车内噪声统计能量分析预测与试验

阐述了统计能量分析方法的基本原理,利用统计能量分析(SEA)方法将某国产轿车划分为41个子系统,建立了国产某轿车三维实体模型。用解析方法计算了各形状规则子系统的输入参数,采用导纳法对复杂结构子系统的模态密度进行测试,利用稳态能量流方法测量了复杂结构的内损耗因子。计算了结构-结构、结构-声腔以及声腔-声腔间的耦合损耗因子。通过试验测量了动力总成振动和路面随机输入对车身的激励,并在消声室内对发动机舱声激励进行了测试,建立了被试轿车的CFD模型,对车外风激励进行了仿真计算。在上述研究工作的基础上,建立了该轿车的SEA模型,分析预测了车内噪声的1/3倍频程频谱,并与试验结果进行了比较,证实了本文所建统计能量分析模型的可信性。结果表明,所建立的SEA模型能够满足工程上在汽车产品开发设计阶段对车内中高频噪声分析预测要求。

Car interior noise prediction and experimentation using statistical energy analysis

The basic principle of statistical energy analysis(SEA) was demonstrated,some domestic car was divided to 41 subsystems using SEA,and the car 3D model was established.Input parameters of regular-shape subsystems were computed using analytical method,modal density of the complex structure subsystem was tested by admittance method,and damped loss factor of the complex structure subsystem was also tested by steady energy stream method.The coupling loss factor of structure-structure,structure-cavity,and cavity-cavity was computed.Engine excitation and road excitation were measured by road experimentation,and sound excitation of engine compartment was measured in the anechoic chamber.The CFD model of the car was established,and the exterior wind excitation was simulated and computed with the CFD model.Finally,the car SEA model was established,1/3 octave band spectrum of the car interior noise was predicted,and contrasted with experimentation result,credibility of the SEA model was confirmed.The results show that the model can meet the demand of middle-high frequency noise prediction in the car development and design stage.