Numerical modeling of flood waves in a bumpy channel with different boundary conditions

In this paper, the Incompressible Smoothed Particle Hydrodynamics (ISPH) method is presented to simulate flood waves in uneven beds. The SPH method is a meshfree particle modeling approach that is capable of tracking large deformation of free surfaces in an easy and accurate manner. Wave breaking is one of the phenomena whose free surface is complicated. Therefore, ISPH method is a robust tool for the modeling of this kind of free surface. The basic equations are the incompressible mass conservation and Navier- Stokes equations that are solved using a two-step fractional method. In the first step, these equations are solved to compute velocity components by omitting the pressure term in the absence of an incompressible condition. In the second step, the continuity constraint is satifised and the Poisson equation is solved to calculate pressure terms. In the present model, a new technique is applied to allocate density of the particles for the calculations. By employing this technique, ISPH method is stable. The validation by comparison with laboratory data is conducted for bumpy channel with various boundary conditions. The numerical results showed good agreement with available experimental data. In addition, relative error is calculated for two numerical cases.