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.

DOI

https://doi.org/10.31274/etd-180810-3972

Copyright Owner

Zifei Yin

Language

en

File Format

application/pdf

File Size

58 pages

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