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-   -   folded mesh in FSI (http://www.cfd-online.com/Forums/cfx/24029-folded-mesh-fsi.html)

steve May 23, 2007 17:51

folded mesh in FSI
 
I am simulating a static FSI problem over a fixed wing in transonic flow regime. The problem which arises is related to the remeshing of the boundary-layer mesh, which in my case is quite fine (low y+). I have tested various values of mesh stiffness and model exponent, via the three available methods in CFX, without any result. I am wondering any CEL expression related to the total mesh displacement would help?Did anyone test anything with success ? Thanks in Advance

johnny May 23, 2007 21:03

Re: folded mesh in FSI
 
Did you try reducing the exponent for the Increase Stiffness Near Walls setting? There is an upper limit for the stiffness, and sometimes using a large exponent forces the stiffness everywhere to hit this limit, resulting in a relative stiffness of unity. You can plot the mesh stiffness in Post to check.

steve May 24, 2007 07:33

Re: folded mesh in FSI
 
I tried to reduce the exponent to a value of 1 (minimum, while the default is 10, but no progress has been made!

Now i test a cel expression for the mesh stiffness value directly, which i enforce locally (large displacements) to increase the stifness.This expression in brief is:

1e+25*total mesh disp x*total mesh dip z +1e+9

Do you agree? (x and z are the main deformation directions) Have you ever used any cel for the stiffness with success? Thanks


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