Effect of ultrasonic vibrations on fluid in a channel (measurement of acoustic turbulence)

摘要

When an ultrasonic vibration is applied to the laminar flow in a rectangular channel, acoustic cavitation increases turbulence, and the transition to turbulent flow is promoted from laminar flow In this study, acoustic turbulence measurements in a square channel are presented in the Reynolds number range 1500 to 6000 to document the mechanism of the turbulence promotion by ultrasonic vibration. By applying ultrasonic vibrations into the laminar flow which was developed by the agitation or turbulence of cavitation bubbles, and consequently, the transition to turbulent flow from laminar flow was promoted in downstream. An eight fold increase in turbulence intensity was obtained when Re 1500.