Mesh Coordinates
 

Dear CFX users,

Is it possible to pick the x,y, and z coordinates of a specific domain in CFX-Pre through CEL expressions? Also, does anyone know the syntax to be used in order to pass the coordinates of surface nodes for a specific domain using CFX Data Acquisition Routines?

Thanks.

Re: Mesh Coordinates
 

Dear Khaled & Noel,

What do you mean by pick?

You can use x, y, and z as CEL variables in any expression in CFX-Pre, CFX-Solver and CFX-Post..

What do you mean by passing the coordinates usign CFX Data Ac..routines?

You want to get XYZ for boundary nodes, and work with them? Then, you must call USER_MESH_GETDATA using the documented interface, and you will get a pointer to the array containing the coordinates of the nodes on a particular surface..

Have you read the CEL, and/or User Fortran documentation? I do agree is not extensive, but there is information for these particular questions..

Opaque..

Re: Mesh Coordinates
 

Thanks for the quick reply, and sorry for not explaining our problem clearly. We are trying to move the mesh of a mixer shaft in CFX. Our main problem, as of right now, is that we dont have any details as to how the mesh displacement equations are assembled and solved in CFX. When x, y, and z, are used in CEL expressions as input to a CEL subroutine, they are not all read at once. It seems that CFX reads x,y, and z on one location, then reads x,y, and z on another location, and so on until the whole domain is covered. What dictates this trend? is it the element types within each domain? What would save us alot of trouble is if x,y, and z, are read all at once, instead of the step-wise trend that we are witnessing. I hope this clarifies our problem.

Khaled & Noel

Re: Mesh Coordinates
 

Dear Khaled & Noel,

Not much it can be done about it. The ANSYS CFX solver request data as needed within its algorithm.. Sometimes it may be the whole boundary, or fraction of it. The UserCEL function to move a boundary should support either a full request (rare), or a partial request (most common).

What are you trying to move? A boundary, and let the mesh deform? or trying to move the whole domain at once and you impose the new locations (assuming same node connectivity)?

There is a tutorial where a full mesh is read in every time step, and another tutorial where the boundary is moved and the mesh morphed by the solver.

Opaque..