Author(s): R. Wana; J. Hughes; D. Graham

Linked Author(s):

Keywords: Smoothed particle hydrodynamics; Boundary conditions; Lid-driven cavity flow; Dam break flow

Abstract: In this paper the SPH method is used to model single phase flows. The lid-driven cavity flow, still water tank and dam break flow are simulated. Results are in good agreement with analytical solutions and experimental data. Smoothed Particle Hydrodynamics (SPH) is a meshfree, Lagrangian, particle method. It was first invented to solve astrophysical problems, but has since been developed and used to model a wide variety of fluid flows. Also, it is particularly well suited to simulating flow problems that have large deformations or contain free surfaces. This paper describes the SPH method and its application to single phase flows with a free surface. Fortran code has been written to implement the method. The SPH method has been used in different flow simulations and results are in good agreement with analytical solutions and, when available, with experimental data. In this work, the SPH application to the lid driven cavity flow is described. We have performed simulations at Reynolds number (Re = 1000), with uniform particle spacing. Numerical results give good agreement with Ghia et al. (1982) data for different particle resolution. Adding a background pressure solved the problem of a hole in the particles, which appeared at the centre of the cavity when using the evolved density scheme at high Reynolds number. Simulations were carried out with various values of background pressure, in order to determine the most suitable value to use. It was found that modifying the density boundary condition enhances the results obtained. That is, by setting the density of the dummy particles to be the same as that of the solid wall particles, so effectively setting a zero normal density gradient at the boundaries, solved the problem of velocity oscillations in the simulation. Also, the method is applied to a still water tank and a dam break flow using an effective zero normal density gradient produced improved solutions without adding background pressure. Simulations of the still water tank established the density and pressure boundary conditions needed to obtain an accurate pressure solution. The presented results give reasonably good agreement with experimental data and are also verified by analytical and other numerical results available in the literature. The SPH method results proved to be convergent and accurate.

DOI: https://doi.org/10.3850/978-981-11-2731-1_324-cd

Year: 2018