Mesh Displacement Residual

lingdeer · November 17, 2011, 17:05

I am running 2way FSI coupling ANSYS and CFX.
Both for fluid and solid solver I saw them converging well.
However, the residual of the mesh displacement remains high: 10e-1
I tried to increase the no. of max coeff loop in equation class setting under solver control from 10 to 30, because I am thinking may there isnt sufficient loops for it to converge.
However I don't know how to monitor it, to see if this is improving by allowing it to run more no. of loops. Anyone has any idea?
Thanks!

stumpy · November 17, 2011, 17:23

The out file shows all the loops and the residuals for the mesh displacement equation. Are you using double precision? If not, turn that on. Note that as long as your mesh doesn't fold then these residuals do not change the accuracy of your solution. Higher residuals may cause the mesh to fold sooner if you are deforming it a long way though.

lingdeer · November 17, 2011, 17:54

I see. Thank you stumpy!

November 17, 2011, 17:05	Mesh Displacement Residual	#1
lingdeer Member Lingdeer Join Date: Jul 2011 Posts: 49 Rep Power: 14	I am running 2way FSI coupling ANSYS and CFX. Both for fluid and solid solver I saw them converging well. However, the residual of the mesh displacement remains high: 10e-1 I tried to increase the no. of max coeff loop in equation class setting under solver control from 10 to 30, because I am thinking may there isnt sufficient loops for it to converge. However I don't know how to monitor it, to see if this is improving by allowing it to run more no. of loops. Anyone has any idea? Thanks!

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November 17, 2011, 17:23		#2
stumpy Senior Member Join Date: Apr 2009 Posts: 531 Rep Power: 21	The out file shows all the loops and the residuals for the mesh displacement equation. Are you using double precision? If not, turn that on. Note that as long as your mesh doesn't fold then these residuals do not change the accuracy of your solution. Higher residuals may cause the mesh to fold sooner if you are deforming it a long way though.

November 17, 2011, 17:54		#3
lingdeer Member Lingdeer Join Date: Jul 2011 Posts: 49 Rep Power: 14	I see. Thank you stumpy!