Anyone know any good websites on sonic flow/shock waves in piping systems?

Question

I'm trying to visualize shock waves for gas flow in piping systems (choke flow); but all there seems to be out there is for external flow (aeronatics). Is there a picture of a shock wave on a PSV or orifice plate for choked flow, I'm having trouble visualizing pressure waves for pipe flow, its easy to see for aircraft but not for gas flow in piping systems (restriction orifices, PSV's etc.).

Answer 1

If you have supersonic flow in a duct, you will get an oblique shock anywhere the duct converges, and a Prandtl-Meyer expansion fan anywhere the duct diverges.

For flow that is just at Mach 1, the oblique shocks will be infinitely weak, and will reflect back and forth off the walls in a specular fashion (i.e., as light would reflect).

http://en.wikipedia.org/wiki/Oblique_shock
http://en.wikipedia.org/wiki/Prandtl-Meyer_expansion_fan