Research papersRobust boundary treatment for open-channel flows in divergence-free incompressible SPH

- Exact specification of inflow/outflow boundary for open channel flow.
- Hybrid free-surface boundary treatment to minimize error in velocity divergence.
- The ISPH model can simulate laminar and turbulent flow alike.
- Provides smoothed and structured pressure variation.

A robust Incompressible Smoothed Particle Hydrodynamics (ISPH) framework is developed to simulate specified inflow and outflow boundary conditions for open-channel flow. Being purely divergence-free, the framework offers smoothed and structured pressure distribution. An implicit treatment of Pressure Poison Equation and Dirichlet boundary condition is applied on free-surface to minimize error in velocity-divergence. Beyond inflow and outflow threshold, multiple layers of dummy particles are created according to specified boundary condition. Inflow boundary acts as a soluble wave-maker. Fluid particles beyond outflow threshold are removed and replaced with dummy particles with specified boundary velocity. The framework is validated against different cases of open channel flow with different boundary conditions. The model can efficiently capture flow evolution and vortex generation for random geometry and variable boundary conditions.