What is the internal structure of an exhaust muffler?

[MacColin]

An exhaust muffler generally consists of several parts including the exhaust pipe, connecting threaded sleeve, muffler cylinder, and cylinder core. Inside the connecting threaded sleeve, there is an oil-soaked asbestos sealing ring to prevent air leakage at the joint between the exhaust pipe and the muffler cylinder. The muffler cylinder is welded with seven partition plates, dividing it into eight muffler chambers (seven expansion chambers and one resonance chamber). The cylinder core features inverted triangular flow guide grooves and numerous small holes. Relevant information is as follows: 1. Mufflers can be categorized into resistive mufflers, reactive mufflers, and impedance composite mufflers based on their working principles. 2. Resistive mufflers primarily use sound-absorbing materials to reduce noise. The sound-absorbing materials are fixed on the inner wall of the airflow pipe or arranged in a certain pattern inside the pipe. When sound waves enter the muffler, most of the sound energy is absorbed. The advantage of resistive mufflers is their ability to reduce noise over a wide range of mid-to-high frequencies, particularly excelling in attenuating high-frequency sound waves.