Published online by Cambridge University Press: 04 July 2016
In a recent paper the suggestion is made that “it would be sensible when discussing the flow to use a Mach number based on the actual propagation velocity in the given circumstances.”
This directs attention to the deeper question of whether or not a Mach number however defined is a rational parameter in terms of which to express effects of flow.
In certain cases the quantity γp/ρ occurs quite naturally, regardless of any physical interpretation that can be given to it.