Preconditioned Navier-Stokes schemes from the generalised lattice Boltzmann equation

摘要

Preconditioning of Navier-Stokes equations is a widely used technique to speed up Computational Fluid Dynamics simulations of steady flows. In this work a systematic study is performed of time-derivative preconditioners of Navier-Stokes equations that can be derived from the generalised lattice Boltzmann equation. In this way, lattice Boltzmann models equivalent to preconditioned Navier-Stokes systems are constructed, and it becomes possible to take advantage of the knowledge generated in this field to improve the convergence to steady state of lattice-Boltzmann flow-calculations. Two different preconditioners are obtained, which arc analysed according to their condition numbers and compared with typical Navier-Stokes preconditioners.