Aeroacoustic noise simulation of face milling cutters and noise reduction method for non-uniform distributed indexable milling cutters

Abstract

The aeroacoustic noise generated in high speed face milling cutter consists of discrete noise and broadband noise contributing significantly to overall noise. A numerical simulation on air flow using computational fluid dynamics (CFD) method is developed through considering features of airflow and acoustic fields outside high speed face milling cutters. The airflow velocity distributions in the gullet region on milling cutter are analyzed. The locations and intensity of the sound source are obtained by computing the sound source item with the linear Euler equation. The sound pressure level is predicted using Ffowcs Williams- Hawkings (FW-H) formula based on the Lighthills equation. The noise spectra of different sources on cutter surface show that the cutter gullet and the insert rake faces are the dominant noise sources. The comparisons of noise spectra generated in milling cutters with equally spaced inserts and cutters with unequally spaced inserts show that the use of unequally spaced inserts can alter the distribution of sound power and decrease the discrete noise peak value at the fundamental frequency, thus the overall noise can also be reduced.