# [ICEM] Volume Meshing with intended Voids

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 November 28, 2010, 12:31 Volume Meshing with intended Voids #1 Member   W.N. Anderson Join Date: Jul 2010 Location: Zürich, Switzerland Posts: 46 Rep Power: 15 Hello, I want to mesh a three dimensional domain with two regions which should be voided from volume meshing. "Voided" means that no mesh elements should enter the regions, which I separate using surfaces from the region which should be meshed. Now, both regions to be voided are of the same shape, a cylinder in the shape of a rhombus. I include here an image of a cutplane of my mesh. The lower void is successful, no mesh elements within the region in the shape of the rhombus. Directly above this rhombus should be a second voided region, which is unfortunately meshed (contrary to my efforts). My method for separating the meshed from the void regions is the same for both void regions. Only the lower void region was voided. Are there any obvious reasons why the lower region was successful and why the upper void region would have been meshed? How can I systematically tell the volume mesher to "not mesh in this region, please"?

 November 29, 2010, 10:53 #2 Senior Member   Stuart Join Date: Jul 2009 Location: Portsmouth, England Posts: 722 Rep Power: 25 Would putting ORFN materials points in the regions where you don't want any elements work for this?

 November 29, 2010, 11:11 ...Solved #3 Member   W.N. Anderson Join Date: Jul 2010 Location: Zürich, Switzerland Posts: 46 Rep Power: 15 Thanks, that is an interesting thought about the ORFN material points. I solved this by installing more barricade surfaces (my "strategy" for voiding regions of the mesh) and then the key was to repair the geometry again (Geometry->Repair Geometry) as this step apparently informs the volume mesher as to where the volume is contiguous and where the volume is bounded.

 September 16, 2011, 04:31 #5 New Member   James Holland Join Date: Aug 2011 Posts: 2 Rep Power: 0 Hi Simon I have created my cubic surfaces I want to mesh inside. I have created a material point inside the cube but it is not where I want my aerofoil that I am testing because the point is in the top corner. Is this crutial to where my part is located in this volume or not? Thanks James

 September 16, 2011, 08:38 Material point location #6 Senior Member     Simon Pereira Join Date: Mar 2009 Location: Ann Arbor, MI Posts: 2,663 Blog Entries: 1 Rep Power: 46 The material point needs to be in the volume of the region, but it can be anywhere in the volume. It should not be on the surface of the volume because then it may not be clear which volume it is in (sitting on the fence). I usually shoot for roughly the mid point of the volume by using the midpoint method and selecting points on opposite sides. If I were doing a wing, I might select a point on the wing tip and a point on the furthest corner of the far field. I didn't understand what you were saying about the location of your airfoil... If this material point is supposed to be the solid material of your airfoil, then it needs to be within your airfoil. __________________ ----------------------------------------- Please help guide development at ANSYS by filling in these surveys Public ANSYS ICEM CFD Users Survey This second one is more general (Gambit, TGrid and ANSYS Meshing users welcome)... CFD Online Users Survey