CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   CFX (http://www.cfd-online.com/Forums/cfx/)
-   -   multi-turbulence model (http://www.cfd-online.com/Forums/cfx/90463-multi-turbulence-model.html)

turbotel July 11, 2011 07:20

multi-turbulence model
 
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

ghorrocks July 11, 2011 19:08

http://www.cfd-online.com/Wiki/Ansys..._inaccurate.3F

Abou ali July 13, 2011 12:17

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.

turbotel July 14, 2011 06:36

hi ali,
what is " check machine dimensions especially the inlet and outlet areas"
Pl explain.
thank you

ghorrocks July 14, 2011 07:52

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.

turbotel July 14, 2011 07:56

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.


All times are GMT -4. The time now is 06:00.