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Jens Goldberg October 17, 2008 03:31

Meshing
 
Hello! I have problem concerning the mesh quality of my simulation. It consists of a small hydraulic turbine (aperture:380mm, length 500mm) which is situated in a channel (3000mmx3000mmx6000mm) and is only driven by the kinetic energy of the water. To simulate this application I have two parts the hydraulic turbine and the channel. After some time I have managed to mesh both with high quality meshs keeping the edge length ratio under 100 and the element volume ratio under 20. However if I combine both meshes in CFX-Pre and start the simulation the values of the maximum mesh expansion factor and minimum orthogonality angle are never in the range of a good quality mesh. Does somebody know how I can manage to get the minimum orthogonality angle and the maximum mesh expansion factor to stay in the range of a good mesh? Thank you for your help.

Jens


Glenn Horrocks October 19, 2008 19:15

Re: Meshing
 
Hi,

Generating good quality meshes takes skill, practice and good software. Sounds like you should do a meshing training course.

Glenn Horrocks

Rogerio Fernandes Brito October 20, 2008 06:06

Re: Meshing
 
if u have circle boundaries, use an o-grid block to avoid bad angles and to increase the angle among the elements. Otherwise, you will have problems of convergence.

If u have a complex geometry, use tetra mesh.

Here, some tutorials to help you out.

http://www.4shared.com/dir/8279926/7..._ICEM_etc.html

Give a look on my hexa meshes examples:

http://www.4shared.com/dir/7741665/a...os_no_CFX.html



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