moving mesh rolling piston

JohannVV · November 5, 2010, 13:04

hi all.
i'm simulating a rolling piston with a moving mesh.
I use the remesh method . the setings for the walls of the slider which is directly connected to the piston are; deforming.
the piston motion is defined by a udf.

the main problem is that the simulation takes some iterations, but then accurs an arror.
the error at the calculation process is: Divergence detected at AMG-Solver
and the error at the preview mesh motion is: negative cell volumen detected.

do some one has a hint, what is wrong

arash_7444 · November 6, 2010, 16:51

Hi,

I think It's because of poor quality of your meshes. try to improve it, it might help

JohannVV · November 7, 2010, 18:31

Hi arash_7444 thank you for reply.
I dont think that the problem is because of poor mesh quality, but in any case I will check it tomorrow.
what i not understand is: why the calculation of the case takes some iterations an then the error eccurs. schould the mesh not be remeshed if the maximum scew gous over the maximum scew factor?

JohannVV · November 8, 2010, 03:21

hi arash_7444, I just checked the mesh quality and the error is the same .
may you have any other hints, how to solve this problem. thank's in andvance.

JohannVV · November 11, 2010, 10:46

i solved the problem. the slider and the rotary pistow were connected, but this is not allowed if the piston is a rigid body.

November 5, 2010, 13:04	moving mesh rolling piston	#1
JohannVV New Member Join Date: Sep 2010 Location: germany Posts: 20 Rep Power: 16	hi all. i'm simulating a rolling piston with a moving mesh. I use the remesh method . the setings for the walls of the slider which is directly connected to the piston are; deforming. the piston motion is defined by a udf. the main problem is that the simulation takes some iterations, but then accurs an arror. the error at the calculation process is: Divergence detected at AMG-Solver and the error at the preview mesh motion is: negative cell volumen detected. do some one has a hint, what is wrong

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November 6, 2010, 16:51		#2
arash_7444 Member Arash Join Date: Dec 2009 Location: Denmark Posts: 37 Rep Power: 17	Hi, I think It's because of poor quality of your meshes. try to improve it, it might help

November 7, 2010, 18:31		#3
JohannVV New Member Join Date: Sep 2010 Location: germany Posts: 20 Rep Power: 16	Hi arash_7444 thank you for reply. I dont think that the problem is because of poor mesh quality, but in any case I will check it tomorrow. what i not understand is: why the calculation of the case takes some iterations an then the error eccurs. schould the mesh not be remeshed if the maximum scew gous over the maximum scew factor?

November 8, 2010, 03:21		#4
JohannVV New Member Join Date: Sep 2010 Location: germany Posts: 20 Rep Power: 16	hi arash_7444, I just checked the mesh quality and the error is the same . may you have any other hints, how to solve this problem. thank's in andvance.

November 11, 2010, 10:46		#5
JohannVV New Member Join Date: Sep 2010 Location: germany Posts: 20 Rep Power: 16	i solved the problem. the slider and the rotary pistow were connected, but this is not allowed if the piston is a rigid body.