This muffler is basically a combination of absorptive and reflective type and has 3 layers.
- The inner one content a converging and diverging type of venturi with holes on it and a flap (can be a rhodium/palladium) in between the C/D venturi which diverts the exhaust gases.
- Above the venturi is the outer body with holes to get the diverted gases outside.
- Gases from the outer body is then absorb by the absorptive material which is placed between the outer holed body and the outer shell.
When the gases get into the muffler they first pases through the converging venturi and at its end is a flap due to which the gases gets out from the holes present on the venturi and to reduce back pressure the flap too content holes.
Gases out of the venturi gets into the absorption material through the outer body that has holes on to it, the outer body is present to prevent the absorption material to get on to the venturi.
After absorption the gases gets into the diverging venturi and get out from the muffler.
The output noise of the muffler depends on
- length of venturi
- holes on the venturi
- flap elimination
and can be adjusted accordingly to the requirements.
The muffler also content a db killer which is detectable and can be used accordingly.
*** This Muffler is completely designed and manufactured by me.
The muffler i made was used on my FSAE vehicle which participate in formula SAE competition and other and was designed according to the rules of the competition.
The engine used was a KTM390 and my* criteria was to achieve the engine output ideal rpm noise to 95db without getting chock or overheat, which was successfully achieved also the noise at the max rpm was recorded 103db.
The muffler was also being tested on a Kawasaki 650twin but ot couldn't work the engine got overheated bcoz of the 390 parameters being used.
- My experience with the design was the parameters used to design the muffler can be used on the same engine or else the output may differ.
- The difference between the therotical and practical results are +-5db.
- I couldn't perform the simulation of the muffler including the absorption material, without absorption material results were different.
- The +-5db is because the holes on the venturi and outer body was same which was used in muffler but in calculations the holes size differ by 0.1mm.
- The overall weight of the muffler is same as the normal absorptive type muffler.
As this was my first prototype muffler with few errors in it, i haved already started with its upgrading and improving version with minimal errors and focusing to put it on sale just for the betterment of CV and nature.