Side branch resonance excited by flow in the main pipe

[dbday]

Hi,

I have a side branch on my 6"NB pipe which is 42.9mm i/d and 300mm long, it is terminated in a closed valve.
It is a natural gas pipe operating at 40 Barg / 15 deg C.

I am concerned that there may be some critical flow velocities in the 6"NB pipe that would cause a resonance in the side branch to give me a whistle effect.

Is there a way to work this out ?

Any help or references would be appreciated.

 

[btrueblood]

Google the terms "strouhal number" and "whistle"

 

[Strong]

Google this: "strouhal number vortex shedding" to calculate expected forcing frequency based on flow parameters and then calculate quarter wave modes of the side branch based on geometry and sound speed to see if there is a chance for a frequency match.

Walt

I did not want ot start a new thread with this response. Now how to deleate a thread?

 

[GregLocock]

red flag the new thread and explain what you want- easy!

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[dbday]

Thank you for the help.
I have found a paper called
Strouhal numbers of flow-excited acoustic resonance of closed side branches, Journal of Fluids and Structure, Ziada, S and Shine, S., 1999
It gives me what I need.
Cheers