CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   CFX (http://www.cfd-online.com/Forums/cfx/)
-   -   Transient Flow, Transient Pressure in Work Bench (http://www.cfd-online.com/Forums/cfx/23936-transient-flow-transient-pressure-work-bench.html)

Erich May 4, 2007 10:11

Transient Flow, Transient Pressure in Work Bench
 
Hello,

We are modeling a rotating fan that undergoes relatively large changes in pressure as it rotates. In order to get the mapping to work in the same global coordinate system in Workbench, I rotate the stationary components in Pre and set up definition files for multiple time steps/angle of rotations. When each pressure is applied at successive time steps, the Resultant loads map at 100% and appear correct. The only problem is that the stress levels gradually increase to a much higher value than predicted in the static analysis. The overall magnitude of the pressures individually would not yield such a high stress. It is as if the pressures are additive, as opposed to only applied at those time steps. Is there a CMD file in Workbench that would ensure the CFX pressures are only applied at their own individual time steps? Could there be something else?

Thanks for your help,

Erich

Erich May 8, 2007 11:55

Re: Transient Flow, Transient Pressure in Work Ben
 
Update:

Our Ansys Support office gave us a work around. There are Ansys commands available to turn on and off the pressure loads at their respective time steps. Otherwise, the pressures are seen as additive...

Thanks Ansys Support!

Erich


All times are GMT -4. The time now is 00:34.