共振式消声器声学性能三维时域计算及分析

摘要

The resonant muffler is an important measure to improve the intake and exhaust noise.The interaction between the flow and the sound is significant.The acoustic performance of resonant muffler was calculated with the three-dimensional time domain impulse method,which is based on the computational fluid dynamics (CFD) simulation.The CFD simulation results were verified by experimental results.The acoustic performances varying with different flow rates and temperature were analyzed.The results show that the peak at the resonance frequency declines and the transmission loss at the pass frequency moves gradually close to the resonance peak along with the increasing flow rate.Besides,the frequency characteristics shift to the higher frequency and the overall noise reduction effect declines.The resonance frequency shifts to the higher frequency,and the peak decreases with the temperature increase.Both the flow and temperature has more obvious effect on low frequency transmission loss than high frequency.%共振式消声器是改善进排气噪声的重要措施.基于计算流体动力学(CFD)的方法对共振式消声器声学特性进行计算,并通过有限元技术验证了模型与计算结果的准确性.研究流速及温度变化对共振式消声器传递损失的影响规律,结果表明:随流速增加,共振频率处峰值减小,通过频率处传递损失逐渐接近共振峰峰值,消声器频率特性向高频移动,整体消声量下降;随温度增加,共振频率向高频移动,峰值减小,带宽增加;流速、温度对低频处传递损失的影响大于高频.