发动机边盖辐射噪声仿真预测及实验

采取仿真预测与实验测量相结合的方法对某款发动机左边盖结构噪声进行分析。用LMS Test.lab测得发动机左边盖振动加速度信号，以此作为激励，导入到Hypermesh中对左边盖进行有限元分析。提取表面振动速度频谱，作为发动机边盖噪声辐射边界条件，运用LMS Virtual. lab对其进行声学仿真，并对噪声辐射仿真结果进行分析。再通过B&K 3560 D型数据前端对左边盖噪声进行测量，用波束成形法对测量结果进行分析，与仿真结果进行对比验证,两者声功率曲线吻合。对左边盖结构进行改进，再对改进后的左边盖进行噪声测量，整体噪声级呈下降趋势，改进效果显著。对边盖结构噪声预测以及整个发动机的降噪有一定参考作用。

Simulation Prediction and Experimental Test of Radiation Noise of Engine’s Side Covers

Used a method of combing simulation prediction and experimental measurement to analyze for the side cover structural noise of an engine, measured engine left shell vibration acceleration signal with LMS Test. Lab, which was imported in Hypermesh as an excitation to make finite element analysis of the left shell, extracted surface vibration velocity frequency spectrum as the engine left shell noise radiation boundary conditions, used the LMS Virtual. Lab to do acoustic simulation, analyzed the simulation results of the noise precision. The 3560D data front-end of B&K was applied to have a noise test for the left side cover, analyzed the data with Beamforming technology, compared with the simulation and verified the results, these two sound power curves were consistent. Made improvements in the left shell structure, then had a noise test on the improved left cover; the improved effect was proved significantly. It is of greater reference significance to predict side cover structure-borne noise and reduce the noise of the entire engine.