CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   CFX (http://www.cfd-online.com/Forums/cfx/)
-   -   the initial condition for transient simulation (http://www.cfd-online.com/Forums/cfx/106205-initial-condition-transient-simulation.html)

junc August 21, 2012 22:33

the initial condition for transient simulation
 
hi, everyone.
i am modeling a ducted fan in cfx. And i'd like to run a transient analysis using the steady state simulation as an initial guess. however, it's very hard to reach convergence in the steady state simulation, and the RMS Residual Level of velocity is about 2.2*10^-4.
Can i use this steady condition as the initial guess for the transient simulation?
thanks, any help would be appreciated!

pavitran August 21, 2012 22:57

Hi
 
Check for the mass and momentum imbalances, if they are ok then you can use the result as initial conditon for transient simulation. You can have an additional check by monitoring some integral quantity like torque.

If the problem which your simulating is inherently transient in nature, then the residuals would be oscillating and achieving convergence criteria would be difficult.

All the best:)

junc August 22, 2012 06:13

thank you for your reply, i will check that.


All times are GMT -4. The time now is 23:49.