CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   CFX (http://www.cfd-online.com/Forums/cfx/)
-   -   about "Presure" in CFX results (http://www.cfd-online.com/Forums/cfx/22821-about-presure-cfx-results.html)

erick July 9, 2006 22:06

about "Presure" in CFX results
 
Dear Friends,

I am in trouble, could you help me?

In CFX Results, a varible "Presure" is calculated. How I can get the static pressure at a point?

I was confused by the following sentences from CFX help file: "When the - turbulence model is used, the fluctuating velocity components give rise to an additional pressure term to give the Modified Pressure where is the turbulent kinetic energy. In this case ANSYS CFX solves for the Modified Pressure. This variable is named "Pressure" in ANSYS CFX."

Please help me, thank you very much

Eric.

Joe July 10, 2006 07:04

Re: about "Presure" in CFX results
 
CFX Pressure = static pressure except for k-e based turbulence models, where CFX pressure = static pressure + normal turbulent fluctions (uu, vv, ww).

At least thats how I recall it...

Eric July 10, 2006 07:18

Re: about "Presure" in CFX results
 
Dear Mr. Joe,

Thank you for your help. Could you explain "normal turbulent fluctions (uu, vv, ww)." in details? Many thanks.

Best Regards Eric

HekLer July 11, 2006 11:25

Re: about "Presure" in CFX results
 
The turbulence fluctuations arise when the Navier Stokes equatinos are Reynolds averaged. This process results in the Reynolds Stress term. This term comes out in the wash and is a symmetric tensor. The diagonal components are the turbulent normal stress.

The turbulent normal stress is assumed to be included in the "solved for" pressure.



All times are GMT -4. The time now is 18:14.