Helmholtz resonators

[jons999]

I am familiar with helmholtz resonators in an engines air intake plumbing but can anybody point me to a online reference of how they work and the theory behind helmholtz? I imagine them working sort of like a capacitor, absorbing the pressure spikes in the intake system, but i have also seen some located before the air filter, and they are not very well sealed to the air intake piping so i'm wondering how they actually do anything.

-Jon

 

[SpazyMoto]

I may be way off here but, I thought the Helmholtz resonator is a band stop filter. So it is used to keep noise down, I used this stuff when making big sub woofer boxes. See this page for some equations;

http://www.gmi.edu/~drussell/GMI-Acoustics/Filters.html

I hope this helps and of course I may be wrong...as usual.

 

[PFM]

Jon,

Take a look at How to Build Horsepower Vol. 2, by David Vizard. There are other books as well but this should give you the broad strokes.

Dave

 

[PanteraTurbo]

Jon,
You could also look here

http://www.grapeaperacing.com/GrapeApeRacing/tech/intakehelmholtz.cfm

. Good luck.
Blaine