Mesh deformation using user fortran

matled · February 17, 2010, 10:03

Hi all,

I'm performing a FSI simulation using CFX and a custom code for the structural part. It deals with membranes. At the moment I'm performing a CFX run, stopping it and exporting the pressures on a specified boundary. Then I import them on the custom code to compute the membrane deformations. At this point I create a new mesh and restart a CFX calculation. I need 7-8 iterations of this procedure to achieve a convergence.

I would like to use CFX 12 mesh deformation capabilities in order to avoid remeshing. I can provide the displacements of each node of the structural grid, and eventually interpolate the displacements to obtain the same nodes of the cfx grid (but I would prefer this to be done by CFX). I think that user fortran is needed to set the displacements of each node of the mesh. Is there any example available that can help me writing the routines? I need to load the displacements from a file (I can decide the format since i have full control on the output of the custom code) and set the mesh motion.

Thanks in advance

ghorrocks · February 17, 2010, 16:56

There are a few examples which get provided in the CFX tutorials for this.

FSI is already in CFX and ANSYS Mechanical and is a pretty good coupling from all reports (I have never used it). Why do you need a custom code?

matled · February 18, 2010, 03:25

Thanks Glenn,

I've looked at the tutorials but the mesh deformation is made using CEL functions (valve) or with a coupling with ANSYS (Oscillating plate). I'll check the documentation in depth. I need the custom code for the structural part because there's a lot of work on it, I'm confident of its results for our specific problem and I don't want to create a brand new model in ANSYS Mechanical (I don't even know if it's possible to do it, it's not my work, I 'm involved in the CFD part).

ghorrocks · February 18, 2010, 16:49

In CFX V11 the ball valve tutorial one used a fortran method. I think it was removed in V12. If you can get your hands on the documentation for V11 you will see the fortran they used.

February 17, 2010, 10:03	Mesh deformation using user fortran	#1
matled New Member Join Date: Jul 2009 Posts: 4 Rep Power: 16	Hi all, I'm performing a FSI simulation using CFX and a custom code for the structural part. It deals with membranes. At the moment I'm performing a CFX run, stopping it and exporting the pressures on a specified boundary. Then I import them on the custom code to compute the membrane deformations. At this point I create a new mesh and restart a CFX calculation. I need 7-8 iterations of this procedure to achieve a convergence. I would like to use CFX 12 mesh deformation capabilities in order to avoid remeshing. I can provide the displacements of each node of the structural grid, and eventually interpolate the displacements to obtain the same nodes of the cfx grid (but I would prefer this to be done by CFX). I think that user fortran is needed to set the displacements of each node of the mesh. Is there any example available that can help me writing the routines? I need to load the displacements from a file (I can decide the format since i have full control on the output of the custom code) and set the mesh motion. Thanks in advance

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February 17, 2010, 16:56		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,700 Rep Power: 143	There are a few examples which get provided in the CFX tutorials for this. FSI is already in CFX and ANSYS Mechanical and is a pretty good coupling from all reports (I have never used it). Why do you need a custom code?

February 18, 2010, 03:25		#3
matled New Member Join Date: Jul 2009 Posts: 4 Rep Power: 16	Thanks Glenn, I've looked at the tutorials but the mesh deformation is made using CEL functions (valve) or with a coupling with ANSYS (Oscillating plate). I'll check the documentation in depth. I need the custom code for the structural part because there's a lot of work on it, I'm confident of its results for our specific problem and I don't want to create a brand new model in ANSYS Mechanical (I don't even know if it's possible to do it, it's not my work, I 'm involved in the CFD part).

February 18, 2010, 16:49		#4
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,700 Rep Power: 143	In CFX V11 the ball valve tutorial one used a fortran method. I think it was removed in V12. If you can get your hands on the documentation for V11 you will see the fortran they used.