一、前言内燃机是一种热机,在反复进行“吸气-压缩-燃烧-膨胀-排气”的工作过程中,使燃料的化学能转换为机械能。但是,在这种能量的转换过程中,有一部分能量成为废热和噪声,通过排气管等渠道排放到大气中。内燃机的排气噪声特性,取决于内燃机的热循环和结构,基本上是一种随着高温脉动气流而产生的间断性噪声。因此,在以这种噪声作为基础 I. INTRODUCTION The internal combustion engine is a kind of heat engine. During the process of “suction-compression-combustion-expansion-exhaust” repeatedly, the chemical energy of the fuel is converted into mechanical energy. However, during the conversion of such energy, a part of the energy becomes waste heat and noise and is discharged into the atmosphere through exhaust pipes and other channels. The exhaust noise characteristics of an internal combustion engine are basically a kind of intermittent noise that occurs with high temperature pulsating airflow depending on the thermal cycle and structure of the internal combustion engine. Therefore, based on this noise