空调室外机气动噪声的数值分析

摘要

采用雷诺平均数值模拟方法对空调室外机内部的三维黏性非定常流动进行了计算,获取了用于噪声分析的气动声源.在此基础上,依据Lowson方程对脉动压力产生的气动声场进行了仿真,预测了空调室外机各部位气动声源对声场的贡献,并对锯齿轴流风叶的降噪效果进行了分析.为了识别偶极子声源,对固体壁面处的静压脉动进行了分析.结果表明:静压脉动的相位一致是采用偶极子声源强度进行声源识别的前提条件.室外机噪声数值预测结果与试验在定性上吻合较好,说明噪声数值分析方法具有良好的工程应用价值.%The unsteady three-dimensional viscous flow field of an air conditioning outdoor unit was simulated by Reynolds averaged numerical simulation with the polyhedral mesh solver algorithm in order to obtain the aeroacoustic sources.The Lowson equation was used to compute the acoustic pressure generated by the static pressure fluctuations at the rotating and stationary surfaces.Moreover, the noise contributions of the different parts of sources were analyzed, and the noise reduction effect of the saw-toothed blade was predicted.Based on the analysis of the pressure fluctuations, one can find that the pressures should have the same fluctuation phase for the source identification with the dipole source strength.The numerical results are in agreement with experiments qualitatively, indicating that the numerical method is available for noise prediction and reduction of air conditioner.