NekLBM

A High-Order Spectral Element Lattice Boltzmann Solver

NekLBM is a high-order Spectral Element Lattice Boltzmann Method (SELBM) solver built upon the scalable Nek5000 framework. By leveraging Nek5000’s robust mesh generation, high-performance I/O, and advanced MPI distribution systems, NekLBM provides a powerful platform for simulating complex fluid dynamics.

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🚀 Key Capabilities

NekLBM is engineered for high-fidelity simulations across multiple regimes:

• Single-phase flows
• Multi-phase flows
• Multi-species fluid dynamics

🏗️ Framework Integration

NekLBM is fully integrated with the Nek5000 ecosystem, inheriting its industrial-grade capabilities for High-Performance Computing (HPC):

• Mesh Geometry: Utilizes native spectral element mesh information for complex geometries.
• I/O System: High-efficiency data handling for large-scale simulations.
• Distributed Systems: Optimized for massive parallelism via MPI.

📚 Citation

If you use NekLBM in your research, please cite our latest work:

[1] Zhao, C., Patel, S.S., Lin, H.L., Min, M. and Lee, T., 2026. A flux bounce-back scheme for the filtered Spectral Element Lattice Boltzmann Method. Computers & Fluids, p.106987. https://doi.org/10.1016/j.compfluid.2025.106987

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🛠️ Installation

NekLBM is built on top of the Nek5000 framework. Before proceeding, ensure you have a working environment for the core solver.

1. Prerequisites (Nek5000)

Follow the official Nek5000 Quickstart Guide to install the base framework, compilers, and dependencies: 👉 Nek5000 Installation & Quickstart

2. Core Modification

To enable the LBM driver, you must replace the default drive1.f file within the Nek5000 source tree:

• Target Path: Nek5000/core/drive1.f
• Action: Replace this file with the drive1.f provided in the NekLBM repository.

3. Lattice & Physics Configuration

The lattice structures and simulation parameters are defined in specific header/source files. Choose the file corresponding to your simulation requirements:

Single-Phase Lattices

Dimension	Lattice Type	Parameter File
2D	D2Q9	LBMD2Q9
3D	D3Q13	LBMD3Q13
3D	D3Q15	LBMD3Q15
3D	D3Q19	LBMD3Q19
3D	D3Q27	LBMD3Q27

Multi-Phase & Multi-Species

For specialized physics, parameters are stored in the following files:

• Multi-Phase Flow:
  • 2D: LBMPHASE
  • 3D: LBMPHASE3
• Multi-Species Flow:
  • 2D: LBMDIFFUSION
  • 3D: LBMDIFFUSION3 Once the files are exchanged and parameters are set:

1. Initialize your case directory using makenek.
2. Compile as you would for a standard Nek5000 project.