineering applications. This study presents an innovative equation-free multiscale approach combined with a machine learning technique to address this challenge in the context of the one-dimensional …
-
Development and Application of Rotation and Curvature Correction to Wray-Agarwal Turbulence Model
… (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 …
-
Development and Application of Hybrid Wray-Agarwal Turbulence Model and Large-Eddy Simulation
… equations in the industry. RANS methods require modeling of turbulence effect (i.e. turbulence modeling) based on empirical relations and therefore often produce low accuracy results for many flows. In recent years, the Large Eddy Simulation (LES) approach has been developed which has shown …
-
Computational fluid dynamics and turbulence model uncertainty quantification for nuclear reactor safety applications
… Emphasis is placed on the quantification of turbulence modeling uncertainty in a predictive context, as it is the clear missing link in the handling of CFD uncertainty. Previous work has commonly focused on the propagation of uncertainty due to turbulence model calibration coefficients, …
-
Application of a modified k-[epsilon] turbulence model to gas turbine combustor geometries
The k-epsilon turbulence model yields inconsistent and diffusive results for swirling and recirculating flows, which are characteristic of combustor geometries. Y. S. Chen and S. W. Kim propose a modification to the k-epsilon turbulence model which has shown improved predictions for several complex …
-
A turbulence model for steady and unsteady boundary layers in strong pressure gradients
A new turbulence model designed for two-dimensional, steady and unsteady boundary layers in strong adverse pressure gradients is described. The model is developed in a rational way based on an understanding of the flow physics obtained from recent experimental observations. The turbulent shear …
-
Extension to Multiple Species of a Two-Equation Turbulence Model for High Speed Flows
<p>The Wilcox (2006) <em>k-co </em>turbulence model has been extended to multiple species and implemented in a CFD code for high speed flows using the Steger-Warming flux-vector splitting scheme. The model was chosen because compressibility corrections are not required, nor are viscous damping …
-
Application of hybrid Computational Fluid Dynamics turbulence model, STRUCT-[epsilon], on heated flow cases
Computational Fluid Dynamics (CFD) modeling is a powerful numerical method that can be used to characterize fluid flow, pressure drop, and thermal transient behavior in complex flow geometries. However, with current CFD simulation techniques, the accurate modeling of turbulence structures is often …
-
Development of a One-Equation Eddy Viscosity Turbulence Model for Application to Complex Turbulent Flows
… 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 …
-
Implementation of a non-linear eddy viscosity turbulence model into Hydra-TH for fuel related applications
… [kappa]-[epsilon]non-linear eddy viscosity model (NLEVM) has been implemented into Hydra-TH, a Computational Fluid Dynamics (CFD) software being developed to support the nuclear reactor thermal-hydraulics modeling and simulation needs of the CASL program. This model adopts a non-linear …
-
Adjoint-based optimization of U-bend channel flow using a multi-fidelity eddy viscosity turbulence model
… wall-resolved Large Eddy Simulation (LES) models. The LES solution is shown to match experimental results, whereas the RANS solution is not sufficiently accurate. A process for training a RANS eddy viscosity field using the LES solution is provided. This approach is based on solving an …
-
Analysis of the wake behind a propeller using the finite element method with a two-equation turbulence model
… time-averaged Navier-Stokes equations and two turbulence transport equations for the turbulent kinetic energy and its rate of dissipation was solved by L/U decomposition and successive substitution with relaxation. An existing finite element code was modified with a low Reynolds number form for …
-
Uncertainty Analysis of Computational Fluid Dynamics Via Polynomial Chaos
… in performing uncertainty analysis of CFD models using conventional methods are associated with cost and effort. For these reasons, there is a need for the development and implementation of efficient stochastic CFD tools for performing uncertainty analysis. One of the main contributions of …
-
Applications of Lie Groups in Turbulence Modeling
… applied to the general two-dimensional k-epsilon turbulence model. Symmetry algebras for the k-epsilon turbulence model have been calculated by Khor'kova. and Verbovetsky. This systematic approach is applied to the specific flow problem of turbulent submerged free plane jets. Similarity solutions …
Page 1 of 12