Names of the Euler eigenvalues sets?
 

What are the proper names for the two eigenvalue sets for the Euler equations?

Is 'entropy wave' the correct title for the first set (u,v,w)?

What about the second set (V-a, V+a)? I've heard it called acoustic wave, sound wave, and pressure wave. Are all the names valid or is one of them the correct name? Or, is there a different name?

I don't know about a specific name, I think that acoustic waves is suitable (even if "acousti" recall to the linear case). For omoentropic flows you have also the class of Riemann invariant along them, so it can be "named" also Rieman waves