# Speed of sound in vortical flows

1. Apr 19, 2013

### zak8000

hi there

I am currently working with linear flows and using a ultrasonic setup to determine the speed of sound in a linear gaseous flow. But I would like to know more about the speed of sound in a vortical flow. Unfortunately I haven't been able to find any good book with regard to my topic and was wandering anyone could offer a good book or paper to get me going

thanks

2. Apr 19, 2013

In an ideal gas, the speed of sound is always $a = \sqrt{\gamma R T}$ where $\gamma$ is the ratio of specific heats, $R$ is the specific gas constant and $T$ is the static temperature. It doesn't matter if it is vortical or quiescent or anything else as long as it is an ideal gas in this case.

3. Apr 20, 2013

### Bobbywhy

“Wave Equation for Sound in Fluids with Vorticity”

“Abstract
We use Clebsch potentials and an action principle to derive a closed system
of gauge invariant equations for sound superposed on a general background
flow. Our system reduces to the Unruh (1981) and Pierce (1990)
wave equations when the flow is irrotational, or slowly varying. We illustrate
our formalism by applying it to waves propagating in a uniformly rotating
fluid where the sound modes hybridize with inertial waves.”
http://arxiv.org/abs/cond-mat/0106255

4. Apr 20, 2013