Dispersion of matter in homogeneous, time-dependent nearly-horizontal flows

Civil Engineering and Geoscience

Mass transport in gravity waves on a sloping bottom

In the present investigation the influence of bottom slope on mass transport by progressive waves was investigated both theoretically and experimentally. Theoretical considerations based on lineair wave theory show the greatest influence of the slope on the bottom drift velocities for relatively long waves and steep slopes. The numerical values, however remain rather small (influence less than 20%). In addition the experiments show that. in the cases examined. the bottom drift velocities are more determined by the local parameters than by the magnitude of the bottom slope. Considering the net bottom velocities. the discrepancy between the horizontal bottom theory (Longuet - Higgins) and experimental results is considerable. Taking into account the first harmonic of the local wave form and the small slope effect in horizontal bottom theory does show however the same tendency as the experimental results for relatively small depths.Civil Engineering and Geoscience