Free surface tension in incompressible smoothed particle hydrodynamcis (ISPH)

In this work a Dirichlet pressure boundary condition for incompressible Smoothed Particle Hydrodynamics (SPH) is presented for free surfaces under surface tension. These free surfaces occur when the surrounding phase in simulations is neglected for computational reasons while the effects of the surface tension shall remain. We demonstrate capabilities of the boundary condition by comparing it to an approach from the literature. The simulations show that our approach provides a higher stability to the free surface, being capable of capturing static and transient processes as much as bubble coalescence. Furthermore a new approach is presented to compute the curvature more exactly for three-dimensional cases in order to stabilize the simulation, which is applicable for weakly compressible SPH and incompressible SPH simulations.