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claudia February 17, 2003 10:36

plotting results
Hi everybody!!! My geometry consist of two solids that share a common face. I defined the bounding solid for the fluid domain as Solid 1 and 2, then I created the fliud subdomain with solid 2. I defined the BC at the inlet of Solid 1 and at the outlet of Solid 2. But i want to plot results on the common face between them. I can't do it by defining a plane in the post, neither a simple user surface because this surface is complicated, .... Somebody can tell me what to do please?


Bob February 18, 2003 09:28

Re: plotting results
Hi Claudia, you can define your own surface in post, even if it is a complicated surface. Look at post and read how to generate user defined surfaces. If I remember correctly you can define a surface as a series of points (x,y,z) and a connectivity list. So the next problem is, "How do I get this surface and its connectivity list ?" You can create in build, using the patran mesher, a surface mesh (hex-mesh) on your surface that joins the 2 solids. If you export this mesh as a neutral file, you should be able to work out which are the points and which are the connectivity lists. extracting these from the neutral file should then enable you to put them into the correct format for post to read in as a user defined surface. I hope this isn't a case of over kill for your problem ? Alot depends upon the complexity of the interfacing surface. Bob

Claudia February 18, 2003 09:58

Re: plotting results
Hi Bob! I know how to create a user surface in post, but i donīt understand what you mean with "connectivity list". I created the surface with points (x,y,z) in a txt file, I got this points from the build. The problem is when I asked for a vector plot on the surface (with velocity as variable) the post returned only four vectors that corresponds to the points which i used to define the surface , I expected a lot of vectors over the entire surface (just like happen in a boundary) but it seems like there are only four nodes on the surface. This is what you mean with "connectivity list"? Can you please explain me this?... Thank you a lot!!!!

Bob February 20, 2003 14:53

Re: plotting results
Hi Claudia, Yes sounds like you got a single face to work using the user surface. Now what you need to do is create multiple faces, so that you will have lots of nodes. Then you will be able to get your desired vector plot. This is why I suggested using the patran surface mesher to generate a hex mesh with the connectivity list (or what ever its called) for your interface between the 2 solids of your domain.

There may be an easier way to do this ?? can anyone else suggest anything ?

The connectivity list, as I call it, tells you which node is conected to the next node that is used to define the face. When you export a patran surface mesh as a neutral file, exporting only the mesh details, you can extract the node coordinates and the connectivity. By doing this you can create a user surface of thousands of faces, which you can then read into post.

Hope this helps


Sameer Ghalsasi March 4, 2003 18:27

plotting results
hi everybody!! can you please tell me how to create user defined surface? for plotting the results in CFX post we need to create a "Poly Line" and as per my information there are two ways to create a polly line,namely: boundry intersection method and form file method with the BI method one can plot only those values of a particular variable which lie on the default boundry but i want to plot values laying inbetween the default boundry. Can you please tell me how to create a form file for getting these results? is there any way to extract the results interms of numerical values from CFX post processor? thank you

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