Problem with pointDisplacement in 3D

alexvaleije · May 3, 2016, 14:12

Hi everyone,

I am working with a 3D simulation of the flow around a prism which moves "freely" inside a channel. "Freely" means that the prism can go up and down, but also can rotate around the Z axis (assume that the flow goes in the X direction). I am doing this with the sixDoFRigidBodyDisplacement library and a mod of pimpleDyMFoam in OF 2.2.1.

The thing is that i get some good results when I run this in 2D, but in the moment I go into 3D, the mesh twists in a way that it collapses into itself. I think that this can be related to the boundary condition I apply on the moving patches, which in 2D have the "empty" BC.

Have someone experienced something similar to that or could help me with this?

Regards

Alex

Zoe Yamaguchi · September 25, 2018, 12:13

Any luck with the solution? I resorted to moving the whole mesh while keeping the prism fixed, instead.

alexvaleije · September 25, 2018, 12:25

Unfortunately, no. I was trying with the 6DoF libraries attached in the new versions, but with my particular cases I haven't got any good results.

However, i think that my case may have some particularities that may lead to the failure, because I've tried with other cases with positive results, so I'm not sure of what could it be the cause.

Hope you have more luck than me. Regards,

Alex

May 3, 2016, 14:12	Problem with pointDisplacement in 3D	#1
alexvaleije Member Alejandro Valeije Join Date: Nov 2014 Location: Spain Posts: 52 Rep Power: 11	Hi everyone, I am working with a 3D simulation of the flow around a prism which moves "freely" inside a channel. "Freely" means that the prism can go up and down, but also can rotate around the Z axis (assume that the flow goes in the X direction). I am doing this with the sixDoFRigidBodyDisplacement library and a mod of pimpleDyMFoam in OF 2.2.1. The thing is that i get some good results when I run this in 2D, but in the moment I go into 3D, the mesh twists in a way that it collapses into itself. I think that this can be related to the boundary condition I apply on the moving patches, which in 2D have the "empty" BC. Have someone experienced something similar to that or could help me with this? Regards Alex

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September 25, 2018, 12:13		#2
Zoe Yamaguchi New Member Join Date: Apr 2015 Posts: 2 Rep Power: 0	Any luck with the solution? I resorted to moving the whole mesh while keeping the prism fixed, instead.

September 25, 2018, 12:25		#3
alexvaleije Member Alejandro Valeije Join Date: Nov 2014 Location: Spain Posts: 52 Rep Power: 11	Unfortunately, no. I was trying with the 6DoF libraries attached in the new versions, but with my particular cases I haven't got any good results. However, i think that my case may have some particularities that may lead to the failure, because I've tried with other cases with positive results, so I'm not sure of what could it be the cause. Hope you have more luck than me. Regards, Alex