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-   -   Convergence problem with target mass flow rate (http://www.cfd-online.com/Forums/fluent/98523-convergence-problem-target-mass-flow-rate.html)

ADL March 13, 2012 06:12

Convergence problem with target mass flow rate
 
Hi all,

I'm running an unsetady simulation of an uncompressible flow in a pipe with three outlets.
I've imposed a velocity profile at the inlet using a UDF (peak Re around 4000). I also have imposed the target mass flow rates at two of the outlets using a UDF and pressure outlet boundary condition, the mass flow rate is defined by an equation where the current time is a variable. The third outlet has a pressure outlet BC but no target mass flow rate specified. I haven't changed the gauge pressure as my flow is not supersonic.
However the simulation doesn't converge at second order and fluent ignores my instruction about the mass flow rate. The mass flow rate at the outlet for each time step is not the one I'm imposing with the function. Can anyone help me with this?
Thanks a lot

Zigainer March 20, 2012 15:05

I also had problems with target mass flow rate ....... I just deactivated the target mass flow rate and adapted the pressure so that I get the mass flow I want, but my simulation is steady state, so thatís maybe not working for you.

Anyone else??

Tech Neo May 29, 2012 21:11

Same problem
 
Hi, I am facing the same problem. Were you able to solve your problem ADL? Kindly let me know, if you have. Thank you


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