Numerical treatment of finite difference method for solving dam break model on a wet-dry bed with an obstacle

In this paper, we propose four different numerical methods for solving the Non-Linear Shallow Water Equations (NSWE), which are used to study dam-break flow over an obstacle. The discrete equations are formulated by applying various finite difference methods with filter involving wet-dry procedure. To validate our numerical model, several benchmark tests are carried out. Comparison of the computed results with the analytical and experiment data shows that our numerical model reproduces the flow with high accuracy. Moreover, we examine the effect of the shape and dimensions of the obstacle on downstream water height. Rectangular obstacles reduce downstream water height more significantly than triangular and trapezoidal ones. Downstream water height decreases non-linearly as obstacle height and width are increased. •The Nonlinear Shallow Water Equations are able to model the dam-break problem with an obstacle.•The Lax-Friedrichs, FTCS, MacCormack, and Richtmyer methods with filter have successfully solved the equations numerically.•The proposed wet-dry procedure gives the accurate result in dam-break phenomenon over a wet-dry bed.•Moreover, the proposed numerical model was able to accurately simulate fluid-obstacle interaction.