ABSTRACT
The depth-averaged Navier Stokes equations are numerically solved to simulate the flow around spur-dikes. There is usually recirculation at the downstream of the dike and this is considered as the main cause of erosion and accretion. The circulation phenomenon is investigated by using a two dimensional mathematical model. MacCormack explicit finite difference scheme is used which is second-order accurate both in time and space. The equations are 5oh·ed first by neglecting the eft'ecti,·e stresses and then by including the turbulent stresses. The computed results of the two models are compared with the experimental measurements, Nawachukwu [11], and then with each other. The model including the turbulent stresses is also tried for free-slip and no-slip boundary conditions at the solid boundaries and the results are compared. Comparison of the results show that proper estimation of eddy viscosity is necessary for the accurate prediction of recirculation.
