How do the bits inside an exhaust pipe make it quieter?
2006-09-07 02:40:09 · 6 answers · asked by gogs 2 in Science & Mathematics ➔ Engineering
They are acoustically tuned chambers that are designed to cancel out (or filter) the noise created by the engine. The pulses that come from the engine exhaust are within a fixed range and the design tries to filter as many of these frequencies as possible.
Look up acoustic low pass filter or Helmholtz filter (or resonator)and you should be able to get some info in more detail.
This is similar to the low pass filters that are used in electronics.
2006-09-07 05:08:47 · answer #1 · answered by oil field trash 7 · 1⤊ 0⤋
Under normal use over a period of 2 to 3 years, the standard exhaust may develop rust perforation and the sound will change. If you cannot wait for this to happen naturally, you may just go ahead and drill the holes yourself, a couple at a time, in discreet locations. This will have a similar effect to removing the baffles. However you need to be warned of a down side to this too. You will loose some power and will also end up with higher fuel consumption. Exhaust pipes are fixed pieces of tuned equipment. They are not just pipes. There is a whole lot of Research & development which goes into each and every different model, tuning it just right for that particular engine. If you play with this equation you should be ready to sacrifice performance. If that is OK with you, go ahead.
2016-03-17 01:44:07 · answer #2 · answered by Anonymous · 0⤊ 0⤋
A car exhaust is a long pipe with often a centre box and rear box placed inline of the pipe. These boxes are much larger than the pipe and consist of several dividers within the box with holes in them (some round, some oval shape depending on design). These dividers are called baffles and they're basically there to slow down and quieten the sound of the escaping exhaust gases.
Hope that helps?
2006-09-08 12:15:13 · answer #3 · answered by Anonymous · 0⤊ 1⤋
The sound waves bounce around in there and get absorbed. Like putting furniture in an empty room. Lots of echo when it's empty. But when the furniture is in it absorbs sound saves. Some recording studios have baffles on the walls - in the old days anyway. Probably, use more modern materials now. It's a little like sending the sound waves through a maze.
2006-09-09 23:48:38 · answer #4 · answered by Mike10613 6 · 0⤊ 0⤋
They slow the exhaust and allow it to expand inside the muffler before exiting the tailpipe.
2006-09-07 03:44:28 · answer #5 · answered by Steve 1 · 0⤊ 1⤋
It is effectivetly sound proofing
2006-09-08 07:36:25 · answer #6 · answered by Anonymous · 0⤊ 0⤋