Exit Velocity of a Mach 2.2 Jet
 

This may seem like a simple question most of the members of this forum. I have some basic questions about 1) how to calculate the jet exit velocity of a Mach 2.2 C-D nozzle, operating at perfect expansion and at an underexpansion ratio (pexit/pambient = 2)?

Assuming this a cold jet.

Also I would really appreciate any insight into the physical meaning of Fully expanded Jet Mach number.

Thank you.