Block Diagnostic in Gridgen
 

I currently have a 2-D Mesh in Gridgen, I am ultimately planning on exporting to Fluent. My mesh is created but I want to check the Jacobians as I feel they are not all positive. How do I do this? Thank you in advance.

The reason may be that there is reverse in the direction of I index or J index. You can modify the direction in the block menu.

Hi fossu15a,

Lening D is correct - if your Jacobians aren't all positive it may just be a simple matter of flipping the I-J indices on your grid. Keep in mind that in order to do this, you have to have created a 2D block (in other words, only blocks can have their computational coordinates changed).

Other causes of bad Jacobians are the obvious issue of grid line crossing. In this case, any of the diagnostic functions in the Examine command can be used to check this (e.g. Area, skewness).