Philipp Otte, MathCCES, RWTH Aachen

Title:
Stabilization of Lattice-Boltzmann Methods by Entropic Moment Closures

Abstract:

Over the past 25 years, the Lattice-Boltzmann Method (LBM) has risen to be a competitive player in the field of Computational Fluid Dynamics (CFD). The LBM owes its success to its simple structure and straight forward parallelization on modern-day architectures. Still, stability — especially for very large Reynold’s numbers — is an issue rendering it a problematic choice for properly simulating acoustics. In this talk, we extend the applicability of the LBM to solving the inviscid Linear Euler Equations. This is achieved by applying and extending the idea of entropic moment closures to linear collisions in the Lattice-Boltzmann framework. In contrast to most approaches for entropic collision operators, the post-collision state can be explicitly stated as linear combination of the pre-collision state avoiding the unpredictable optimization process inherent to most entropic collision operators.