# controlling unstructured mesh growth

 Register Blogs Members List Search Today's Posts Mark Forums Read

 October 21, 2005, 14:53 controlling unstructured mesh growth #1 tucker Guest   Posts: n/a I'm wondering if any of you have had any difficulties controlling the growth rate of unstructured volume meshes. I have a simple 3D cube and I'm trying to increase volume element size as you move across the cube. I've specified the mesh distribution on my edges, and even the mesh on the faces of the cube look good. However when I mesh the volume, the interior mesh quickly blows up rather than gradually increasing in size from one side to the other. I've tried looking for some method to control the volume growth (like an option I can select), but have been unsuccessful. Do you all have any ideas? Thanks!

 October 22, 2005, 11:28 Re: controlling unstructured mesh growth #2 Jason Guest   Posts: n/a This is an issue with the unstructured meshing algorithm built into Gambit. There are ways of controlling it (by decomposing the volume and I believe there is a default value to help smooth this growth out), but even that's not great, and it's a pain in the a\$\$. Use sizing functions. It's under the tools. They're described pretty well in Gambit's modeling guide. I'll use the "Fixed" sizing function as an example. For this, you pick a source (which can be one or multiple vertices, edges, faces, or volumes), an attachment (which for you would be your cube... it's the geometry you want the sizing function to act across) a Start Size, growth rate, and size limit. So lets say you want a .1 mesh that grows at 10% starting from Vertex.1 and acts across Volume.1 and it grows up to a maximum mesh size of 1.2. Then your source is Vertex.1, your attachment is Volume.1, your Start size is .1, your growth rate is 1.1, and your size limit is 1.2. There's better explainations of all the sizing functions in the Modeling guide. I also recommend looking up the presentations from the last UGM... there's a presentation on meshing tips & tricks, and has some pretty good information on sizing functions as well. Hope this helps, and good luck, Jason

 October 22, 2005, 16:36 Re: controlling unstructured mesh growth #3 James Guest   Posts: n/a Use Gridgen or ICEM CFD instead. Gambit sucks! James

 November 2, 2005, 15:27 Re: controlling unstructured mesh growth #4 tucker Guest   Posts: n/a Thanks Jason. That's really helpful...I'll give it a shot. Tucker

 Thread Tools Display Modes Linear Mode

 Posting Rules You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post Doginal CFX 2 January 12, 2014 07:21 sc298 OpenFOAM Native Meshers: snappyHexMesh and Others 2 March 27, 2011 21:11 Jingwei FLUENT 0 March 2, 2009 22:29 lr103476 OpenFOAM Other Meshers: ICEM, Star, Ansys, Pointwise, GridPro, Ansa, ... 12 November 24, 2006 06:56 Yingchun CFX 8 December 12, 2005 07:05

All times are GMT -4. The time now is 16:53.