Theses and Dissertations

Issuing Body

Mississippi State University

Advisor

Sreenivas, Kidambi

Committee Member

Whitfield, David L.

Committee Member

Taylor, Lafayette

Date of Degree

12-14-2001

Original embargo terms

MSU Only Indefinitely

Document Type

Graduate Thesis - Campus Access Only

Major

Computational Engineering

Degree Name

Master of Science

College

College of Engineering

Department

Computational Engineering Program

Abstract

This report presents the study of two-equation turbulence modeling. The primary objective of this study is to implement two-equation k-ε and k-ω turbulence models as a part of the incompressible flow solver, U²NCLE, on unstructured grids. There are several two-equation models but the selection of one which is in par with the model in UNCLE solver is required so that this model can be compared for robustness and accuracy as dem-onstrated by turbulence models in UNCLE. The selection also requires that the pre-defined arrays and variables can be used to avoid overhead and deviation from the solution procedure used in U²NCLE. The present study deals with the two-equation k-ε model contributed by Shih and Lumley and the two-equation k-ω model contributed by Wilcox. Implementation of these models will give the user multiple options of two-equation turbulence modeling for solution purpose. Particular attention is paid to the efficiency of the implementation. Various approximations to the source terms are considered and the most optimal and accurate approximation is identified. These models are validated via relatively small model problems, for example a flat plate case, by comparing the results with the results obtained from the respective models in UNCLE and the existing two-equation q-ω model in U²NCLE. Further validation is carried out by comparing computed forces and moments with experi-mental data for the SUBOFF model with sail and stern appendages.

URI

https://hdl.handle.net/11668/18942

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