Flow rate convergence

[jkmalagi]

Dear all,

I have run a steady state fluid flow analysis - the system has an air volume with one prescribed inlet/outlet & one external intake fan. The fan delivers .0014 m^3/sec flow into the system.

However, once the analysis is done & I add up the flow rate of all the nodes on the fan surface, I see that the flow is .00014 in^3/sec. I have tried different solvers, slightly denser mesh size & changing convergence parameters without success. All of these changes still show a similar result (.00014in^3/sec instead of .0014in^3).

What might be causing this behavior? I  have set "continue to next step" if the solution encounters oscillation so convergence may be a suspect. The archive file is too big to attach so I am sending analysis summary file.

I appreciate any feedback you can give me.

Jay

[AstroJohnPE · Accepted solution]

If you are really summing the flow rate at the nodes, that would be one problem. You need to select the faces of the elements, not the nodes. Hopefully that will get you closer to the target flow rate.

[jkmalagi]

Hello John

Thank you! That worked, I switched off smoothing options & selected faces instead of nodes & summed the flow rate values. The result are correct.

Best regards

Jay