# Volume calculation

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

 January 7, 2005, 05:28 Volume calculation #1 jf Guest   Posts: n/a Hi, I have to find the shared volume of 2 volumes. The first volume is an orthogonal 6 faces volume and the other is an arbitrary six faces volume. Is there an efficient way to do this ? I have to do this operation about 2e8 times. Thanks in advance for your advices. jf

 February 5, 2005, 07:31 Re: Volume calculation #2 x_flow Guest   Posts: n/a I think that is a computational geometry question. Maybe you can find a good answer if you should post it at a computational geometry forum or newsgroup. Do these volumes intersect?

 February 7, 2005, 10:58 Re: Volume calculation #3 jf Guest   Posts: n/a Hi x_flow, Thanks for your response. I've dropped this problem for the moment but I will be back on it in a few weeks. Yes, the volumes intersect. In fact, I want to (volume) average data from a mesh A to another mesh B which is uniform in the 3 directions. So I have to find which part (volume) of a cell of the mesh A belong to a cell of the mesh B. That's why I want to know the intersection of the 2 cells. You're probably right that I should go to a computational geometry forums and ask there (Are you familiar with forum in this field ? Do you know a *good* one ?). However since this is related to mesh calculation, I tought that someone here could respond me (Isn't it similar to certain tasks in the multigrid procedure calculation ?).

 February 7, 2005, 13:17 Re: Volume calculation #4 x_flow Guest   Posts: n/a You can try: comp.graphics.algorithms I now that similiar algorithms are used for colision detection which is a big issue in computer games and so on. If you need the exact volume of the intersection between two cells of arbritrary topology it might be bit difficult. If you only need an aproximation you can try to decompose the domain into cubes (defined size) and then test if they share both cells. This can be done using intersection tests of the centroid of the cube and both meshes (cells). There is a good book on these topics: "Computational Geometry in C" by Joseph O'Rourke.

 February 8, 2005, 16:55 Re: Volume calculation #5 jf Guest   Posts: n/a Yes, the computation of the intersections needs to be exact (conservative). Thanks for both references. I will give a look to them.

 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 zhengjg Main CFD Forum 10 November 12, 2012 00:13 paean OpenFOAM Running, Solving & CFD 0 November 14, 2008 22:14 SSL FLUENT 2 January 26, 2008 12:55 zahid FLUENT 4 June 1, 2002 09:11 Mark FLUENT 0 August 30, 2001 07:45

All times are GMT -4. The time now is 12:31.