|
[Sponsors] |
![]() |
![]() |
#1 |
Member
|
Hi all,
I'm working on a LowReynoldsNumber ReynoldsStressModel based on Wilcox's. I just have a couple of questions regarding existing compressible RSMs. 1) I guess that laminar behavior and modeling is not affected by turbulence models selections. I mean that a non-turbulent case could always be modeled as turbulent with mut=0. And results should not be influenced by the choice of turbulent model. So why divRhoR for RSM is returning: fvc::div( rho_ * R_,"divRhoR") - fvm::laplacian(muEff(), U) + fvc::laplacian(mut_, U) resulting for a laminar case in - fvm::laplacian(mu(), U) that is not consistent with the other two equation models: - fvm::laplacian(mu(), U) - fvc::div(mu()*dev2(fvc::grad(U)().T())) ? Might it be a bug? Possible fix: fvc::div( rho_ * R_,"divRhoR") - fvm::laplacian(muEff(), U) + fvc::laplacian(mut_, U) - fvc::div(mu()*dev2(fvc::grad(U)().T())) 2) Are there any specific solvers for RSM? 3) How do you manage (I'm still working with OF-1.3 and I saw inthe new version this problem is oslved) the possibility for R to result non-symmetric? 4) How do you model turbulent heat flux? divRhoUh does not seem to be implemented in neither Launder&Gibson nor LRR, so they still model isotropic turbulent heat flux. I would like to use Generalized Gradient Diffusion Hypothesis. So my divRhoUh results to be: - fvc::div(mut_* 3.3 *(R_ & tgradh())/k_,"divRhoUh") + fvc::laplacian(mut_* alphah, h) - fvm::laplacian(alphaEff(), h) I found constant 3.3 to be valid for flat plates (Ameri 2002). Is there anyone who have already done it and could suggest me other expressions? Thanks a lot for your time, Cosimo
__________________
Cosimo Bianchini Ergon Research s.r.l. Via Panciatichi, 92 50127 Florence - ITALY Tel: +39 055 0763716 Mob: +39 320 9460153 e-mail: cosimo.bianchini@ergonresearch.it URL: www.ergonresearch.it |
|
![]() |
![]() |
![]() |
|
|
![]() |
||||
Thread | Thread Starter | Forum | Replies | Last Post |
Reynolds Stress Models | amelia | OpenFOAM Running, Solving & CFD | 1 | August 11, 2005 17:12 |
reynolds stress | tufito | Main CFD Forum | 3 | March 10, 2005 15:40 |
Reynolds stress | Lee | FLUENT | 0 | September 24, 2002 06:50 |
Reynolds Stress Models | Roued | Main CFD Forum | 20 | February 8, 2000 02:58 |
Reynolds Stress Models | Roued | CFX | 2 | February 7, 2000 10:33 |