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syd April 26, 2010 15:32

help with Baffles...
Hi everyone!

I am simulating a sailboat, with a mainsail and a jib: I managed to create a mesh that satisfies me, but it's huge(8 millions of cells of volume mesh), so I'm trying to reduce it; one way I read about was "transforming" the sails in baffles interfaces.

Untill now, I imported the 2 sails in CCM as .IGES files, with a thickness of 0.4 mm: in this way, everything works, but the resulting mesh is huge, as I said before, because of the very small thickness.

So, I tried to import them as superficies, with no thickness (as .IGES files): the software allow me to import them, but it warns me that they "are not solid": in fact, as I try to perform a boolean union (between the hull+mast+boom and one sail) I get an error message "not closed and manifold region", referring to the sail.

My question is: how do I handle my boundaries:
-wind tunnel
if I want to turn my 2 sails in 2 baffles with no thickness?

thanks to everyone!!!

kyle April 26, 2010 16:06

You are not going to be able to mesh the sail as a baffle in Star-CCM+, at least not easily.

You can try meshing the same way that you originally tried, but disable proximity refinement in the mesher. This way it will not create tiny cells all over the sail.

Vinicius April 27, 2010 17:36

Before meshing, right click at the boundary that have your "only surface" sail and click in convert to interfaces. Keep both in the same region, and in the node called interfaces, change the interface type from Internal Interface to Baffle interface. This allows you to generate a mesh without no manifold edges.

Try to see where these non-manifold edges are in your model, in the surface repair mode. They will be the blues edges.

Always check your surface to see if it has non-manifold edges/vertices, free edges and self-intersections.

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