Launder Shrma Low Reynolds turbulence model case setup
Hi,
I am running a simulation with low Re turbulence model, I have checked the mesh, it is fine, there is no problem in it. I came up with successful case setup for kOmegaSST. It is working fine, but the results are deviating. So now I want to do the simulation with LaunderSharmaKE model, for that I am trying many different settings but none of them is working. I know that we no need to give any wall function for lowRe model, so I have given fixedValues for that. The BC's are as follows for SimpleFoam, Please have a look and help me. 0/k: internalField uniform 0.39; boundaryField { inlet { type fixedValue; value uniform 0.39; } outlet { type zeroGradient; } top0 // wall { type fixedValue; value uniform 1e-12; } 0/epsilon: inlet { type fixedValue; value uniform 0.26295; } outlet { type zeroGradient; } top0 // wall { type fixedValue; value uniform 1e-10; } 0/nut: internalField uniform 0; boundaryField { inlet { type calculated; value uniform 0; } outlet { type calculated; value uniform 0; } top0 // wall { type nutLowReWallFunction; value uniform 0; } 0/p: internalField uniform 0; boundaryField { inlet { type zeroGradient; } outlet { type fixedValue; value uniform 0; } top0 // wall { type zeroGradient; } 0/U: internalField uniform (0 0 0); boundaryField { outlet { type zeroGradient; } inlet { type flowRateInletVelocity; flowRate 2; // Volumetric/mass flow rate [m3/s or kg/s] value uniform (0 0 0); // placeholder } top0 //wall { type fixedValue; value uniform (0 0 0); } Thanks, Sivakumar |
Hi there,
Still I am not winning, some one please help me. I have done small change according to OpenFOAM training manual. for Wall, nut ----> fixedValue 0 k ------> fixedValue 0 (1e-12) epsilon ->zeroGradient but I have given small fixedValue (1e-10) k is always bounding for the above setting. I dont understand what is the problem, please help me. Thanks, Sivakumar |
I set up a case for buoyantBousinesqPimpleFoam and your turbulent model using HelyxOS. Setup a test case with a simple geometry and try using the BC's they setup. For me it worked at that time.
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Hi there,
I am happy to give you this information, the case setup for low Re model is successful. my problem was Y+ value, it was 1 or less, according the available information it is correct, but it is not at all working with Y+ of 1 or less. So I changed the Y+ value 3 -5, it is working fine. I hope I will get the good result. Regarding the wall function, low Re model wall function no need and high Re model yes wall function need. Low Re model: turbulence model : LaunderSharmaKE nut ----> fixedValue (0) k -----> fixedValue (1e-12) epsilon -----> fixedValue (1e-8) it can be zeroGradient as well nuTilda -----> fixedValue (0) for high Re model: nut ----> nutkWallFunction value (0) k -------> kqRWallFunction value uniform (*******) epsilon ----> epsilonWallFunction value uniform (*******) nuTilda -----> zeroGradient I hope it will be useful. Thanks, Sivakumar |
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