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Julian December 19, 2007 22:58

error in generating mesh in pro-am
I am doing a simulation on compressed natural gas direct injection engine for stratified mixture. The piston used is stratified surface type.

I have a problem of generating mesh surface with no errors in Star-CD pro-am.

After generating the stratified surface piston to igs form in CATIA, I imported the file into Star-CD pro-surf to create meshes automatically. There is free curves error happened at the outer boundary of the piston due to the bottom of the piston is not closed. The bottom of the piston must be open.

Then I continued to import the file generated in pro-surf into pro-am. A run check is done on the piston mesh surface and free edges error occured at the outer boundary of the piston.

Do anyone in the forum is doing the same project as I am?

Is the error above can be solved?

Can just continue with the generation of template for the piston in pro-am?

Thank you.

dong December 20, 2007 05:33

Re: error in generating mesh in pro-am
If you want to do CFD, you need a closed surface. if your piston is open, you cannot generate a mesh. Why does the piston have to be open?

Pauli December 20, 2007 17:55

Re: error in generating mesh in pro-am
Is your CATIA model the piston solid (steel/aluminum) or is it the gas volume?

You mention the piston bottom. This gives me the impression it is the piston solid model. If it is the solid model of the piston, that's your problem.

Ideally you need a CATIA model of the gas volume. Starting from the piston solid model, you can generate the gas volume ( the cylinder) in Pro-Am. Add line cells to the piton crown perimeter & use vcex with the vgen option. Delete all the stuff along the cylinder wall below the piston crown.

airfoil December 21, 2007 01:29

Re: error in generating mesh in pro-am
You need a volume of an object to start doing CFD. Your piston must has a thickness in order to start volume mesh.

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