This is regarding the post processing with STAR CD. I tried to trace particle in two cases. In case 1, I have porous media in the flow field. The track stops when it reaches the porous wall in the field. I am not getting the full trace of the path. I tried with both forward and backward method ( from inlet and outlet). Is there any way to come out of this problem ?

Case 2 : This is with cyclic boundary condition. If the fluid enters from the inlet and leaves thru the outlet boundary the path is OK. If the fluid goes away on the cyclic boundary, there any more paths drawn (all discontinuous from one cyclic bc to other). Do we have any means to control this kind of plots ?

There's really no correct way to track particles through porous media, but I'm surprised it just stops. I'll have it looked into. On the cyclic boundary its doing exactly what its supposed too. Cyclic repeatability means that whatever goes out one boundary comes in the other. If you want this to not happen you can probably just change the boundary type (for post-processing only - don't run it) to symmetry.