Author(s): Angela Ferrari; Aronne Armanini
Linked Author(s): Aronne Armanini
Keywords: No Keywords
Abstract: We present a robust, efficient and accurate SPH scheme that is able to track complex three-dimensional nonhydrostatic free surface flows and which produces an accurate and little oscillatory pressure field. The scheme uses an explicit third order TVD Runge–Kutta time integrator, together with a monotone upwind flux for the density equation. For the discretization of the velocity equation, a non-diffusive central flux has been used. In our formulation, there are no parameters to tune and there is no need for any artificial viscosity term. To assess the accuracy of the new SPH scheme, a 3D mesh-convergence study is performed for the strongly deforming free surface in a 3D dam-break and wave-impact test problem. Moreover, the parallelization of the new 3D SPH scheme has been carried out using the message passing interface (MPI) standard, together with a dynamic load balancing strategy, which is needed to improve the computational efficiency of the scheme. Thus, simulations involving millions of particles can be run on modern massively parallel supercomputers, obtaining very good performance, as confirmed by a speed-up analysis. The 3D applications consist of environmental flow problems, such as dam-break flows, overtopping flows over a sharp-crested weir and impact flows against a wall. The numerical solutions obtained with our new 3D SPH code have been compared with either experimental results or with other numerical reference solutions, obtaining in all cases a very satisfactory agreement.