The acoustics of cavitation in spool valve with U-notches

Abstract

Spiral cavity produced by the swirling flow is observed in spool valve with U-notches. Individual bubbles with similar grown-up size appear in the wake of the fixed cavity. Consecutive bubble collapse produces frequency peak in the spectra, which decreases with the cavitation number. Vortex shedding occurs by the ‘break-off’ of the tail of the spiral cavity, the collapse of which affects significantly to those accompanied individual bubbles dynamics and acoustics. Rayleigh prediction to the bubble collapse time is taken, which is a bit smaller than the experimental result. The considerable viscidity effect of the oil medium is assumed as the predominant reason.