Mass flow relative to shell noise

[hafele]

I have two sets of mass flow rate data vs. crank angle. one mass flow rate has higher amplitude than the second set of mass flow rate data, but the average of the mass flow rate for both are the same. Would it be safe to say that the mass flow rate with the higher amplitude has more effect on the shell noise than the one with the lower amplitude, even though, their mean mass flow rate is the same (approximate delta of the amplitude is .06kg/s)?

 

[suryaP]

what is the specific application you are looking for.

Surya Prakash
Project Manager
surya@tecumsehindia.com

 

[hafele]

The application is for exhaust muffler.

Thanks for interest.

 

[GregLocock]

All other things being equal the one with the bigger pulsations will cause higher forces in the shell, so it would be expected to make more noise, but the frequency content of the two flows may not be identical, so you may get different excitation of dominant resonances.

Cheers

Greg Locock

 

[suryaP]

most of the suction and discharge muffler of compressor design acoustic analysis shows not much effect of flow.As greg mentioned more noise at higher flow rates due to stronger pulsation,if you can measure discharge pulsations for bothe the cases if it is si,ilar,muffler designed for higher mass flow rates can be used easily for lower mass flow rate.But if vertices formation is taking place in side muffler in both the cases flow induces noise due vertex formation the frequency will move to lower frequencies for low flow rates(lower amplitude flow).It is a interesting please update on latest issues on this.
Thanks

Surya Prakash
Project Manager
surya@tecumsehindia.com

 

[hafele]

Thank you GregLocock and Surya Prakask for your input. After some more testing, the one case with low amplitude shows some improvement in shell noise level, but not enough. I guest the .06kg/s delta wasn't good enough.

Thanks again