Increasing residuals!!

Martin1 · May 12, 2015, 18:53

Hi,

I simulated a turbulence flow of an elliptical pipe which converged and I got reasonable results. Then I did the same simulation but this time I changed the orientation of the major and minor axis. Now my residuals are positively increasing and the flow is dissapering. I don't now why it does like this. Does anyone have an idea?

Also after some iterations, the mesh of the inlet disappears as well

villager · May 12, 2015, 20:10

Hi!
And how did you change your axes? Did you construct the mesh from the beginning by hand - maybe, some mesh issues.
Do you use external forces (gravitation)?
Have you started your calculation from previous results (exchanging the mesh) or created the case file from scratch?

Martin1 · May 12, 2015, 20:13

Quote:

Originally Posted by villager

Hi!
And how did you change your axes? Did you construct the mesh from the beginning by hand - maybe, some mesh issues.
Do you use external forces (gravitation)?
Have you started your calculation from previous results (exchanging the mesh) or created the case file from scratch?

I changed the axes by the rotate mesh option. So the axis is in the same direction as before. No gravity. No I did not do any changes to the mesh, that is the same. No case files or anything similar either.

Martin1 · May 12, 2015, 21:11

Oh sorry, I misunderstood your question. I changed the axis in the design modeler, I just changed the diameters. Did not construct the mesh or geometry again.

May 12, 2015, 18:53	Increasing residuals!!	#1
Martin1 Member Martin Join Date: May 2015 Posts: 30 Rep Power: 10	Hi, I simulated a turbulence flow of an elliptical pipe which converged and I got reasonable results. Then I did the same simulation but this time I changed the orientation of the major and minor axis. Now my residuals are positively increasing and the flow is dissapering. I don't now why it does like this. Does anyone have an idea? Also after some iterations, the mesh of the inlet disappears as well Last edited by Martin1; May 12, 2015 at 19:41. Reason: additional information

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May 12, 2015, 20:10		#2
villager Member vlg Join Date: Jul 2011 Location: My home :) Posts: 81 Rep Power: 17	Hi! And how did you change your axes? Did you construct the mesh from the beginning by hand - maybe, some mesh issues. Do you use external forces (gravitation)? Have you started your calculation from previous results (exchanging the mesh) or created the case file from scratch?

May 12, 2015, 21:11		#4
Martin1 Member Martin Join Date: May 2015 Posts: 30 Rep Power: 10	Oh sorry, I misunderstood your question. I changed the axis in the design modeler, I just changed the diameters. Did not construct the mesh or geometry again.