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colins December 11, 2003 01:29

user surface?
Hi,friends I want to define a surface on which some contour will be created.Howerver the problem is that I had not define a boundary conditon on it. Is the user surface function feasible£¿


Bob December 11, 2003 10:06

Re: user surface?
Yes, if its a simple surface then you can define it using the plane options in post. However if the surface is more complex then you amy want to generate a user surface. There are several useful way of doing this depending again on what you are trying to achieve. You can generate a surface from an existing boundary surface and translate this, or you can define you own more complex surface shape. This will require more work, and you will need the corect set of data points and their connectivity to generate a kind of surface mesh. Best thing to do is to check the help in post on what is necessary to generate this kind of surface. If possible try and use the other methods first.

Good Luck


colins December 12, 2003 22:13

Re: user surface?
Thanks,Bob. What I need is to split a surface in post,and I wonder if it can be realized in CFX5.6. btw,I have found the user surface data formatin the manual and I did defind a user surface.Another question,when I exported a surface,I only got the data point without their connectivity.

Bob December 15, 2003 07:04

Re: user surface?
The connectivity is the important part. Its like a mesh in build / ICEM. The number of points you define, determines the resolution of your plot. So you will probably need lots of points in a structured grid format with the associated conectivity. Like I said, its not the simplest method. It would be veery useful if CFX could develop a method for producing these grids within Post. I've done it previously by creating a surface in Build, used the patran mesher to create a surface mesh (structured) on the surface, exported as a neutral file, cleaned up the neutral file (including removing 1 from all the node / connectivity lists), then read it into Post. This could be done I should imagine within Post using simplified meshing tools and a surface import option ??? Hope this helps Bob

colins December 15, 2003 08:58

Re: user surface?
to Bob What I did is similar to yours.I created the surface in ansys and meshed it.Then I exported a mesh file containing nodes and elements and cleaned up the I can creat a user surface in post by read the data file. However,I don't think it is convienent. any way,thanks.

best regards colins

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