Calculating noise level of sonic flow in a pipe 1

[LaSalle1940]

I have a situation where there may be sonic flow of (50 psig saturated) steam in a (2") pipe. This would occur rarely, but it would be useful to be able to estimate the noise level at some distance from the pipe. Can someone please provide the appropriate equation(s) and/or point me toward the correct source/authority for such equations? Thanks.

 

[GregLocock]

In the absence of any better suggestion, look at the power absorbed in the shockwave, figure out a coupling efficiency (don't know how) and then use intensity or the free field approximation.

p(success)~0 but you'd learn a lot.

I'm assuming this is a 'raspberry' noise?



Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[Hatch]

In a typical industrial setting, the steam flow in a pipe rarely generates problem noise levels. High noise levels are actually generated upstream at a valve or orifice. The turbulent flow/sound is then propagated down the pipe and out as noise. If you want to start somewhere then look up the pressure drop, flow rates etc across the valve or orifice and the manufacturer can usually supply the valve noise level or provide the equations.

 

[LaSalle1940]

Hatch,

Good suggestion for a starting point: after poking around, I found some graph-based data that allowed a reasonable estimate. At the same time, I also found analytical relations that allow estimation in a spreadsheet. Thanks.

 

[quark]

Check whether this link can be any use to you.

http://www.fisherregulators.com/technicalmonographs/various/

Monographs 33 and 43 can throw some light.