One of the important functions of a car is to reduce noise, and the muffler plays a crucial role. Silencers can usually be divided into three types: impedance type, impedance type, and composite type, and the silencing effect of different materials will also vary.
The main components of a damping muffler include porous tubes and sound-absorbing fibers (sound-absorbing cotton). The sound absorption coefficient of sound-absorbing fibers will change with changes in physical properties such as density and diameter. In other words, the higher the density and smaller the diameter of the fibers, the higher the sound absorption coefficient. The magnitude of the sound absorption coefficient is related to the overall effectiveness of the muffler, and of course, multiple factors such as the cross-sectional circumference, effective length, and cross-sectional area of the muffler can also affect the noise reduction effect. The larger the circumference and effective length, the better the noise reduction effect.
How does resistance exhaust work?
The components of an impedance muffler include porous tubes and sound-absorbing fibers. When exhaust gas comes into contact with fibers through porous tubes, the fibers will vibrate, and friction and viscosity will be converted into heat energy, thereby converting noise into sound absorption process. Therefore, impedance mufflers are also known as sound absorbers.
Impedance mufflers have the characteristic of small size, so many original car drums tend to use impedance mufflers. If you want to fully utilize their noise reduction function, the installation position should usually be close to the engine direction. Numerous experiments have shown that impedance mufflers have better suppression effects on the mid to high frequency noise emitted by engines, but their effectiveness on mid to low frequency noise is relatively poor. On the contrary, resistive exhaust exhibits completely opposite characteristics to impedance mufflers.
Composite muffler
The structure of the composite muffler combines the advantages of the previous two types of mufflers, with both sound-absorbing cotton and an expansion chamber. As mentioned earlier, the above two types of mufflers have their own advantages and disadvantages at different speeds, and the composite muffler balances these two characteristics well and is widely applicable to various speed ranges. Due to its flexible volume design, it is not only more convenient, but also relatively expensive.
reactive muffler
The reflective muffler does not contain sound-absorbing cotton and is mainly composed of partitions and expansion chambers. There are usually three expansion chambers of different sizes. Utilize exhaust gas to reflect, interfere, and rub in these chambers to achieve the effect of eliminating noise. Large chambers are more conducive to handling noise, but their size is limited by the shape of the chassis. Compared to resistive mufflers, resistive mufflers have a larger volume and are usually installed at the rear of the vehicle. Resistant mufflers can significantly reduce mid to low frequency noise, making them highly favored by many original car manufacturers, such as Audi Q7 and BMW X5 SUVs, which also have a competitive advantage as a result.
The quality of car mufflers directly affects the driving experience, and the better the silencing effect, the better the driving experience. Therefore, having a high-quality muffler is crucial for car owners.
