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Old   September 29, 2006, 07:17
Default Pressure Gradient Parameter
  #1
Adam
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Has anyone had experience with calculating the pressure gradient paremeter and using this during the solver run?

The transition model uses this for its calculations, but i can't find any reference to that variable in the manuals, and it requres the calculation of the momentum thickness at every streamwise point in the flow, which will prove to be hard to do i think.

Regards

Adam
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Old   October 1, 2006, 20:30
Default Re: Pressure Gradient Parameter
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TB
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hmmm.... I'll try to help. If you're looking for pressure gradient parameter for the boundary layer flow, the formula should be: (theta/U)*(dU/ds) where dU/ds is local free stream velocity gradient and theta is the momentum thickness.

However, I didn't calculate this during solver run, only at the end of simulation. Are you working on Transient or steady state simulation?

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Old   October 2, 2006, 04:03
Default Re: Pressure Gradient Parameter
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Adam
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I'm running both steady state and transient.

Its the automatic calculation of the momentum thickness that is causing me some problems. I know that CFX must do it for their transition model, but am not sure if I can get access to that part of the code.

Adam
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Old   October 2, 2006, 06:23
Default Re: Pressure Gradient Parameter
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TB
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As I'm aware, calculation of momentum thickness always involves some integration of velocity profile. The quickest way is to contact your support for solutions.
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Old   October 3, 2006, 08:50
Default Re: Pressure Gradient Parameter
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Kiddo
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Hello, try to use UserFortran, there's a default subroutine: for ex.

CALL USER_GETVAR('Water at RTP.Pressure.Gradient',CRESLT, pPGRADIENT,CZ,DZ,IZ,LZ,RZ)
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Old   October 4, 2006, 04:27
Default Re: Pressure Gradient Parameter
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TB
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Hi... I think that's not the idea of a pressure gradient parameter.
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