CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   FLUENT (http://www.cfd-online.com/Forums/fluent/)
-   -   Pressure Boundary Conditions (http://www.cfd-online.com/Forums/fluent/47598-pressure-boundary-conditions.html)

Dave March 13, 2008 06:09

Pressure Boundary Conditions
 
Dear All,

I have searched the forums already and didn't find the solution to the problem I am having. I have a simple case of a 2D channel 45mm long 9mm wide with a pressure-inlet at one end and pressure-outlet at the other. With a pressure difference of 1000Pa between inlet and outlet, the theoretical mass flow is 27kg/s. However, setting Total guage pressure at inlet to 1000Pa and total pressure at outlet to 0Pa Fluent predicts a mass flow of ~10kg/s. I understand Fluent's total pressure is a combination of hydrostatic and dynamic pressure. No gravity is involved in this simulation - it is just a pure laminar test case to validate another model but Fluent seems unable to solve.

Thank-you in advance for any suggestions,

Dave

Sellyg March 13, 2008 23:15

Re: Pressure Boundary Conditions
 
You can do the follwing: 1) use velocity bc instead pressure inlet; 2) after processing, you can read the pressure value at inlet.


ravi1650 June 8, 2009 17:05

Hi,

Even I am getting the same problem when I use pressure conditions at the boundary and the problem seems to be resolved when I use velocity inlet at the inlet boundary condition.. Bt I am unable to explain the reason for difference in results with these two different boundary conditions?
Please help.


All times are GMT -4. The time now is 10:01.