Solving boundary layer with k-e model
Hello
In fluent, you can use "Enhanced wall treatment" to solve the boudary layer with the k-e turbulence model. How can you do that with OpenFoam? Which boundary conditions to set instead of wall functions? Thank you |
Hi,
as far as I am understanding your question, you want to resolve the laminar sublayer with a fine mesh (with y-plus around 1) using the implemented k-epsilon turbulence model? In literature it is often pointed out, that if the laminar sublayer should be resolved with the k-epsilon model, additional damping functions (to limit the k production) are needed. In OF 1.6 one modified k-epsilon turbulence model for this usage is included. The Launder-Sharma low-Re k-epsilon model. http://www.cfd-online.com/Wiki/Low-Re_k-epsilon_models If you can manage provide small y-plus values to resolve the laminar sublayer, you can perhaps try this model. (Personally I have no experience with this model) Regards |
You totally understand and this is the model I was using but it gives me different results than fluent so I wanted to know if it was possible to stick as cloes as possible to the parameters in fluent by using the standard k-e model :)
Thanks for the answer! |
Quote:
Now the question is how did you set the boundary conditions at the walls? If you use a low-Re model, you should not use the wall-functions but directly specify the conditions for k and epsilon. Best, |
At the walls, k and epsilon are set to something like 1e-06 and nut is set as calculated
|
Hello Jérémy,
Did you manage to get what you wanted? I also want to resolve the BL with y+ around1, (simpleFoam) |
Hi All,
I am using MRFSimpleFoam, y+ value = 3, Growth factor = 1.2, layers = 15 and the whole domain has 6.3 Millions cells. I am using kOmegaSST, the problem is, simulation not all getting converged. my question is for kOmegaSST turb-model, is it right setting??? if not what should I change? I have given the boundary conditions as follows 0/nut, for all walls top0 { type nutkWallFunction; value uniform 0; } top1 { type nutkWallFunction; value uniform 0; } top2 { type nutkWallFunction; value uniform 0; } 0/k top0 { type kqRWallFunction; value uniform 0.062424; } top1 { type kqRWallFunction; value uniform 0.062424; } top2 { type kqRWallFunction; value uniform 0.062424; } 0/omega top0 { type omegaWallFunction; value uniform 0.99; } top1 { type omegaWallFunction; value uniform 0.99; } top2 { type omegaWallFunction; value uniform 0.99; } 0/U --> massFlowRate ---> 4m3/s inlet 0/p --> Gauge Pressure --> 0 Outlet Thanks, Aadhavan |
All times are GMT -4. The time now is 12:36. |