Volume Controllable SPH

Abstract

We extend a Predictive Corrective Incompressible SPH (PCISPH) algorithm to a volume controllable SPH algorithm. In order to handle volume changes, we develop a method to control fluid volume. Our method precomputes a pressure correction factor of PCISPH at various particle volume and interpolates these factors to get a factor for arbitrary particle volume. Thanks to a PCISPH's high correctiveness, our method enables both stiff volume contraction and expansion. Additionally we derive computations for density and a force by pressure to prevent instabilities and unnatural flocks near interfaces between two fluids with different particle volume. Furthermore, granular simulators based on fluid simulators are also extensible to simulate volume change of granular materials.