Laboratory Study on Flow Characteristics during Solitary Waves Interacting with a Suspended Horizontal Plate

Abstract

A series of laboratory experiments were conducted to investigate the 2–D kinematic field evolution around a suspended plate induced by solitary waves. The plate–type structure was rigid and suspended above the mean water level, while the solitary waves were generated by the wave maker to simulate the nearshore tsunami waves. The ratio of incident wave height to water depth was in the range of [0.200, 0.333], and the structural suspended height was in the range of [0.067, 0.200]. The velocity field around the deck was measured using the non–intrusive image–based PIV (Particle Image Velocimetry) method. As a result, the flow evolution was categorized into three phases: green water tongue generated, green water overtopping, and flow separation. Flow evolutions in different conditions presented obvious similarities in general but several differences in detail. The measured maximum horizontal and vertical velocities were around 1.9 C0 and 0.8 C0, respectively, where C0 is the maximum flow speed of the incident wave. Ritter’s analytical solution for the dam–break flow problem was examined and compared with the measured data. The accuracy of this solution for the present subject is significant in the period of T ∈ (0.6, 0.9). The adequate experimental data are valuable as a benchmark problem for further numerical model refinement and the improvement of fluid theory.