NUMERICAL SIMULATION OF EXFOLIATION PROCESS OF SESSILE ALGAE BY MOVABLE BED SIMULATOR

Abstract

Construction of a dam promotes the decrease of the sediment transport, and the resultant development of the stable armor bed in their downstream river. Under such condition, the river bed tends to be less disturbed and the eutrophication develops. This river bed situation allows the sessile algae growing thickly over the stable armor bed, which has a bad influence on the environment. One of the measures to remove the sessile algae is a sand sprinkling over the stable armor bed. The sprinkled sand, which moves in saltation mode over the stable armor bed with scratching the sessile algae, makes the sessile algae removed from the armor bed. In this paper, the numerical simulation for the exfoliation process of the sessile algae under saltaion mode was simulated by the movable bed simulator based on the three dimensional distinct element method. Furthermore, the exfoliation process due to collapse of the armor coat under a high bottom shear due to a flood is simulated.