Missile Plume BC
 

I have a generic missile geometry which excludes the nozzle. However, my computational model needs to include some sort of plume that would be present if I were to simulate the flow with a nozzle.

My question is- what BC can I set at the base (see below) to provide a low-order emulation of a plume? Does anyone have any experience with this?

Freestream
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......................| <- BC for plume
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Freestream