风扇宽频涡流气动噪声分析及降噪

Analysis of fan wide-band eddy aerodynamic noise and its noise reduction

为降低风扇的宽频涡流气动噪声,基于风扇气动噪声仿真流程和声比拟理论,采用流体仿真软件STAR-CCM+建立三维模型,计算风扇叶片时域脉动压力,并与声学软件LMS virtual lab扇声源分区合成的风扇叶片时域脉动压力对比,对风扇噪声进行仿真计算和整车噪声测试验证。将风扇护风罩与风扇叶尖间隙由15 mm调整为5 mm,并对比优化前后仿真计算与整车噪声测试结果。结果表明:STAR-CCM+软件计算的风扇叶片时域脉动压力曲线与声学软件LMS virtual lab扇声源分区合成的风扇叶片时域脉动压力曲线吻合度较好;LMS test lab软件仿真分析频谱与整车噪声测试结果声压级相对误差为0.56%,结果基本一致;风扇护风罩与风扇叶尖间隙由15 mm调整为5 mm后,仿真计算和整车测试噪声声压级均方根分别降低了约9.00、4.00 dB,降噪效果明显。

In order to reduce the wide-frequency vortex aerodynamic noise of fan,based on the aerodynamic noise simulation flow and sound analogy theory,a three-dimensional model is established by using the fluid simulation software STAR-CCM+,and the time-domain fluctuating pressure of fan blade is calculated,compared with the time-domain fluctuating pressure synthesized by LMS virtual lab,the fan noise is simulated and verified by vehicle noise test.The clearance between the blade tip and the air shield of the fan is adjusted from 15 mm to 5 mm,and the results of the simulation calculation and the vehicle noise test before and after optimization are compared.The results show that the time-domain fluctuating pressure curves calculated by STAR-CCM+software are in good agreement with those by LMS virtual lab compared with the results of LMS test lab software,the relative error of sound pressure level is 0.56%,which is consistent with the test results of vehicle noise,the root mean square of noise pressure level of simulation calculation and vehicle test noise is reduced by about 9.00 dB and 4.00 dB respectively,and the noise is reduced effectively.