|July 20, 2010, 11:56||
Error or Different Meaning of alpha in eEqu and hEqu of compressible solver?
Join Date: Nov 2009
Posts: 26Rep Power: 9
In compressible flow solvers, eEqu and hEqu share the same parameter "thermal diffusivity", or turbulence->alphaEff() in the following equations. However, my understanding of the meaning of thermal diffusivity should be different in these equaitons, i.e. , (for a laminar flow),
In eEqu, alpha = K / (Cv rho), where Cv, k and rho are heat capacity at constant volume, theremal conductivity and density, respectively.
while, in hEqu, alpha = k / ( Cp rho), where Cp, k and rho are heat capacity at constant pressure, theremal conductivity and density, respectively.
My questions are:
1, my understanding about alpha is right or wrong?
2, if i am right, is openFoam wrong ?, or there is specific application inside openfoam dealing with this issue?
In sonicFoam eEqu is
+ fvm::div(phi, e)
- fvm::laplacian(turbulence->alphaEff(), e)
In rhoPisoFoam hEqu is
+ fvm::div(phi, h)
- fvm::laplacian(turbulence->alphaEff(), h)
Last edited by universez; July 26, 2010 at 13:38.
|August 8, 2010, 11:51||
compare with rhoFurbFoam
you are not wrong in understanding but you have compare similar solvers like rhoTurbFoam in 1.5 and sonicFoam in 1.6.
iam working on both the slovers and i feel both are same (Unsteady Turbulent compressible solvers).
try to analyze with rhoTurbFoam that will clear your doubt.