Controlling Salt Wedge propagation by using roughness elements

Abstract

The research aims to study the effect of using roughness elements in controlling the propagation of salt wedge upstream river mouth. The computational fluid dynamics, CFD, was used to simulate the propagation of salt wedge in a flume system with roughness elements, a cube shape of 1.5cm, arranged at its bed with different configurations. The roughness elements work to increase the flow turbulence that dissipates the salt wedge that moves beneath the fresh water and reduces its propagation. The results of the eight model runs showed that roughness elements can reduce the propagation up to 66.7% depending on the freshwater discharge and the bed slope of the flume. Roughness elements provide obstruction to the movement of the salt wedge and mixing of saltwater with the freshwater that helps to reduce the propagation of the salt wedge.