A multi-scale model for coupling strands with shear-dependent liquid

Abstract

Fig. 1. Left: A rotating brush splashing through thick oil paint. The inset shows a zoomed view of paint on the bristles. Middle: Melted chocolate poured onto a hair-covered cylinder that rotates to mimic the shaking behavior of mammals. Right: Soba noodles covered with oyster sauce pulled upwards by a fork.We propose a framework for simulating the complex dynamics of strands interacting with compressible, shear-dependent liquids, such as oil paint, mud, cream, melted chocolate, and pasta sauce. Our framework contains three main components: the strands modeled as discrete rods, the bulk liquid represented as a continuum (material point method), and a reduced-dimensional flow of liquid on the surface of the strands with detailed elastoviscoplastic behavior. These three components are tightly coupled together. To enable discrete strands interacting with continuum-based liquid, we develop models that account for the volume change of the liquid as it passes through strands and the momentum exchange between the strands and the liquid. We also develop an extended constraint-based collision handling method that supports cohesion between strands. Furthermore, we present a principled method to preserve the total momentum of a strand and its surface flow, as well as an analytic plastic flow approach for Herschel-Bulkley fluid that enables stable semi-implicit integration at larger time steps. We explore a series of challenging scenarios, involving splashing, shaking, and agitating the liquid which causes the strands to stick together and become entangled.

Hierarchical Optimization Time Integration for CFL-Rate MPM Stepping

“…quadratic B-spline basis to represent solutions on the grid, which is further verified by Wallstedt [2009] with manufactured solutions. In graphics, MPM has been shown effective for snow [Stomakhin et al 2013], sand [Daviet and Bertails-Descoubes 2016;Gao et al 2018b;Klár et al 2016;Yue et al 2018], foam Ram et al 2015;Yue et al 2015], cloth Jiang et al 2017a], rod [Fei et al 2019;Han et al 2019], sauce [Nagasawa et al 2019], fracture [Wang et al 2019;Wolper et al 2019;Wretborn et al 2017], multiphase flow [Gao et al 2018a;Stomakhin et al 2014], and even baking of food ]. More recently, coupling MPM and rigid bodies was explored in both explicit [Hu et al 2018] and implicit [Ding and Schroeder 2019] settings.…”

Fast and versatile fluid-solid coupling for turbulent flow simulation

“…Moreover, most particle methods do not ensure a consistent pressure in the fluid and on solids [Band et al 2018]. Finally, hybrid particle-grid methods often use grid-based techniques to handle coupling [Zhang et al 2016b;Fei et al 2018a;Hu et al 2018;Fei et al 2019].…”

“…Recent approaches have demonstrated efficient and realistic simulations of shells [Grinspun et al 2003;Bridson et al 2003] or rods [Bergou et al 2008] in viscous fluids [Fei et al 2018a;Takahashi and Lin 2019;Fei et al 2019], for which momentum transfer can be carried out both stably and efficiently using reduced models, as well as in non-turbulent flows through cut cells [Azevedo et al 2016]. Progress in kinetic approaches have even led to stable and much more efficient treatment of coupling in turbulent flows via a diffuseinterface immersed boundary method [Li et al 2019; alas, non-volumetric structures such as thin obstacles are not supported, greatly limiting the variety of simulation scenarios in practice.…”

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

“…Gao et al [2018a] simulated particle-laden flow. The coupling between hair and liquid was modelled in [Fei et al 2017], cloth and liquid in [Fei et al 2018], strands and shear-dependent fluid in [Fei et al 2019].…”