Wave reflection from submerged rectangular obstacles: experiments and predictive formula

Abstract

This paper presents an experimental study on wave reflection from submerged rectangular objects (shelves) in a 2-D laboratory flume. Preliminary tests using resistive wire probes and an acoustic Doppler anemometer were first conducted to confirm that a piston-type wavemaker was able to produce sinusoidal waves in the channel, without significant reflection from the boundaries. Then, measurements of water surface displacements using the two-fixed probe method and considering the presence of submerged rectangular obstacles provided reflection coefficients for different wave parameters and submergence conditions. Dimensional analysis was conducted and a dimensionless relationship was obtained to describe the reflection coefficient as a function of the wave slope and the water-to-shelf depth ratio. This relationship can be potentially used to predict ocean wave reflection from submerged obstacles for similar conditions as those evaluated in the present study.