An innovative open boundary treatment for incompressible SPH

Abstract

SummaryAn innovative inflow/outflow boundary treatment has been proposed to be used in smoothed particle hydrodynamics (SPH). Among other strategies, it involves the use of extended regions at open boundary sections and a procedure to enforce the mass continuity constraint, as well as to minimize outflow reflections. This methodology has been coupled with a modified ‘particle shifting’ algorithm, so that the robustness of the method could be ensured at high Reynolds number regimes. Confined flow around a square cylinder with an open outflow has been selected as the flow problem to analyze the performance of the new method. Detailed comparisons with data available in the literature for a variety of mesh‐based methods have been made for two different values of the blockage ratio β, namely for β = 1/4 and 1/8, and a range of supercritical Reynolds numbers. The results obtained with the present implementation of truly incompressible SPH have demonstrated numerical accuracy comparable with that of other methods, as well as the success of the open boundary treatment. A direct comparison with previously published SPH results for a distinct blockage ratio, namely for β = 1/5, has also revealed that a major improvement has been achieved by the use of the method described in this paper. Copyright © 2015 John Wiley & Sons, Ltd.