柴油机怠速进气量对燃烧噪声影响的试验研究

Experimental study of air inflow on combustion noise of diesel engine in idle condition

为了降低怠速工况下柴油机的燃烧噪声,针对怠速进气量(节气门开度)对柴油机燃烧噪声和整机1 m噪声的影响进行试验研究,分析节气门开度对缸压、压力升高率(简称压升率)、机体燃烧噪声、整机1 m平均噪声及转速波动的影响。结果表明:节气门开度减小时,缸压及压升率随之降低,特别是压升率降低较为明显,燃烧噪声和整机1 m噪声均明显降低;节气门开度低于5%时,柴油机的转速产生了明显的波动,导致怠速不稳定。

In order to reduce the combustion noise of diesel engine under idle condition,the influence of idle air intake(throttle opening)on the combustion noise of diesel engine and the 1 m noise of the whole engine is experimentally studied.The influence of throttle opening on cylinder pressure,pressure rise rate,combustion noise,1 m average noise of the whole engine and speed fluctuation are analyzed.The results show that when the throttle opening is reduced,the cylinder pressure and pressure rise rate also decrease,especially the pressure rise rate decreases significantly,and the combustion noise and 1 m noise of the whole engine also decrease significantly;when the throttle opening is less than 5%,the speed of the diesel engine fluctuates significantly,resulting in unstable idle speed.