Acoustic analysis of silencer cavity

[elogesh]

Hai,

I have a silencer for automotive application.

I have to evaluate the noise attenuation characteristics of the silencer using numerical techniques.

I have choosen transmission loss as the parameter to express the noise attenuation characteristics of the silencer.The transmission loss characteristics is independent of the source and needs anechoic termination.
We used to give unit acoustic pressure at the inlet of the silencer and Impedence at the outlet.
But the concerned people, wants to give actual pressure pulation coming out from the cylinder head as an input to the silencer.How to proceed this problem? How pressure pulse data is going to help us in making a decision about noise attenuation? Whether it is possible to know the input pulse reduction within the silencer?

Whether the pressure data in frequency domain(Comparable with excitation force in vibration) and transmission loss(FRF)multiplication will give as the actual response of the silencer?

With Thanks & Regards,
elogesh

 

[GregLocock]

It'll be somewhere in the ballpark, particularly if you use insertion loss, not transmission loss. 5 or 10 dB errors are not uncommon, unfortunately.

The sad truth is that even using expensive software to fine tune our designs we still end up cutting and shutting them to optimise their acoustics.

Cheers

Greg Locock