基于近似模型的弹性背腔穿孔管消声器声学性能优化

Acoustic Performance Optimization of Perforated Tube Muffler with Elastic Back Cavity Based on an Approximate Model

弹性背腔穿孔管消声器利用声波和弹性管壁的耦合作用,相比于穿孔管消声器具有更好的低频消声性能。为了进一步提高该消声器的低频、宽频消声能力,采用遗传算法对其进行优化。首先,利用COMSOL有限元软件建立该消声器的传递损失计算模型。其次,分析弹性管壁材料对消声器低频消声性能的影响,并选取橡胶复合材料作为弹性管壁材料。再次,由于所采用的有限元模型计算耗时长,为节约时间资源,利用径向基函数(Radial Basis Function,RBF)神经网络方法建立近似模型代替有限元计算模型。最后,利用近似模型结合遗传算法进行全局寻优,获得该消声器结构参数的优化结果,并利用有限元模型验证优化的准确性。结果表明:优化后在100~1000 Hz低频段范围内弹性背腔穿孔管消声器消声带宽增加62%,且平均传递损失提高3.6 dB。

Because of the coupling effect of sound waves and elastic tube walls,the perforated tube muffler with elastic back cavity has better low-frequency muffler performance than perforated tube mufflers.In order to further improve the lowfrequency and wide-frequency anechoic capability of the muffler,the genetic algorithm is used to its optimization.Firstly,the transmission loss calculation model of the muffler is established by means of the finite element software COMSOL.The influence of the elastic material of the tube wall on low-frequency anechoic capability of the muffler is analyzed,and the rubber composite material is chosen as the elastic material of the tube wall.Then,an approximate model based on radial basis function(RBF)combined with the genetic algorithm is established to seek global optimization,and the optimization results of the structure parameters of the muffler are obtained.The accuracy of the optimization is verified by using the finite element model.The results show that the optimized perforated tube muffler with elastic back cavity has 62%increase in anechoic bandwidth and 3.6 dB increase in average transmission loss in the low frequency band of 100-1000 Hz.