基于壁面压力分布的消声器性能优化研究

Study on Muffler Performance Optimization Based on Wall Pressure Distribution

部分载货或牵引车辆由于底盘布置空间有限,需开发设计小型方箱消声器.基于理论及数值模拟逐步改进消声器内部结构,同时对改进的每种构型进行空气动力性能和声学性能的分析研究,获得其压力场、速度场、温度场,研究其阻力损失和噪声特性,探讨了结构因素对排气消声器性能的影响.逐步优化完成4种消声器构型,最终设计内插管接扩张孔管的小型方型消声器构型,利用排气管路的弯折和内插管的弯折进行排气的整体降速,内插管连接孔管,孔管直径越大,高速气体在其内部扩张降速越快,避免直吹壁面.改善消声器内部气流流动,避免气流对壁面冲击的应力集中.

Small square muffler need to be developed for laden or towing vehicles with limited chassis layout space. The internal structure of muffler is gradually modified based on theoretical and numerical simulations,and aerodynamic performance and acoustic performance of each modified configuration are analyzed and researched to obtain the corresponding pressure filed,velocity field and temperature filed,by which to investigate thoroughly the resistance losses and noise characteristics and explore the effects of structural factors on the performance of exhaust muffler. Four configurations of muffler are progressively optimized and a small square configuration with insert tube connecting perforated expansion tube is ultimately designed. By bending the gas exhaust pipe and insert tube to decelerate gas exhausting,the insert tube is connected with the perforated tube. The greater the diameter of the perforated tube is,the rapider the expansion and deceleration of highspeed gas inside the tube will be,to avoid the direct blowing of gas against wall surface. The airflow inside the muffler is improved to prevent the impact stress of airflow against wall surface concentration.