[ander]

Hi all,

I'm investigating possible ways that the aerodynamics around a projectile modelled as a rigid body could be solved. This would consitute a coupled 6DOF/CFD solver. The main challenges are related to the CFD simulation.

The mesh will obviously have to follow the projectile since meshing its entire flight path would be infeasible. This means that the mesh will at least have to undergo unsteady translation, and fictitious body forces would be appropriate to account for linear acceleration of the mesh.
At this point a choice has to be made. Shall the projectile rotate inside the mesh (which would require a chimera grid or perhaps ALE formulation with remeshing or some kind of immersed boundary method), or is it better to let the grid rotate rigidly with the projectile? The latter approach would require fictitious forces associated with rotation in addition to translation and would make it more complicated to impose farfield boundary conditions. The flow equations would be solved in the body frame of the projectile.

The latter approach seems more elegant and computationally efficient in my view, but there may be reasons that make it impractical. Please give me your opinions!