单缸柴油机新型排气净化消声器流场特性研究

Study on flow field characteristics of the new exhaust muffler for a single-cylinder diesel engine

以某单缸柴油机为研究对象,提出一种新型排气净化消声器方案。基于计算流体动力学(computational fluid dynamics,CFD)技术对新型排气净化消声器及原排气消声器内部速度场、压力场、温度场以及再生噪声分布进行了对比研究分析。结果表明,新型排气净化消声器与原排气消声器相比,新型排气净化消声器内部速度场、温度场分布更加均匀,有助于尾气中碳烟颗粒的捕集。压力损失降低了约0.3 kPa,再生噪声最大值提高4 dB,整体再生噪声减小4.9 dB。

Taking a single-cylinder diesel engine as the research object,a new exhaust purification muffler scheme was proposed.Based on CFD(computational fluid dynamics)technology,internal velocity field,pressure field,temperature field and regenerative noise distribution of the new muffler and the original one were compared and analyzed.The results show that:compared with the original muffler,the distribution of velocity field and temperature field in the new one is more uniform,which is conductive to the capture of soot particles in the exhaust gas;the exhaust pressure loss is reduced by about 0.3 kPa,the maximum regenerative noise is increased by 4 dB,but the overall regenerative noise is reduced by 4.9 dB.