Error in CFD online course Elbow duct.

Question

Im using Omnis 5.2 software, as i simulate the elbow challenge im facing the error

The simulation Simulation 1 has finished but the convergence criterion cannot be reached.
Check your simulation settings and residuals. and i tried many times changing the CFL number also still im facing the error and i couldn't complete the tast.

Manuel NIB · Accepted Answer

Hi Rishi, 
 please note: This is "just" a warning and not an error. The message means that simulation reached the number of iteration without meeting the specified convergence criterion (see the screen shot below where you can specifiy these settings). In our everyday CFD projects we have this quite often and in most of the cases (if carefully cheked) the results are very reliable. 
 
 Having said this, the case of challenge 2 should meet the convergence criterion. So it is very likely a setting in your setup differs from the values in the hand-out. So I would advise you to go through all the settings (once again). Please also check your mesh settings. Make in particular sure that the visous layers are only activated on the wall. Viscous layers should not be activated on inlet and outlet. 
 Best regards Manuel

Commodaro · Answer

Hi, 
 I've re-done the sim, and it converges with these parameters... when it failed to me, it might be that a value was wrongly entered due to the slowness I had on the connection to the computing machine. We will never know :-)

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Error in CFD online course Elbow duct.

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