CFX Moving Mesh Contact "Management"

peppeone · January 7, 2011, 06:30

Hi All,
I don't know if anyone has experienced this problem, I hope someone can help me. I'm simulating an injector and its mobile element obviously moves up and down. Until now the only way to simulate its complete closure is to have some interpolation. I would like to ask you if it is possibile with Ansys CFX to simulate the complete closure with a moving mesh, i.e. CFX is capable of eliminating some elements in the contact region.
So far I haven't been able to find either tutorials or helps regarding this subject.
It should be a news of R 13.0.

Thanks

Matteo

singer1812 · January 7, 2011, 21:19

If the flow is incompressible you can do this with immersed solids.

peppeone · January 17, 2011, 09:33

Thanks, but for what concerns compressible flows?

ghorrocks · January 17, 2011, 17:51

I am not certain but I do not think the variable density is properly accounted for.

Other ways of closing a valve are:
1) Use a GGI interface and slide it shut. GGIs correctly handle an interface which can open or shut.
2) Use standard moving mesh to squash the pinch point down so much that the flow is basically stopped. Then remesh with a new mesh where the pinch point is shut and continue the simulation.

Both of these methods work fine with compressible flow, but sometimes they require subtle changes to the geometry or the assumption that the flow is insignifcant when you interpolate to the closed mesh.

January 7, 2011, 06:30	CFX Moving Mesh Contact "Management"	#1
peppeone New Member Join Date: Jan 2011 Posts: 2 Rep Power: 0	Hi All, I don't know if anyone has experienced this problem, I hope someone can help me. I'm simulating an injector and its mobile element obviously moves up and down. Until now the only way to simulate its complete closure is to have some interpolation. I would like to ask you if it is possibile with Ansys CFX to simulate the complete closure with a moving mesh, i.e. CFX is capable of eliminating some elements in the contact region. So far I haven't been able to find either tutorials or helps regarding this subject. It should be a news of R 13.0. Thanks Matteo

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January 7, 2011, 21:19		#2
singer1812 Senior Member Edmund Singer P.E. Join Date: Aug 2010 Location: Minneapolis, MN Posts: 511 Rep Power: 21	If the flow is incompressible you can do this with immersed solids.

January 17, 2011, 09:33		#3
peppeone New Member Join Date: Jan 2011 Posts: 2 Rep Power: 0	Thanks, but for what concerns compressible flows?

January 17, 2011, 17:51		#4
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,870 Rep Power: 144	I am not certain but I do not think the variable density is properly accounted for. Other ways of closing a valve are: 1) Use a GGI interface and slide it shut. GGIs correctly handle an interface which can open or shut. 2) Use standard moving mesh to squash the pinch point down so much that the flow is basically stopped. Then remesh with a new mesh where the pinch point is shut and continue the simulation. Both of these methods work fine with compressible flow, but sometimes they require subtle changes to the geometry or the assumption that the flow is insignifcant when you interpolate to the closed mesh.