新型分流对冲排气消声器的阻力及声学性能研究

Resistame and acoustic performance study on the performance of a new split-stream exhaust muffler

针对1种基于气体分流对冲降低排气速度的新型结构排气消声器,使用计算流体力学的方法对其空气动力学性能进行分析。首先建立了消声器的仿真模型,并利用计算流体力学CFD技术对分流对冲排气消声器设定入口流速下的流场进行了仿真,分析了分流对冲排气消声器内部气体的流动特性和压力分布特性,并对新型消声器在不同入口气体速度下的压力损失进行模拟分析以及试验验证,并以CG25型单缸柴油机为样机,对新型消声器的声学性能进行了现场测试。结果表明:分流对冲排气消声器具有很好的空气动力性能,在柴油机标定转速下(2 200rad/min),新型消声器的插入损失为8.7dB,在柴油机不同工况下,新型消声器的插入损失高于原装消声器,证明了新型消声器具有良好的消声性能。

On the basis of the fact that air distributary can reduce its speed under the influence of the hedge, an exhaust silencer with a new structure is used to analyze the aerodynamic performance by computation fluid dynamics （CFD）. A simulation model of the muffler was built to simulate the flow field of air speed in the entrance, and to analyze the distribution of the air flow and the pressure in the muffle. At the same time, the pressure loss in the different air flow fields for the new type of muffler is simu-lated and tested. By taking a single-cylinder diesel engine CG25 as the experimental machine, the results show that the aerody-namic performance of this exhaust silencer is satisfactory, under the rated speed of diesel engine （2 200 rpm） , the insertion loss of the new muffler can reach 8.7dB, and under the different conditions of the diesel engine, the insertion loss of the new muffler is higher than the original muffler, the results demonstrate that the new muffler has a good performance.