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Lattice Boltzmann model for exterior flows with an annealing preconditioning method
1Max-Planck Institute for Marine Microbiology, 28359 Bremen, Germany.
Summary
We developed an efficient lattice Boltzmann method for low Reynolds number flows. This technique significantly improves convergence rates and allows for larger system sizes in simulations.
Area of Science:
- Computational Fluid Dynamics
- Numerical Methods
- Fluid Mechanics
Background:
- Lattice Boltzmann methods are effective for fluid flow simulations.
- Solving exterior flows at low Reynolds numbers presents computational challenges.
- Existing preconditioning techniques have limitations in efficiency and scalability.
Purpose of the Study:
- To propose a novel, highly efficient, and stable lattice Boltzmann method.
- To enhance the treatment of low Reynolds number exterior flows.
- To improve convergence rates and system size capacity in simulations.
Main Methods:
- Implementation of a space- and time-dependent preconditioning parameter (gamma).
- Utilizing a nested mesh-refined domain for adaptive grid resolution.
- Stepwise annealing of the preconditioning parameter K from a large to a small value.
Main Results:
- Achieved convergence rates more than one order of magnitude faster.
- Enabled the treatment of system sizes several orders of magnitude larger.
- Demonstrated enhanced stability and efficiency compared to uniform grid methods.
Conclusions:
- The proposed method offers significant improvements for low Reynolds number exterior flow simulations.
- Adaptive preconditioning in nested grids is a viable strategy for computational efficiency.
- This approach broadens the applicability of lattice Boltzmann methods to larger and more complex problems.
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