EXPERIMENTAL STUDY ON THE ROLL WAVES FLOW VELOCITY AND PERIODIC PROPERTIES

Abstract

 In this paper, the roll waves flow velocity and periodic properties are reported based on the experimental results. The internal velocity profiles were measured using the PIV technique and the surface elevation were also measured by the ultrasonic distance meter to examine the periodic properties. The velocity profile of the roll waves flow is faster than the log-law profile. The dimensionless velocity gradient which calculates from the roll wave period, shear velocity and viscous sublayer thickness has strong relationships with Re number. Furthermore, the wave celerity of the roll waves shows like free fall phenomenon.