Fluid Dynamics Module

Overview

The FluidDynamics module provides a Lattice Boltzmann Method (LBM) solver for incompressible and compressible fluid flow within the OpenPhase framework. It is designed for tightly coupled phase-field and fluid simulations — including multi-phase flow, solid–fluid interaction, thermally compressible flow, and reactive flow.

The module is self-contained and interacts with the broader OpenPhase framework through the PhaseField, Velocities, BoundaryConditions, Composition, and Temperature objects.

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Physics scope

Capability	Description
Single-phase incompressible flow	Navier–Stokes via BGK-LBM (isothermal)
Multi-phase / multi-component flow	Pseudo-potential methods (Benzi, Kupershtokh)
Phase-field coupling	Diffuse-interface solid–fluid boundaries
Solid–fluid interaction	Bounce-back, drag forces, rigid body motion
Solid–solid interaction	Short-range repulsion (Standard / Wang models)
Thermally compressible flow	Low-Mach number compressible extension
Reactive flow	Coupling to species transport and heat sources

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See also: examples

In OpenPhase-main/examples/:

• Flow — single-phase incompressible flow.
• ThermalCompressibleFlow — Poiseuille / cylinder / packed-bed thermally compressible variants.
• Foam — foam-microstructure flow.
• ReactiveFlow — combustion in 0D, 1D, and 2D — see Reactive Flows.

Module components

Class	Header	Role
FlowSolverLBM	FluidDynamics/FlowSolverLBM.h	Core D3Q27 LBM solver
D3Q27	FluidDynamics/D3Q27.h	Population array and stencil weights
InteractionFluidFluid	FluidDynamics/InteractionFluidFluid.h	Fluid–fluid pseudo-potential forces
InteractionSolidFluid	FluidDynamics/InteractionSolidFluid.h	Solid–fluid coupling and rigid body dynamics
InteractionSolidSolid	FluidDynamics/InteractionSolidSolid.h	Solid particle short-range repulsion
BenziGas	FluidDynamics/BenziGas.h	Benzi pseudo-potential EOS helper
VanDerWaalsGas	FluidDynamics/VanDerWaalsGas.h	Van der Waals EOS helper

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Position in a simulation

In a typical OpenPhase simulation, the FluidDynamics module is instantiated alongside the phase-field and transport modules and called each time step after the phase-field update:

Settings, BoundaryConditions
    ↓
PhaseField (microstructure evolution)
    ↓
FlowSolverLBM::Solve()   ← FluidDynamics module
    ↓
AdvectionHR, Diffusion, Temperature, ...

The Velocities object bridges the LBM solver and advective transport: the LBM solver writes fluid velocities into it, and advection/diffusion modules read from it.

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Related publications

TODO

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Documentation pages

Page	Content
LBM Theory	Mathematical foundations
FlowSolverLBM	Main solver class
Multi-Phase Flow	Pseudo-potential models
Solid–Fluid Interaction	Bounce-back, drag, rigid bodies
Solid–Solid Interaction	Particle contact models
Thermal Compressible Flow	Low-Mach compressible extension
Reactive Flow	Coupling to combustion / chemistry
Usage & I/O	Input file, output fields, examples