Air Intake tuning?
Air Intake tuning?
(OP)
I do understand that intake runner length can be tuned to boost more air & hence, get more performance but,
difficulty to understand meaning of
"air cleaner system which has couple of resonator & side branches. Resonator 1 is tuned at 125 Hz, Resonator 2 is tuned at 140 Hz, Side Branch 1 tuned at 540 Hz & side branch tuned at 840 Hz."
I will appreciate, if anyone can reply
difficulty to understand meaning of
"air cleaner system which has couple of resonator & side branches. Resonator 1 is tuned at 125 Hz, Resonator 2 is tuned at 140 Hz, Side Branch 1 tuned at 540 Hz & side branch tuned at 840 Hz."
I will appreciate, if anyone can reply





RE: Air Intake tuning?
They will only have negligible effects on the volumetric efficiency if they are upstream of the plenum.
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Air Intake tuning?
But still I have confusion on,
(1) what is the physical significance of, resonator 1 is tuned at 125Hz or Side branch 2 at 840 Hz?
(2) How do we come up specific tuning frequency of different resonator & side branch for the same air intake system?
(like to improve the voulmetric efficiency,we calculate how long the intake valve will be closed & come up with runner length to get more engine performance)
Thank you in advance,
RE: Air Intake tuning?
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Air Intake tuning?
but does it mean that we had problem with interior & exterior noise. Afer that we came up with the solution do that we did tuning for Resonator 1 at 125 Hz , Resonator 2 at 140 hz or side branch 1 at 540 hz & side branch 2 at 840 hz. (kind of noise wanted to hear)
So what the actual process going on for Resonator 1 at 125 hz or side branch 2 at 840 Hz?
RE: Air Intake tuning?
Like for a quarter wave tube-
- positive pressure wave goes from beginning to end,
- positive pressure wave goes from end to beginning,
- negative pressure wave goes from beginning to end,
- negative pressure wave goes from end to beginning,
which means that it takes 4 transits of the tube for the situation to return
& for Helmoltz how the air traveling due to pressure difference throgh the neck area similar to single degree of spring damper system
still can't understand the exact meaning of Side branch 1 tuned at 540 Hz & 2 at 840 Hz,, & for the resonator 1,2 at 125 & 140 hz?
Thank you in advance,
RE: Air Intake tuning?
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Air Intake tuning?
& the only question i was asking that if side branch 1 is tuned at 540 hz so does it mean that air is vibrating 540 times per second in tube area? or what exactly it means?
& for the resonator 1 at 125 hz so air is vibrating at 125 times per second in neck area? or what exactly it means?
Rectify eroor, if necessary
RE: Air Intake tuning?
For a quarter wave resonator, pressure is constant at the neck, velocity oscillates at the tuned frequency. And at the closed end it's the other way around. And the length of the whole bit of kit is 1/4 the wavelength of the resonant frequency. You need really long resonators to target the kinds of frequencies that cause problems in cars, hence the other type used ...
A Helmoltz resonator is a bit like a tuned dynamic absorber (remember those from 1st year mechanics?). The cavity is like a spring and the air in the neck is like a mass. And if you do your sums you'll soon realise that they you can dial in some pretty low natural frequencies without requiring 5m of pipework. If you find an odd-shaped plastic can under your hood connected by a pipe to the airway with no apparent function, it'll be Helmholtz.
See also here http://en.wikipedia.org/wiki/Acoustics for a brief explanation of Helmholtz resonators.
RE: Air Intake tuning?
I'm not sure we're dealing with someone who has ever taken a mechanics course, nor for that matter, any other kind of engineering course, based on the numerous posts he's put up here...
RE: Air Intake tuning?