[rst1993]

Can anyone pls explain what are entropy and vorticity waves? how are they different from acoustic waves?

[FMDenaro]

Originally Posted by rst1993

Can anyone pls explain what are entropy and vorticity waves? how are they different from acoustic waves?

From the analysis of the Euler equations, the eigenvalues and eigenvectors analysis say that iso-entropic as well as omo-entropic flows have an entropy wave associated to the second eigenvalue u (convective velocity).
That means that along the characteristic curves dx/dt=u you have constant entropy

[rst1993]

Originally Posted by FMDenaro

From the analysis of the Euler equations, the eigenvalues and eigenvectors analysis say that iso-entropic as well as omo-entropic flows have an entropy wave associated to the second eigenvalue u (convective velocity).
That means that along the characteristic curves dx/dt=u you have constant entropy

But I don't understand that why is the first and second mode of LEE are called vorticity and entropy waves.

[FMDenaro]

Originally Posted by rst1993

But I don't understand that why is the first and second mode of LEE are called vorticity and entropy waves.

check for Riemann invariants in some textbooks (Zucrow or LeVeque for example)