Resolution-adjusted boundary particles for adaptive SPH

Abstract In this paper, we present a new approach for improving particle-based boundary handling in adaptive Smoothed Particle Hydrodynamics (SPH) fluid simulations. Traditional SPH methods often struggle to maintain accurate boundary conditions when particle sizes vary. Our method dynamically adjusts the sizes of boundary particles to align with nearby fluid particles, ensuring consistent interactions across different resolutions. We also introduce an enhanced boundary surface sampling technique that uses density gradients to initialize and optimize boundary particle positions after size adjustments. Through various experiments, our approach demonstrates improved surface detail accuracy and reduced unwanted fluid behavior near boundaries compared to non-adaptive methods, while maintaining computational efficiency. The source code and experiment setups can be accessed under https://doi.org/10.5281/zenodo.15519146 .