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Old   July 11, 2011, 07:20
Default multi-turbulence model
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hi,

I'm simulating rotating machinery problem.
inlet is mass-flow & temperature.
outlet is static pressure.
after solving (SST - is my turbulence) predicted inlet pressure is 32% more than test data.
what's is the problem?


for this i plan to choose some other turbulence model for stationary (ex. volute..) domains and SST for rotating domain only.
Is that good idea first?


pl somebody help me.
thank you
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Old   July 11, 2011, 19:08
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http://www.cfd-online.com/Wiki/Ansys..._inaccurate.3F
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Old   July 13, 2011, 12:17
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Hi,
First, you have to verify your machine dimensions especially the inlet and outlet areas then do a mesh sensitivity study, finaly try to obtain an Ypls less than 2 near the walls if you are using SST model.
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Old   July 14, 2011, 06:36
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hi ali,
what is " check machine dimensions especially the inlet and outlet areas"
Pl explain.
thank you
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Old   July 14, 2011, 07:52
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He means check that your geometry matches the experiment. Other than that all his comments (and much more detail) are mentioned on the FAQ link I referenced.
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Old   July 14, 2011, 07:56
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ok.
I have not done any changes in CAD model. it's same as test model.
and now i'm trying to find out my discretization error.
thank for your info.
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