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 Stokes February 10, 2006 14:46

About BC for turbulence k-omega models.

Hello, all, I'm testing the in-house k-omega/k-eps models by unstructured FEM method. I meet the negative k and convergence problems. It's well known that omega=(2~60)*dynamic visscous/(beta * y^2) depending on standard or SST or any other k-omega models etc, here, beta=0.075, y is the first grid point way the wall. For my testing case, visc is 10^-7 around, y 0.001, then the BC for omega is 10~250. However, if i impose 250.0 for example, then k is always negative. On the otherhand, if i impose 10.0, then there is no convergence of k/omega equaitons. Does anyone here have any comments about above problems? Thanks for your helps.

 micro11sl May 7, 2013 16:42

Quote:
 Originally Posted by Stokes ;40470 Hello, all, I'm testing the in-house k-omega/k-eps models by unstructured FEM method. I meet the negative k and convergence problems. It's well known that omega=(2~60)*dynamic visscous/(beta * y^2) depending on standard or SST or any other k-omega models etc, here, beta=0.075, y is the first grid point way the wall. For my testing case, visc is 10^-7 around, y 0.001, then the BC for omega is 10~250. However, if i impose 250.0 for example, then k is always negative. On the otherhand, if i impose 10.0, then there is no convergence of k/omega equaitons. Does anyone here have any comments about above problems? Thanks for your helps.
Did you get your problem sorted?

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