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Ankur Srivastava October 29, 2008 15:53

Flow past a ship model
 
I have to model flow past a 3D ship model kept in a wind tunnel. I have modeled the wind tunnel as a big rectangular block with the ship model at its center-line. Now when I do the volume mesh, I can only see the meshing on the surface of the ship and the surface of the block. The fluid in between the ship and the wind tunnel does not get meshed by just clicking the volume mesh button.

I need to finely mesh the fluid downstream of the ship to capture vortex formation. How should I do this? I created the model in STAR design and used STAR CCM to do the rest.

I would appreciate any help.

Thanks


tom October 30, 2008 12:24

Re: Flow past a ship model
 
Just a guess. Maybe it is all meshed but your are not applying the volume mesh representation in your scene. Run a diagnostics to see if it is meshed

Ankur Srivastava October 30, 2008 12:48

Re: Flow past a ship model
 
Tom,

Thanks for replying. When I view the mesh I do it by opening a new mesh scene. Additionally, during post processing when I open a velocity vector field and select all parts I see the vectors only at the ship model surface and at the inlet and outlet faces. I do not see vectors in the region between the ship and the wind tunnel faces. I think I am doing something fundamentally wrong because the software does not recognize there is a volume between the ship and wind tunnel model.

Anyways, I have another question. For simple 2D meshing, consider an example where you have a smaller square at the center of a bigger square. Using STAR CCM or STAR design how would you mesh the region between the two squares. Also how would you mesh an edge using STAR CCM or STAR design.

Ankur

tom October 30, 2008 13:43

Re: Flow past a ship model
 
"Additionally, during post processing when I open a velocity vector field and select all parts I see the vectors only at the ship model surface and at the inlet and outlet faces."

so you got a converged solution; then u must have have a volume mesh, no? did u create a plane section to view the extents of the solution field?

As regards meshing between star design and CCM just import the surface mesh created in Design into CCM. I think ure model was a simple case of subtracting the ship geometry from the fluid volume volume, putting on a surface mesh and exporting from design. a 3d mesh needs to be done in design and converted to 3d in ccm by projecting the the appropriate cells to a plane.

Hope this helps

Ankur Srivastava October 30, 2008 14:24

Re: Flow past a ship model
 
How do you project a mesh on to a plane?

anon October 31, 2008 18:30

Re: Flow past a ship model
 
Sound like your trying to visualize the fluid. Instead of selecting the parts of the ship or the domain in your scalar scene, create a plane through the domain and select it as the part (instead of the ship/domain surfaces). To create a plane, Derived Parts>Section>Plane.

name November 4, 2008 04:02

Re: Flow past a ship model
 
Create threshold as plane, then you will see all vectors pass from fluid cells :) between hull and walls..

good luck..


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