What is the function of a car muffler and how does it work?

[alexandria]

Homework Statement

im trying to understand how a car muffler works??

this is the pic that was in my lesson for a car muffler.

Homework Equations

no equations required

The Attempt at a Solution

i understand its purpose, i know its used in cars to dampen the noise produced by the gas coming from the combustion, but i don't understand how it works or how it is used to lessen the sound, can someone please explain in simple terms what a car muffler does and how it works?

 

[berkeman]

Homework Statement

im trying to understand how a car muffler works??
View attachment 99850
this is the pic that was in my lesson for a car muffler.

Homework Equations

no equations required

The Attempt at a Solution

i understand its purpose, i know its used in cars to dampen the noise produced by the gas coming from the combustion, but i don't understand how it works or how it is used to lessen the sound, can someone please explain in simple terms what a car muffler does and how it works?

That drawing looks like it is missing the packing material, which is a big part of the sound absorption process. Have you looked at wikipedia and HowStuffWorks to see what they say about how mufflers work? What did they say? Did they show packing material?

 

[insightful]

Many (most?) mufflers do not have packing:

http://www.paraglidingteam.nl/PPGTechnics/sound and noise/Mufflers/1155795969.pdf

 

[berkeman]

Many (most?) mufflers do not have packing:

http://www.paraglidingteam.nl/PPGTechnics/sound and noise/Mufflers/1155795969.pdf

Very interesting, thanks for that. I'm most familiar with exhaust pipes/mufflers on 4-stroke dirtbikes, which do use packing. But I see what the article says about the automotive mufflers and the method they use.

 

[alexandria]

"If you've ever heard a car enginerunning without a muffler, you know what a huge difference a muffler can make to the noise level. Inside a muffler, you'll find a deceptively simple set of tubes with some holes in them. These tubes and chambers are actually as finely tuned as a musical instrument. They are designed to reflect the sound waves produced by the engine in such a way that they partially cancel themselves out."

ok so what i am understanding from this, is that the car muffler is a set of tubes with holes in it. These tubes reflect the sound that is coming from the car engine, in a way that cancels most of the sound. This is a very broad understanding, but can someone explain it to me in more detail. The lesson that i am reading explained that a car muffler cuts the top half of the sound waves off, reducing its amplitude, therefore reducing the sound. A car muffler also relfects and absorbs sound coming from the engine to dampen the noise.
i need a step to step process on how this works, does the car muffler first cut the top half of the sound waves off in the process of clipping, what happens first, second, third?

 

[Nidum]

( Turn the sound down )