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-   -   control variable bound in cfx (http://www.cfd-online.com/Forums/cfx/63566-control-variable-bound-cfx.html)

klarke April 13, 2009 06:46

control variable bound in cfx
 
HI,everyone
I am doing a compressor transient research,it have run a lot of time step,but suddenly,it stopped like below:(
Error in subroutine GET_SPECVAR :
Specified values for Total Temperature are out of bounds on Outlet GETVAR originally called by subroutine CAL_ENTHTOT). So did you have any experience of this error or how to control the varible bound.Thanks a lot!

joey2007 April 16, 2009 17:01

Take a intermediate result or backup and check the total temperature. Suppose the result is unphysical.

Daniel Frederik June 23, 2014 08:00

If the result is unphisical is there still a way to make it work or does that mean, that it is phisically impossible to simulate that case?

ghorrocks June 23, 2014 20:29

This could be caused by a numerical wander which will pass and it will eventually converge to the correct value, or it could be that the simulation was not physically possible in the first place.

I would save a results file just before the crash and see what it look like.

Daniel Frederik June 24, 2014 07:29

Thank you Glenn,
I solved the problem now by using a initial File of a previous run with other boundary condition values. For some reason the Total Temperature went out of bounds without an adequate initial guess.

ghorrocks June 24, 2014 20:15

This is quite common. That is why a good initial condition helps a lot.


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