Real-Time Multi-Phase Fluid Granular Simulation via Operator Splitting

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Solution Overview

Problem

Computer simulation of flow dynamics for multi-phase mixtures of fluids and granular substances, such as water and sand, requires complex modeling and significant computational resources, making real-time simulation challenging in resource-limited environments like video games and virtual reality applications.

Innovation Solution

A real-time simulation method is developed using a shallow-water assumption with depth-integrated governing equations and operator splitting, allowing for asynchronous updates of fluid and granular phases, which reduces computational complexity and achieves efficient time integration, enabling real-time frame rates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If complex modeling is used for multi-phase fluid and granular substance simulation, then simulation fidelity is improved, but computational resource requirements increase

Engineering Contradiction:
Improvesimulation fidelityVSAvoidcomputational resource requirements
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The simulation domain is segmented into multiple horizontal layers, with each layer representing a distinct phase (fluid, mixed, granular). This segmentation allows the complex multi-phase system to be decomposed into simpler sub-problems that can be solved independently and efficiently, reducing overall computational complexity while maintaining simulation fidelity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent extracts and applies the shallow-water assumption to remove vertical velocity components from the simulation. By taking out the negligible vertical motion from the governing equations, the model reduces computational complexity significantly while preserving the essential horizontal flow dynamics of the multi-phase system.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If complex modeling with multiple phases is used, then simulation realism is improved, but device complexity increases

Engineering Contradiction:
Improvesimulation realismVSAvoidmodeling complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The multi-phase system is segmented into distinct horizontal layers (fluid phase, mixed phase, granular phase), where each layer is modeled with appropriate simplified physics. This segmentation maintains simulation realism by capturing phase interactions while reducing modeling complexity through localized simplifications in each layer.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different physical models and assumptions are applied to different phases locally. The shallow-water assumption is applied to the fluid phase, while the granular phase uses appropriate rheological models. This local quality approach allows each phase to be modeled with the most appropriate level of complexity, improving overall realism without uniformly increasing device complexity.

Inventive Principle:
Principle #3Local quality

3Measurement precision

If detailed time integration is performed for real-time simulation, then simulation accuracy is improved, but computation time increases

Engineering Contradiction:
Improvesimulation accuracyVSAvoidcomputation time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent extracts vertical velocity components from the time integration process based on the shallow-water assumption. By removing the negligible vertical motion from the governing equations, the time integration requires fewer computational steps while maintaining accuracy for the dominant horizontal flow dynamics, thus reducing computation time.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The time integration is segmented into separate updates for different phases and operators. The fluid phase and granular phase can be updated asynchronously with different time steps, and operators are split into advection, diffusion, and source terms that can be computed independently. This segmentation allows efficient parallel computation while maintaining simulation accuracy.

Inventive Principle:
Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach allows for realistic and efficient simulation of flow dynamics in resource-constrained environments, achieving a balance between simulation fidelity and performance for immersive interactive applications.

Implementation Method 1

The physical model is further based on a shallow-water assumption such that vertical velocities in the water-sand system is considered negligible

Methodology Applied
Scientific EffectShallow-water assumption:

Implementation Method 2

The dynamics of each of the multiple phases and the water-sand mixture may be tracked in each of the plurality of horizontal cells using separate but coupled physical models for the water and sand based on mass conservation of water and sand from cell to cell

Methodology Applied
Scientific EffectMass conservation: Conservation of Momentum

Implementation Method 3

The physical model includes depth integrated governing equations that are capable of modeling an elastoplastic behavior of wet sand, as well as sand-water flow and mixing phenomena such as mass conservation, friction, diffusion, saturation, and momentum exchange

Methodology Applied
Scientific EffectMomentum exchange: Conservation of Momentum

Implementation Method 4

In performing time-evolution dynamics of the water-sand system in each of a sequence of time steps, a splitting of the various operators is adopted, providing a stable and computation efficient time integration in real-time

Methodology Applied
Scientific EffectOperator splitting:

Implementation Method 5

The physical model includes depth integrated governing equations that are capable of modeling an elastoplastic behavior of wet sand, as well as sand-water flow and mixing phenomena such as mass conservation, friction, diffusion, saturation, and momentum exchange

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 6

The physical model includes depth integrated governing equations that are capable of modeling an elastoplastic behavior of wet sand, as well as sand-water flow and mixing phenomena such as mass conservation, friction, diffusion, saturation, and momentum exchange

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 7

The dynamics of each of the multiple phases and the water-sand mixture may be tracked in each of the plurality of horizontal cells using separate but coupled physical models for the water and sand based on mass conservation of water and sand from cell to cell, and driven by various intra-cell and inter-cell forces between the various phases as well as external forces such gravity and friction from the terrain

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentUS20240338503A1Real-Time Height Field Generation of a Multi-Phase Fluid and Granular Substance Mixture
Publication Date: 2024.10.10 TENCENT AMERICA LLC
  • US20240338503A1 patent drawing
  • US20240338503A1 patent drawing
  • US20240338503A1 patent drawing

AI summary

An example real-time simulation framework for a fluid and granular substance mixture is disclosed. Such a framework may be based on modeling height fields and horizontal velocities of different material phases, which in the context of a water-sand system, may include sand, water, and mixed water. The framework achieves a trade-off between simulation fidelity and performance, providing real-time computation for interactive applications. The example framework formulates the external frictional force and elastoplastic internal force of sand based on horizontal grid and further handles the water/sand coupling via diffusion and momentum exchange. The time updates for the simulation is efficiently performed using a semi-implicit operator splitting discretization scheme and an asynchronous scheme for the fluid and the granular substance.