Particle Image Velocimetry Measurements of Standing Wave Kinematics in Vicinity of a Rigid Vertical Wall

Abstract

The paper presents a detailed description of laboratory techniques and equipment used for measurements of a velocity field under regular standing surface waves in vicinity of a rigid vertical wall. The waves are generated in a closed flume by a monochromatic motion of a piston-type wavemaker and are reflected at a wall installed in a wave flume. A superposition of incident and reflected waves forms a standing wave. Particle image velocimetry technique is employed to measure evolution of a velocity field of wave-induced flow. The available data are used to calculate water particle trajectories of a standing wave system. Thus, a complete information on standing wave kinematics is obtained. The experimental results confirm that mass transport in Eulerian and Lagrangian sense cancels out in case of two progressive waves of lower steepness forming a standing wave. The experimental data may serve as a reference basis for theoretical models of waves interacting with vertical barriers. Moreover, important conclusions regarding the design of improved experimental setup leading to a better description of spatiotemporal velocity distribution under wavy surface are formulated.