Ok, I think I'm going about this right, but I wanted a sanity check to make sure I'm not going down a dangerous road.

Ok, I have a flow field around an aircraft (it's a large transport aircraft). I want to release a small projectile (~2", which is very small relative to the aircraft) from a specific point. It's safe to assume the particle doesn't affect the local flow field (because it's so small compared to the aircraft), and I'm ignoring any HT from the projectile to the surrounding air flow. The projectile is an odd shape, but for this level analysis it's safe to assume it's spherical.

My thought was to use a DPM. I could create a single injection at the right location and track it. I know DPM is typically used for small particles (water droplets, etc...) so I'm really wondering if it would be applicable to something this big. I was going to leave "Interation with Continuous Phase" off because I'm ignoring effects of the projectile onto the flow field and any heat transfer to/from the projectile, and use Steady Particle Tracking. Does this pass the sanity check for a quick analysis for the safe separation of a spherical projectile? I've never done this before, so does anyone have any recommendations that might help me along with this or keep me from doing something bad?

Thanks for your help, Jason

Oh, I forgot to ask one more question...

What's the recommended Drag Law for something this size at Mach 0.4 at Sea Level conditions (V~447ft/s, REd~475000)?

The manual mentions the: spherical, non-spherical, Stokes-Cunningham, and high-Mach-number laws, but doesn't make any comments about when you can use one over the other.

Thanks again, Jason