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how to define the symmetric boundary condition for Menter's SST turbulence model?

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Old   November 22, 2012, 04:05
Talking how to define the symmetric boundary condition for Menter's SST turbulence model?
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hello,

I am using Menter's SST turbulence model in the turbulent plate case described in http://turbmodels.larc.nasa.gov/flatplate.html.
How should I define the boundary condition at the symmetric part before the flat plane.

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Old   November 22, 2012, 05:38
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Use wall condition with zero shear.
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Old   November 22, 2012, 07:16
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thanks for your reply.
In process of solving the NS equations, it is OK that the no shear wall boundary condition can be applied.
But in turbulent models, the variables are 'k' and 'omega', how can I define the no shear wall boundary?
could you explain it more clearly?

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Old   November 22, 2012, 07:19
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which solver you are using?
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Old   November 22, 2012, 07:33
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you mean NS equations part? WENO5 for convective terms and 2nd center scheme for viscous terms.
And for turbulent models, 1st upwind scheme for convective terms and 2nd center scheme for diffusion terms.

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Old   November 22, 2012, 08:06
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Apply the wall boundary condition at the part of wall with zero shear (slip). Treat the plate as no slip boundary
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Old   November 22, 2012, 08:59
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yes, I did as you said in solving the NS. When solving the laminar plate, I got good results compared with the Blasius solution.

But when I turn on the turbulence model, the eddy viscosity(turbulent viscosity) is somewhat smaller than the results given in the nasa website. After checking every part of turbulence model, I found the symmetric boundary conditions before the plate for the turbulence model equations had very previous effects on the turbulent viscosity.

So I am wondering which boundary condition should I adopt?

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Old   November 23, 2012, 08:45
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A symmety boundary condition is applied by setting the wall-normal gradient of the variables to zero.
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Old   November 24, 2012, 02:53
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thank you. I am trying this way. hope it works.

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