[rmonaghan]

Hello,
I am about to start the following simulation work and I would appreciate any advice you can offer on what CFD package to use.

Our simulation is an axisymmetric laminar non-reacting piston-cylinder system, going through one compression stroke with a compression ratio of ~14. After compression, the piston is held in position for a long period of time. The piston head has crevices in it to minimise roll-up vortices into the bulk gas.

I am running ANSYS 12.1 on an academic licence, with the possibility that my system will be upgraded to ANSYS 13. I am aware that there are difficulties with meshes going through such a high compression ratio. A colleague has encountered huge problems using CFX mesh with CFX solver to solve this (problems caused by prismatic elements). He also tried ANSYS meshing tool with CFX solver and had similar problems (divergence near end of compression), but not as bad.

I use FLUENT 12.1 daily, but not for compressing mesh problems. Does anyone have any advice on what meshing and solver tools (ANSYS or otherwise) I should use for this simulation? As I said, our experience with (1) CFX mesh & solver and (2) ANSYS mesh & CFX solver has been bad.

Thanks very much,

Rory