Numerical modeling of free surface flow in hydraulic structures using Smoothed Particle Hydrodynamics

A meshless particle numerical model based on the Smoothed Particle Hydrodynamics (SPH) is developed and evaluated for two-dimensional simulation of free-surface flows passing through an orifice and over a sharp crested weir. A practical technique is introduced making the model capable of handling the inlet and outlet boundaries. This technique is able to impose known-inflow flux (as in sub-critical open channel flow) at the inlet boundary, while the inlet pressure/depth is automatically adjusted (without imposing any unwanted boundary reflection and pressure fluctuation). Solution stabilizer techniques, such as XSPH and artificial viscosity, are also employed to increase the accuracy and stability of the model, and their effects on the results are evaluated. The developed model proves to be able to reproduce the free surface complexity with good accuracy. A 3-D finite volume mesh-based model is also employed to verify the result of the present SPH model, showing quite compatible pressure and velocity fields.