Hello. I want Export grid from star-cd V4 to star-cd V3.26. If i try any format from EXPORT DATA-->EXPORT GRID i get this line: "**WARNING - CELL 544234 IS A POLYHEDRON AND THEREFORE CANNOT BE TRANSLATED.". When i try FILE-->SAVE AS CODED format i get next lines in v3.26: READ VERTICES FROM FILE star.vrt USING OFFSET = 0 STORE VERTICES 1 THROUGH 999999999 **ERROR WHILE READING VERTICES 0 VERTICES READ IN FROM FILE star.vrt MAXIMUM VERTEX NUMBER IS NOW 898795 0 IS MAXIMUM VERTEX NUMBER IN FILE Binary format make the same, just there is no line "**ERROR WHILE READING VERTICES"!! Any body have this problem or know the solve way?

The part of model placed here! It's 2d model. http://i17.tinypic.com/54alf2x.gif

seems like you got a polyeder cell in your model. V3.26 does not support those cells.

No, i have not polyhedral mesh. This model done in 3.26 pro-surf tetrahedral. After in prostar I delete all shells except up surface. Then I extrude it in 1 cell thick and then CELL REFINE in v4. All cells are hexahedral (cubic)

When you do the crefine instead of having couples on the interface between coarse and fine you actually get polyhedral n face cells. So in fact you have a polyhedral grid even if it looks hexa. Pick a cell with a "hanging node" and look at the faces... so the mesh you have there is now stuck in V4 for ever and ever amen...

the main problem is new new cell format in v4. Try nastran and/or Patran-form for the export.

If this doesn't work contact cd-adapco support. They might can help you with a small script which converts cell and vertex-file (only the old cell shapes) to older prostar versions.

it is possibly does not going to work with the polyhedral cell which star simply thinks it defined. simply remove the cell, export through patran read into the old version and make the cell by hand.

good luck matej

Murash,

You have to be VERY CAREFUL when moving meshes between v4.x and v3.26. Once you have taken a mesh from v3.26 into v4.x you can go back as long as you don't have ANY couples in the model (or crefine it). If you have couples and perfrom a geometry write (or if you perform a crefine) v4.x will split the faces of the master cell to match the faces of the slave cells and now that cell will become a polyhedral cell even though it may "look" like a hex/tet/prism etc. Then, as Ben indicated, this mesh is FOREVER & EVER a v4.x polyhedral mesh.

I HIGHLY suggest that you do a model save before doing any geom writes or crefines so that you can get the original (non-poly) mesh back should you need to modify it in v4.x.

Also, I believe that the database format has changed from v3.26 to v4.x so the databases are NOT backward compatible (i.e you can read a v3.26 database in v4.x but not vice versa). So, you need to export the v4.x mesh as *.cel, *.vrt, *.cpl files. Then Adapco can provide you with a Fortran program (cell423.f) that will convert these files from v4.x to v3.26. In this process it checks for polyhedral cells and if any will skip them. You will get v3.26 mesh files (cel, vrt, cpl) but where there was a polyhedral cell you will now find a hole/vacancy. This could create a lot of manual labor to repair to get back to your v3.26 mesh!

Shawn

I can not understand why the developer let V4-nastran-v326 instead of v4-v326.