高速面铣削过程中的噪声严重影响工作人员的健康,偶极子声源是气动噪声的主要声源,基于Ffowcs Williams-Hawkings(FW-H)方程建立高速面铣刀气动噪声预测模型,采用计算流体动力学(Computational fluid dynamics,CFD)的方法对气体流动特性进行数值模拟,进行高速面铣刀空转噪声测试试验,噪声预测声压级比噪声测试声压级低4.0 dB左右。研究结果表明容屑槽区域和刀片前刀面是影响高速面铣刀气动噪声的主要因素,高速面铣刀气动噪声在轴向具有明显指向性。结合频谱分析发现紊流噪声分布在较广的频率段,决定了气动噪声的大小,但旋转频率上离散噪声的强度往往很大。高速面铣刀气动噪声预测模型可为低噪声高速面铣刀设计和合理应用提供理论依据。
The noise produced by high speed face milling is detrimental to the machine operators.The major source of aeroacoustic noise is primarily dipole in nature.A noise prediction model based on Ffowcs Williams-Hawkings equation is used to predict aeroacoustic noise in face milling cutters.Numerical simulation of air flow in the milling cutter system is performed by using CFD method.The predicted sound pressure level based on mathematical model is 4.0 dB lower than measurement results at 9 000 rpm.And the error is about 7%.The chip flute region and insert rake face are found to be important factors in determining aeroacoustic noise in rotating face milling cutter.The directivity of aeroacoustic noise is verified in the axial direction.The broadband noise spreads over a broad range of frequencies and contributes significantly to overall noise,but the discrete noise at the rotational frequency is significantly higher.It can provide theory for low noise design and prediction of high speed face milling cutter.