Study on SPH method-based numerical simulation of overland flow
[Objective]In order to simulate the hydrodynamic process of overland flow on the impervious boundary layer after rain-fall,[Methods]a rainfall-runoff model(SWE-SPH-RR)based on the shallow water equation(SWE)was developed.The SWE-SPH-RR model used a smooth particle numerical method to solve one-dimensional shallow water equations,which simulated rain-fall by varying the mass of fluid particles.A particle reconstruction technique was used to simulate runoff processes without the need to add inflow particles.Four rainfall-runoff cases without consideration of the infiltration process were simulated separately with the model,the effects of variables such as different rainfall intensities or terrain on the hydrodynamic characteristics of over-land flow were analyzed.[Results]The result indicated that,whether the rainfall was constant or not,the model was better able to capture the phenomena of supercritical/subcritical flows.The simulated and measured data were in good agreement in terms of discharge or water depth,with average relative errors all within 5%.Rainfall on three different slopes,the runoff generated on the steep slopes had a higher momentum and when it met the runoff on the gentle slopes,it appeared as a bump phenomenon in the flow chart.This was basically consistent with the trend of the experiments.The model was able to accurately model and show good performance in both complex terrain and mixed flow regimes.For the few numerical oscillation problems that occur in the outflow,it may be necessary to adjust the parameters of the artificial viscosity term or to use alternative outflow boundaries to re-duce the occurrence of oscillating waves.[Conclusion]Simulating overland flow in different terrain and rainfall patterns was made possible by the model′s simple framework and reasonably accurate computed result.It showed a certain level of depend-ability and feasibility.
rainfallnumerical simulationoverland flowSmoothed Particle Hydrodynamics(SPH)Shallow Water Equations(SWE)variable mass particlesparticle reconstruction technique
万方数据
维普
