新能源汽车空调鼓风机气动噪声特性分析及优化

由于缺少发动机噪声的覆盖，新能源汽车空调鼓风机产生的气动噪声成为影响乘车舒适性的重要噪声源，主要针对某新能源汽车空调鼓风机系统进行气动噪声特性分析和优化，以适应更加严苛的噪声控制要求。采用ANSYS数值模拟软件和半消声实验室，通过对原始叶轮模型流场和声场的研究分析复杂的轮毂、叶片、气流和结构部件周期性相互作用产生的气动噪声特性，并开展轮毂型线和叶顶弧度对气动噪声的影响研究，其中轮毂型线模型最大可以分别降低43 阶次叶频噪声和总声压级5.0 dB和4.2 dB，叶顶弧度模型最大可以分别降低43 阶次叶频噪声和总声压级4.0 dB和2.7 dB。研究结果对优化新能源汽车空调鼓风机在受限空间内气动噪声控制具有一定的参考意义。

Influence of Specimen Area on Its Absorption Coefficient in Reverberation Room

The absorption coefficients of various commonly used sound-absorbing materials are measured in a reverberation room. The results show that reduction of the testing area of specimen from 10 12m^2 to 8m^2 only leads to less than 0.05 difference for the testing results, if the length to width ratio of the specimen is between 0.6 and 1.0. This difference is close to the measurement error. So a minimum test area of 8m^2 can be reasonably used. The results have significance for saving specimen materials.