Physically Based Preconditioning Techniques Applied to the First Order Particle Transport and to Fluid Transport in Porous Media

Michael Rigley
2014
Physically based preconditioning is applied to linear systems resulting from solving the first order formulation of the particle transport equation and from solving the homogenized form of the simple flow equation for porous media flows. The first order formulation of the particle transport equation is solved two ways. The first uses a least squares finite element method resulting in a symmetric positive definite linear system which is solved by a preconditioned conjugate gradient method. The
more » ... cond uses a discontinuous finite element method resulting in a non-symmetric linear system which is solved by a preconditioned biconjugate gradient stabilized method. The flow equation is solved using a mixed finite element method. Specifically four levels of improvement are applied: homogenization of the porous media domain, a projection method for the mixed finite element method which simplifies the linear system, physically based preconditioning, and implementation of the linear solver in parallel on graphic processing units. The conjugate gradient linear solver for the least squares finite element method is also applied in parallel on graphics processing units. The physically based preconditioner is shown to perform well in each case, in relation to speed-ups gained and as compared with several algebraic preconditioners.
doi:10.26076/1b20-9686 fatcat:2spa66b4gzg6jh7qthtreq7dsu