Thermodynamic Step Segmentation in Lattice Boltzmann Method

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Solution Overview

Problem

Current computational fluid dynamics methods, such as those using the Navier-Stokes equations, face challenges in efficiently simulating high Mach and high temperature fluid flows due to limitations in temperature coupling and stability, particularly in the Lattice Boltzmann Method (LBM), which restricts its applicability to low temperature and low Mach number applications.

Innovation Solution

Introducing a thermodynamic step that is separate and independent from the particle collision step in the LBM, allowing for temperature coupling during the advection process, which modifies the distribution function to include temperature variations and maintains stability across a wide range of temperatures and Mach numbers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If temperature coupling is integrated into the particle collision step in LBM, then the method can simulate thermal flows, but the stability and accuracy deteriorate at high temperatures and high Mach numbers

Engineering Contradiction:
Improvetemperature range applicabilityVSAvoidsimulation stability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent segments the temperature coupling from the particle collision step and places it in the advection step. The distribution function evolution is divided into separate collision and advection processes, with temperature effects applied during advection rather than collision. This segmentation resolves the contradiction by allowing thermal effects to be incorporated without compromising collision-based stability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an intermediary thermodynamic step that mediates between the particle collision process and the final distribution function. This intermediate step applies temperature coupling through a correction term that bridges the isothermal collision process and the thermal advection process, enabling high-temperature simulation stability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If traditional temperature coupling methods are used in LBM, then the implementation is simple, but the method is restricted to low temperature and low Mach number applications

Engineering Contradiction:
Improveimplementation simplicityVSAvoidMach number range
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent makes the temperature coupling dynamic by applying it during the advection step where velocity and temperature variations are naturally handled. The thermodynamic correction term adapts to local flow conditions during advection, enabling the method to handle varying Mach numbers and temperatures while maintaining implementation feasibility through systematic modification of the standard LBM algorithm.

Inventive Principle:
Principle #15Dynamics

3Temperature

If the thermodynamic step is coupled with the particle collision step, then temperature effects are included, but the isotropic nature of the solver is compromised

Engineering Contradiction:
Improvetemperature couplingVSAvoidisotropic property
Core Design Contradiction:
TemperatureVSStability of the object's composition

Solution Approach 1:

By segmenting the thermodynamic step from the collision process and placing it in the advection step, the patent preserves the isotropic collision operator while introducing temperature effects through the advection correction. The collision step remains purely isotropic, and the anisotropic temperature effects are applied separately during advection, resolving the contradiction between temperature coupling and isotropy preservation.

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 enables the LBM to simulate high Mach and high temperature range applications with improved stability and accuracy, maintaining the isotropic nature of the solver and ensuring mass, momentum, and energy conservation, while avoiding the limitations of traditional temperature coupling methods.

Implementation Method 1

simulating an advection of the portion of the particles to the other location in the volume of fluid at a time t+Δt

Methodology Applied
Scientific EffectAdvection: Advection

Implementation Method 2

transport of particles in a volume of fluid, with the transport causing collision among the particles

Methodology Applied
Scientific EffectParticle collision:

Implementation Method 3

ensuring mass, momentum, and energy conservation

Methodology Applied
Scientific EffectEnergy conservation:

Implementation Method 4

ensuring mass, momentum, and energy conservation

Methodology Applied
Scientific EffectMomentum conservation: Conservation of Momentum

Data Source

PatentUS10762252B2Temperature coupling algorithm for hybrid thermal lattice boltzmann method
Publication Date: 2020.09.01 DASSAULT SYSTEMS AMERICAS CORP
  • US10762252B2 patent drawing
  • US10762252B2 patent drawing
  • US10762252B2 patent drawing

AI summary

A method includes simulating, in a lattice velocity set, transport of particles in a volume of fluid, with the transport causing collision among the particles; and generating a distribution function for transport of the particles, wherein the distribution function comprises a thermodynamic step and a particle collision step, and wherein the thermodynamic step is substantially independent of and separate from the particle collision step.