Measurement of Velocities in Solitary Waves

The water surface profiles and corresponding water particle velocities of several solitary waves have been obtained. The measurements of the horizontal and vertical velocity components are conducted using a two-dimensional laser-Doppler velocimeter (LDV). Results are presented for three different wave height-to-depth ratios: ϵ = 0.11, 0.19 and 0.29. The experimental results are compared with existing theories which follow different orders of approximation, and the theories are found to agree well with the experiments. It has been convincingly demonstrated that the LDV measurement technique offers an unmatched advantage to determine the water particle velocities under water waves, especially in the region above the still water level.