Joukowsky Equation: Applies to Gases Too?

[lambdaLoverD]

Hello everyone.
How do you do ! - this is my first post here.

A fluid dynamics question : do you know if the famous Joukowsky equation ($$\Delta P = \rho a \Delta V$$ ) applies to gases too ?

I have found a huge number of publications which mention the Joukowsky equation in relation to water hammer, i.e. the pressure wave(s) generated by a sudden closure of a valve in a water pipe.

On the other hand a similar phenomenon occurs with gases (although the pressure wave has lower amplitude). e.g. steam hammer. But very few publications mention it 0_o.

Does it have another name ? a different mathematical description (since gases are compressible) ?This paper seems to indicate that the equation works for liquid+gas mixtures
http://www.ipt.ntnu.no/~jsg/publikasjoner/papers2002/Houston2002PressurePulse.pdf
But how about gas only ?

Any hint is welcome
Thanks

 

[Dale]

It is just a fluid dynamics question, so it will work for any fluid regardless of if the fluid is a liquid or a gas. The difference between liquids and gasses is compressibility, and this form of the equation was derived assuming a compressible fluid so it will work fine for a gas.