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3-D Modeling Help

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I am trying to model a 3D mock fuel assembly (heat transfer and fluid flow). Attached is my model. I am trying to run my model but it seems that my meshing is creating way too many elements to run in any feasible time frame. I am quite new to COMSOL and would like to know how I can reduce the number of elements and degrees of freedom. I tried to set my meshing to extremely coarse and still my element size is 2 million plus.

Any tips or help would be great. I have tried some symmetry boundary conditions but I am doubtful I have implemented them correctly. When I run this model the model tends to freeze after the meshing is complete and hangs at 'Solving linear system'.



1 Reply Last Post Aug 3, 2011, 4:38 p.m. EDT

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Posted: 1 decade ago Aug 3, 2011, 4:38 p.m. EDT
Looks like your problem is that you have several areas that are overlapping/pertruding into each. I took an image of the joints in question and attached that file. What you need to do is make sure your structure does not "go into" each other like shown in the picture. What you want to do is to have each piece just touching one another, at the same x or y or z coordinate, wherever you are at in 3D space. Everything has to lineup, mathematically speaking in COMSOL in order for the mesh to work correctly. Off just a little bit and you will generate extra elements or not be able to mesh your object at all.
Looks like your problem is that you have several areas that are overlapping/pertruding into each. I took an image of the joints in question and attached that file. What you need to do is make sure your structure does not "go into" each other like shown in the picture. What you want to do is to have each piece just touching one another, at the same x or y or z coordinate, wherever you are at in 3D space. Everything has to lineup, mathematically speaking in COMSOL in order for the mesh to work correctly. Off just a little bit and you will generate extra elements or not be able to mesh your object at all.

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