Degree Type

Thesis

Date of Award

2015

Degree Name

Master of Science

Department

Aerospace Engineering

First Advisor

Paul A. Durbin

Abstract

The current work puts forth an implementation of a dynamic procedure to locally compute the value of the model constant CDES , as used in the eddy simulation branch of Delayed Detached Eddy Simulation (DDES). Former DDES formulations [P. R. Spalart et al., "A new version of detached-eddy simulation, resistant to ambiguous grid densities," Theor. Comput. Fluid Dyn. 20, 181 (2006); M. S. Gritskevich et al., "Development of DDES and IDDES formulations for the k omega shear stress transport model," Flow, Turbul. Combust. 88, 431 (2012)] are not conducive to the implementation of a dynamic procedure due to uncertainty

as to what form the eddy viscosity expression takes in the eddy simulation branch. However, a recent, alternate formulation [K. R. Reddy et al., "A DDES model with a Smagorinsky-type eddy viscosity formulation and log-layer mismatch correction," Int. J. Heat Fluid Flow 50, 103 (2014)] casts the eddy viscosity in a form that is similar to the Smagorinsky, LES (Large Eddy Simulation) sub-grid viscosity. The resemblance to the Smagorinsky model allows the implementation of a dynamic procedure similar to that of Lilly [D. K. Lilly, "A proposed modification of the Germano subgrid-scale closure method," Phys. Fluids A 4, 633 (1992)]. A limiting function is proposed which constrains the computed value of CDES , depending on the fineness of the grid and on the computed solution. In addition to the dynamic procedure, influence of inflow condition is also explored in this work.

Copyright Owner

Zifei Yin

Language

en

File Format

application/pdf

File Size

58 pages

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