Characteristics of wave pressure on an inclined plate

Abstract

In this study, the hydrodynamic pressure of regular waves acting on an inclined plate was experimentally investigated. Particle image velocimetry was used to acquire the velocity field in front of the inclined plate. Comparison of the results obtained by the linear wave theory revealed the effects of various factors, including the plate angle, wave steepness, and wave period, on the pressure profile. The pressure gradient along the plate above the still water level was analyzed to demonstrate the feasibility of the straight-line pressure distribution. Dynamic mode decomposition was used to explain the modal composition of the wave pressure evolution within a period. For large wave steepness, the second-order mode dominated at the bottom, resulting in a negative pressure at the wave crest. This phenomenon was reflected as two consecutive peaks in the pressure-time history, which are referred to as double humps. When the plate was inclined in the same direction as the incident wave, the wave became steeper, and the value of the dynamic pressure gradient increased near the still water level. However, this effect was not observed when the inclination of the plate was opposite to that of the incident wave.