The Granule-In-Cell Method for Simulating Sand--Water Mixtures

2025-04-01

AI Summary

Addressing the challenges of modeling particle migration, deposition, and clogging—along with ensuring volumetric conservation—in multiscale coupled simulations of sand–water mixtures, this paper proposes the Granule-in-Cell (GIC) method. GIC treats sand grains as a compressible macroscopic transport phase rather than rigid boundaries, unifying fluid–particle bidirectional coupling within a single mass-conservative framework that integrates the Discrete Element Method (DEM) and the Particle-in-Cell (PIC) approach. We introduce a novel multi-format interface force discretization strategy, enabling, for the first time in a unified model, high-fidelity reproduction of distinct dynamic responses of sand bodies under varying seepage conditions. Validated in canonical scenarios such as dam-break flows, GIC significantly enhances the physical realism, numerical stability, and volumetric consistency of full-process flow–deposition simulations.

Technology Category

• Constraint Satisfaction and Optimization: Mixed Discrete/Continuous Optimization
• Search and Optimization: Mixed Discrete/Continuous Search
• Planning, Routing, and Scheduling: Mixed Discrete/Continuous Planning

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• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs
• User Modeling, Personalization and Recommendation: User modeling and simulation for interactive and conversational systems
• Systems and Infrastructure for Web, Mobile and WoT: Data management and stream processing for Web, mobile and wireless applications

Abstract

The simulation of sand--water mixtures requires capturing the stochastic behavior of individual sand particles within a uniform, continuous fluid medium, such as the characteristic of migration, deposition, and plugging across various scenarios. In this paper, we introduce a Granule-in-Cell (GIC) method for simulating such sand--water interaction. We leverage the Discrete Element Method (DEM) to capture the fine-scale details of individual granules and the Particle-in-Cell (PIC) method for its continuous spatial representation and particle-based structure for density projection. To combine these two frameworks, we treat granules as macroscopic transport flow rather than solid boundaries for the fluid. This bidirectional coupling allows our model to accommodate a range of interphase forces with different discretization schemes, resulting in a more realistic simulation with fully respect to the mass conservation equation. Experimental results demonstrate the effectiveness of our method in simulating complex sand--water interactions, while maintaining volume consistency. Notably, in the dam-breaking experiment, our simulation uniquely captures the distinct physical properties of sand under varying infiltration degree within a single scenario. Our work advances the state of the art in granule--fluid simulation, offering a unified framework that bridges mesoscopic and macroscopic dynamics.

Problem

• Simulating stochastic behavior of sand particles in water
• Combining DEM and PIC for sand-water interaction
• Achieving realistic simulation with mass conservation

Innovation

• Combines DEM and PIC for sand-water simulation
• Treats granules as macroscopic transport flow
• Bidirectional coupling with mass conservation