SPH Modeling of One-Dimensional Nonrectangular and Nonprismatic Channel Flows with Open Boundaries

Abstract

In this study, the authors solve the shallow water equations (SWE) with smoothed particle hydrodynamics (SPH) for one-dimensional (1D) nonrectangular and nonprismatic channel flows with open boundaries. To date, 1D SPH-SWE has been only developed to simulate rectangular prismatic channel flows with closed and open boundaries. However, for practical hydraulic problems, channel cross sections are not always rectangular and prismatic. A general approach is proposed in this study to extend the engineering application range of 1D SPH-SWE to nonrectangular and nonprismatic channels with open boundaries by introducing the wetted cross-sectional area and the water discharge in SWE and combining the method of specified time interval with the inflow/outflow algorithm. Three benchmark study cases, aiming at testing various steady flow regimes in nonrectangular and nonprismatic channels, are adopted to validate the newly proposed approach. Through the investigation of the convergence analysis and numerical accuracy test of the study cases, the results show that the present SPH-SWE approach is capable to model 1D nonrectangular and nonprismatic channel flows with open boundaries.