Interlinked SPH Pressure Solvers for Strong Fluid-Rigid Coupling

Abstract

We present a strong fluid-rigid coupling for Smoothed Particle Hydrodynamics (SPH) fluids and rigid bodies with particle-sampled surfaces. The approach interlinks the iterative pressure update at fluid particles with a second SPH solver that computes artificial pressure at rigid-body particles. The introduced SPH rigid-body solver models rigid-rigid contacts as artificial density deviations at rigid-body particles. The corresponding pressure is iteratively computed by solving a global formulation that is particularly useful for large numbers of rigid-rigid contacts. Compared to previous SPH coupling methods, the proposed concept stabilizes the fluid-rigid interface handling. It significantly reduces the computation times of SPH fluid simulations by enabling larger time steps. Performance gain factors of up to 58 compared to previous methods are presented. We illustrate the flexibility of the presented fluid-rigid coupling by integrating it into DFSPH, IISPH, and a recent SPH solver for highly viscous fluids. We further show its applicability to a recent SPH solver for elastic objects. Large scenarios with up to 90 M particles of various interacting materials and complex contact geometries with up to 90 k rigid-rigid contacts are shown. We demonstrate the competitiveness of our proposed rigid-body solver by comparing it to Bullet.

Incompressibility Enforcement for Multiple-Fluid SPH Using Deformation Gradient

“…Moreover, reducing the gap between predicted and actual errors is worth future study. Recently strong fluid-rigid coupling techniques such as [27] have been proposed achieving impressive results. Integrating them into our incompressible multiple fluid framework worths investigation, for they may further enhance the stability and convergence at solid boundary.…”

A moving least square reproducing kernel particle method for unified multiphase continuum simulation

“…As different simulation methods need to work together, the interaction between them must be explicitly handled. The coupling between rigid body and liquid was handled in [Akinci et al 2012], and later improved in [Gissler et al 2019] with better performance in strongly coupled scenes. Sand and water mixtures were simulated in with two species solved on two grids coupled by a linear drag force.…”

Multi‐Level Memory Structures for Simulating and Rendering Smoothed Particle Hydrodynamics

“…SPH has been an active field of research since its introduction by Gingold and Monaghan [GM77]. Although initially only stiff equations of state were used to simulate weakly compressible fluids [MCG03, BT07], recent advances allow both divergence‐free and incompressible fluids [BK15, GPB*19], allowing for highly detailed and realistic fluid simulations. For a general overview of SPH methods, we refer the reader to [KBST19].…”