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Updated: Jun 25, 2026
11:03
An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids
Published on: December 4, 2017
Towards a physical interpretation of the entropic lattice Boltzmann method
Orestis Malaspinas1, Michel Deville, Bastien Chopard
1Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland. orestis.malaspinas@epfl.ch
Summary
The entropic lattice Boltzmann method (ELBM) offers a unique approach to hydrodynamic simulations by incorporating a variable relaxation time. Our analysis reveals ELBM acts as a subgrid model, with viscosity corrections linked to the strain rate tensor.
Area of Science:
- Computational fluid dynamics
- Hydrodynamics
- Numerical methods
Background:
- The entropic lattice Boltzmann method (ELBM) is a variant of the lattice Boltzmann method for simulating fluid dynamics.
- The ELBM's collision term ensures a nonincreasing H function through a variable relaxation time.
- Understanding the theoretical underpinnings and practical implications of ELBM is crucial for advancing computational fluid dynamics.
Purpose of the Study:
- To analyze the entropic lattice Boltzmann method (ELBM) using the Chapman-Enskog expansion.
- To interpret the ELBM as a subgrid model in hydrodynamic simulations.
- To validate analytical findings through numerical computations.
Main Methods:
- Chapman-Enskog expansion for theoretical analysis.
- Interpretation of ELBM as a subgrid model.
- Numerical computation of relaxation time modifications.
- Two-dimensional dipole-wall interaction benchmark simulation.
Main Results:
- The ELBM can be interpreted as a subgrid model.
- Viscosity corrections in ELBM scale with the strain rate tensor.
- Numerical computations confirm the analytical findings regarding relaxation time modifications.
Conclusions:
- The entropic lattice Boltzmann method exhibits subgrid-scale modeling characteristics.
- The variable relaxation time in ELBM leads to viscosity corrections dependent on the strain rate tensor.
- Numerical validation supports the theoretical analysis of ELBM behavior.
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