Natural dispersion of oil

Laboratory investigations were performed on the natural dispersion of surface and submerged oil. Surface oil broke up into droplets and penetrated the water column due to the effect of breaking waves. Submerged oil parcels (submerged spill) broke up into droplets due to turbulence in the ambient water. The experiments on surface oil dispersion led to the following quantitative relations:

• a)

  an empirical relation for the oil entrainment rate (dispersed oil mass per unit time), as a function of the oil type, oil layer thickness, breaking-wave energy and temperature;

• b)

  the droplet size distribution as a function of the above parameters;

• c)

  the intrusion depth of oil droplets related to the wave height.

The experiments with submerged oil resulted in relations for the droplet size distribution in dependence of various parameters. The empirical relations are applicable in mathematical models for calculation of natural dispersion of oil in the sea, with given hydrodynamic conditions and breaking wave statistics.