Multi-field Coupled Lattice Boltzmann Model for Heat and Mass Transfer
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Solution Overview
Problem
Current multi-velocity and multi-distribution function models for heat and mass transfer flow simulation using the Lattice Boltzmann method face limitations such as poor numerical stability and inability to adjust the Prandtl number, and are mainly suited for low Mach number and small temperature/concentration gradient simulations, lacking a comprehensive model for reservoir heat and mass transfer flow.
Innovation Solution
A multi-field coupled Lattice Boltzmann simulation method combining a total energy distribution model with a passive scalar model using an introduced set force term to achieve bidirectional coupling of flow, temperature, and concentration fields, allowing for the simulation of flow velocity, temperature, and pollutant concentration distribution in a target water body.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the multi-velocity model is used to simulate heat and mass transfer flow, then the temperature macro-evolution equation can be restored, but the Prandtl number cannot be adjusted and numerical stability deteriorates
Solution Approach 1:
The model segments the simulation into separate distribution functions for flow field (f), temperature field (g), and concentration field (h), allowing independent optimization of each field's numerical stability while maintaining their coupling through the force term B
Solution Approach 2:
The model changes the parameter representation by using separate relaxation times (τf, τg, τh) for each distribution function, enabling independent adjustment of numerical stability parameters and Prandtl number without compromising overall simulation stability
2Adaptability or versatility
If the multi-distribution function model is used to simulate heat and mass transfer flow, then the Prandtl number becomes adjustable and numerical stability improves, but the flow equation of state becomes independent of temperature and concentration
Solution Approach 1:
The model introduces a feedback mechanism where temperature difference and concentration difference generate body force B = -g[βT(T-T0) + βC(C-C0)], which feeds back to the flow field to drive convective motion, thereby restoring the coupling between fields that was missing in previous models
Solution Approach 2:
The body force term B acts as an intermediary that couples the temperature and concentration fields to the flow field, translating thermal and concentration gradients into mechanical forces that drive fluid motion and restore the complete physics coupling
3Adaptability or versatility
If existing coupling models are used, then partial field coupling can be achieved, but comprehensive bidirectional coupling of flow, temperature, and concentration fields has not been realized
Solution Approach 1:
The model merges the flow field, temperature field, and concentration field simulations into a unified multi-field coupled LB model with bidirectional coupling, where all three fields interact through the force term B while maintaining their own distribution functions and evolution equations
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 accurate three-dimensional spatial distribution mapping of flow, temperature, and concentration fields, improving simulation accuracy for water temperature and quality, and addressing the limitations of existing models by enabling bidirectional coupling and adjustable Prandtl number.
Implementation Method 1
a multi-field coupled Lattice Boltzmann (LB) simulation method for heat and mass transfer flow
Implementation Method 2
the uneven distribution of temperature and concentration will make the density difference of the water body and then form the bulk force to drive the water flow
Implementation Method 3
the convective effect of water flow affects the distribution of temperature and concentration
Data Source
AI summary
The invention discloses a multi-field coupled Lattice Boltzmann (LB) simulation method and system designed for heat and mass transfer flow, along with a storage medium. Initial parameters of a target water body are acquired and imported into a pre-set multi-field coupled LB model for heat and mass transfer flow simulation. This process yields flow velocity distribution, temperature distribution, and pollutant concentration distribution information, facilitating the accurate depiction of a three-dimensional spatial distribution map of the flow field, temperature field, and concentration field of the target water body. Through the integration of a total energy distribution LB model and a passive scalar model via a force term, bidirectional coupling of the flow field, temperature field, and concentration field is achieved. This establishes a multi-field coupled LB model capable of accurately simulating water temperature and quality, surpassing conventional methods in water temperature simulation accuracy.