Hermite regularization of the lattice Boltzmann method for open source computational aeroacoustics
F Brogi1, O Malaspinas2, B Chopard2
1Department of Earth Sciences, University of Geneva, Rue des Maraîchers 13, CH-1205 Geneva, Switzerland.
The Journal of the Acoustical Society of America
|November 3, 2017
Summary
A new regularized lattice Boltzmann method (LBM) improves accuracy and stability for aeroacoustic simulations. This open-source approach enhances computational fluid dynamics without significant algorithmic changes.
Area of Science:
- Computational fluid dynamics
- Aeroacoustics
- Numerical methods
Background:
- The lattice Boltzmann method (LBM) is a powerful tool for aeroacoustic computations.
- Existing LBM solutions face accuracy and stability issues at low Mach numbers.
- Many proposed solutions are computationally expensive or lack accessibility due to proprietary software.
Purpose of the Study:
- To introduce an original regularized collision operator for LBM.
- To enhance the accuracy and stability of LBM for aeroacoustic applications.
- To provide an open-source, accessible LBM framework.
Main Methods:
- Developed a regularized collision operator based on Hermite polynomial expansion.
- Integrated the regularized LBM with non-reflective boundary conditions and multi-level grid strategies.
- Implemented the framework using the open-source library 'palabos'.
Main Results:
- The regularized LBM significantly improved accuracy and stability.
- The method showed excellent agreement with experimental and numerical data.
- Validated on benchmarks: laminar flow past a 2D cylinder and a 3D turbulent jet.
Conclusions:
- The proposed regularized LBM offers a stable and accurate solution for aeroacoustics.
- The open-source implementation promotes wider community adoption.
- This method retains LBM's simplicity while overcoming key limitations.
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