基于CFD的汽车空气调节系统离心风机流场与气动噪声数值模拟

Car HVAC centrifugal fan flow field and aerodynamic noise numerical simulation based on the CFD

基于CFD分析软件Star CCM+,结合计算气动声学理论,对某汽车空气调节系统(HVAC)离心风机工作过程的流场和气动噪声进行数值模拟分析.采用Reynolds平均数值模拟(RANS)标准k-ε湍流模型模拟稳态流场,利用大涡模拟(LES)湍流模型和FW-H方程分析瞬态气动噪声,通过监测离心风机内部和外部布置点测得压力脉动,并由傅里叶变换得到监测点声压级频谱.结果表明,离心风机主要噪声是叶轮旋转产生的离散噪声(达98 d B),可适当增加叶片数,调整叶片间距,以减小离散噪声.本方法可为其他类型风机的气动噪声数值模拟提供一种有效的分析手段.

Based on the CFD analysis software Star CCM ＋ combined with computational aeroacoustics theory,the flow field and aerodynamic noise of a car heating,ventilation and air conditioning（ HVAC） centrifugal fan were numerically simulated. The Reynolds average numerical simulation（ RANS） standard k-ε turbulence model was used to simulate the steady-state flow field; the large-eddy simulation（ LES） turbulence model and the FW-H equation were used to analyze the transient aerodynamic noise by monitoring the internal and external layout points of the centrifugal fan. The pressure pulsation was measured,and the spectrum of the sound pressure level at the monitoring point was obtained by Fourier transform. The main noise of the centrifugal fan under this operating condition was the discrete noise generated by the rotation of the impeller which was98 d B. More blades can be added and blading pitch can be adjusted to decrease the noise. This method can provide an effective analysis method for numerical simulation of aerodynamic noise of other types of fans.