Development of particle image velocimetry for water wave studies

Abstract

A wave measuring facility based on particle image velocimetry is described. The most important aspects of recording the flow field and the subsequent evaluation of the records is considered from a theoretical and practical point of view. The main sources of error are discussed and the performance of the system evaluated in terms of reliability and accuracy. Measurements of the internal kinematics of an extreme plunging breaker are made and the results shown to compare well with velocities predicted from a numerical model of a similar wave. The flexibility of the technique is illustrated with two further applications to vortex shedding behind a cylinder towed through a tank of stationary water and acoustic streaming within a cylindrical glass tube.