Rahman-Siikonen-Agarwal Model
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0.05\;<\;A_\epsilon\;<\;0.11 \quad Commonly \;A_\epsilon = \tilde{C}_\mu | 0.05\;<\;A_\epsilon\;<\;0.11 \quad Commonly \;A_\epsilon = \tilde{C}_\mu | ||
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+ | ==References == | ||
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+ | * {{reference-paper|author=Spalart, P. R. and Allmaras, S. R.|year=1994|title=A One-Equation Turbulence Model for Aerodynamic Flows|rest=La Recherche Aerospatiale n 1, 5-21}} | ||
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+ | [[Category:Turbulence models]] |
Revision as of 22:03, 14 August 2012
Introduction
The Rahman-Agarwal-Siikonen (RAS) Turbulence model is a one-equation eddy viscosity model based on closure. The R-transport equation along with the Bradshaw and other empirical relations are used to solve for the turbulent viscosity. A damping function, , is used to represent the kinematic blocking by the wall. To avoid defining a wall distance, a Helmholtz-type elliptic relaxation equation is used for . The model has been validated against a few well-documented flow cases, yielding predictions in good agreement with DNS and experimental data.
RAS Model
The turbulent eddy viscosity is given by
The R-transport Equation:
Realizable Time Scale:
Coefficient :
Damping Function:
Other Model Coefficients:
and :
Constants:
References
- Spalart, P. R. and Allmaras, S. R. (1994), "A One-Equation Turbulence Model for Aerodynamic Flows", La Recherche Aerospatiale n 1, 5-21.