Whistling Instability in Idling Circular Saws

Abstract

Whistling is a self-excited transverse instability that produces intense noise at a resonant frequency of a circular saw. Experiments were undertaken to examine the noise source dependence upon tooth shape, tooth number, rotation speed and the surrounding air pressure. The source model supported by the data is a self excited fluid-structure instability possibly with a wake oscillation sustained or enhanced by the blade motion.