Modeling and analysis of aerodynamic noise in milling cutters

Aerodynamic noise generated in high speed face milling cutters is usually much higher than the noise exposure limit set by OSHA. Experiments were conducted on two different face milling cutters to understand the aerodynamic noise generation in face milling cutters. It is observed that dipole sources of noise are most important in determining the noise generation in rotating face milling cutters. The aerodynamic noise spectrum consists of discrete tones at the rotational frequency and a broad range of higher frequencies, with the broadband spectrum contributing significantly to overall noise. A mathematical model based on the Ffowcs Williams-Hawkings Equation is used to predict (un-weighted) aerodynamic noise. The noise predicted compares well with the experimental observations. The cutter gullet shape was found to be an important factor in determining broadband noise.