REGULAR AND BREAKING WAVES IN WAVE TANK FOR DISPERSION EFFECTIVENESS TESTING

摘要

The wave tank (32 m long X2.0m high X0.6m wide) at the Bedford Institute of Oceanography in Nova Scotia was used to simulate the propagation and breaking of deep water waves using a flap-type wavemaker. The water profile and velocity were measured using a wave gauge and an Acoustic Doppler Velocimeter (ADV). The wave periods of interest ranged between 1.18 and 2.08 seconds. A technique for generating breaking waves at the same location in the tank was used to obtain a spilling and a plunging breaker. We evaluated the energy dissipation rate at various depths in the tank for regular and breaking waves. Plunging breaking waves had heights of 0.25m. For the breaking experiments, the energy dissipation rate decreased from around 1.0 10~(-2) watts/kg a few centimeters below the surface to less than 5.0 10~(-4) watt/kg 20 cm deep in the water column. The regular waves had, on the average, an energy dissipation rate of 5.0 10~(-6) watt/kg deep in the water column. This indicates that breaking plays an important role in the dispersion of oil at sea.