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Turbulent Boundary condition, viscosity ratio and length scale

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Old   February 16, 2013, 13:06
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Francisco
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Hi, I've made a larger domain and a finer mesh and run the 2D case again but this time full-scale.
I've used k-ep RNG instead of realizable.

Simulation starts well, no need to modify under-relazation factors, but it end up in divergence (picture 1) due to turbulence viscosity ratio (TVR) limited to 1e5 in too many cells.
I've taken a picture of TVR distribution just before divergence (picture 2) so I guess the problem is TVR limitation is reached in that area and then it's transported into the wake. I guess I need an finer mesh in the wake region to solve that, don't I?

I've checked y+ around the plate and it's always under 3 (picture 3).

Static pressure and x-wise velocity are plotted in pictures 4 and 5, they both seem right to me, including the profile distribution for the velocity.

Then I've tried a finer wake mesh but there must be something else wrong because divergence occurs just from the very begining.

Thanks
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3d 2d, flat plate, turbulence models, viscosity limitation

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