A novel block non-symmetric preconditioner for mixed-hybrid finite-element-based Darcy flow simulations

In this work, we propose a novel block preconditioner, labeled Explicit Decoupling Factor Approximation (EDFA), to accelerate the convergence of Krylov subspace solvers used address sequence non-symmetric systems linear equations originating from flow simulations in porous media. The model is discretized blending Mixed hybrid finite element method for Darcy's equation with Finite volume scheme mass conservation. EDFA preconditioner characterized by two features: exploitation system matrix decoupling factors recast Schur complement and their inexact fully-parallel computation means restriction operators. We introduce adaptive techniques aimed at building operators according properties hand. proposed has been tested through extensive experimentation on both synthetic real-case applications, pointing out its robustness computational efficiency.