In view of the merits of reactive muffler and resistance muffler, the combination of resistance and reactive structures to improve the muffler performance are mainly studies in this paper.
In view that the reactive muffler in the high-frequency effect is poor, and dissipative muffler in the high frequency effect is very good, we use impedance composite design to improve the overall muffler effect.
The results show that the improved scheme is feasible to enhance the performance of muffler and noise elimination effect of impedance muffler in high frequency is better than reactive muffler. It also shows that muffler performance can be improved by the combination of different muffling units and the rational arrangement of the length of the pipe.
A third is to design a reactive muffler
that is tuned to suppress the pure tone frequencies.
There are two primary automotive exhaust muffler designs available in the market - absorptive mufflers and reflective or reactive mufflers
. Most automotive exhaust mufflers comprise of a shell, baffle plates, non-perforated or perforated pipes, absorption materials and end plates.
Reactive mufflers are commonly used in refrigerating and air conditioning compressors to reduce the gas pulsation generated by the suction and discharge systems.
Reactive mufflers are generally used to attenuate pressure pulsations since the small holes and porous materials of dissipative mufflers may become clogged with deposits (Soedel 2007) eventually.
Articles on acoustics cover sources of noise, sound levels and decibels, hearing and psychological effects, noise control criteria and regulations (including design of acoustic absorption) and building in reactive mufflers
. Some of the applications that deserve a chapter all to themselves include vibration in rotating machinery, regenerative chatter in machine tools, and helicopter rotor tuning.