The paper discusses a reuse of matrix factorization as a building block in the Augmented Lagrangian (AL) and modified AL preconditioners for non-symmetric saddle point linear algebraic systems. The strategy is applied to solve two-dimensional incompressible fluid problems with efficiency rates independent of the Reynolds number. The solver is then tested to simulate motion of a surface fluid, an example of a 2D flow motivated by an interest in lateral fluidity of inextensible viscous membranes. Numerical examples include the Kelvin--Helmholtz instability problem posed on the sphere and on the torus. Some new eigenvalue estimates for the AL preconditioner are derived.
@article{arxiv.2012.10073,
title = {Recycling augmented Lagrangian preconditioner in an incompressible fluid solver},
author = {Maxim Olshanskii and Alexander Zhiliakov},
journal= {arXiv preprint arXiv:2012.10073},
year = {2022}
}