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Entropic multirelaxation lattice Boltzmann models for turbulent flows.
Fabian Bösch1, Shyam S Chikatamarla1, Ilya V Karlin1
1Department of Mechanical and Process Engineering, ETH Zurich, 8092 Zurich, Switzerland.
Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics
|November 14, 2015
Summary
This study presents stable 3D lattice Boltzmann models for turbulent flows. The entropic stabilizer ensures accurate simulations, showing promise for engineering and scientific applications.
Area of Science:
- Computational physics
- Fluid dynamics
- Numerical methods
Background:
- Lattice Boltzmann methods (LBM) are powerful for simulating fluid dynamics.
- Recent advancements introduced a new class of LBM with an entropic stabilizer.
- Assessing the performance and stability of these models in 3D is crucial.
Purpose of the Study:
- To present and analyze three-dimensional realizations of a novel lattice Boltzmann model.
- To investigate the role and effectiveness of the entropic stabilizer in these models.
- To evaluate the model's performance for high-Reynolds-number and turbulent flows.
Main Methods:
- Developed three-dimensional lattice Boltzmann models with an entropic stabilizer.
- Performed simulations using both coarse- and fine-grid approaches.
- Utilized the Kida vortex flow benchmark for validation.
- Analyzed homogeneous isotropic decaying turbulence for statistical quantities.
Main Results:
- Demonstrated outstanding numerical stability and performance, independent of moment representation for high-Reynolds-number flows.
- Achieved accurate results for low-order moments and second-order grid convergence in turbulence simulations.
- Confirmed convergence to the lattice Bhatnagar-Gross-Krook model with increased resolution.
- Observed reduced compressibility effects and maintained correct energy/enstrophy dissipation due to the entropic stabilizer.
Conclusions:
- The presented 3D lattice Boltzmann models offer excellent numerical stability and efficiency.
- The entropic stabilizer is key to achieving accurate and robust simulations of turbulent flows.
- These models are promising for advanced engineering and scientific applications involving highly turbulent regimes.
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