Mechanics-based solution verification for porous media models

TL;DR

This paper introduces a mechanics-based framework with mathematical theorems for verifying the accuracy of porous media flow simulations, applicable across various numerical methods and capable of identifying errors and pollution in solutions.

Contribution

It develops robust a posteriori error estimation theorems based on mechanical principles for Darcy and Darcy-Brinkman models, independent of numerical methods.

Findings

Theorems confirm minimum mechanical power and dissipation characterize correct solutions.

Numerical examples demonstrate error detection capabilities of the proposed theorems.

Framework applicable to multiple numerical methods for solution verification.

Abstract

This paper presents a new approach to verify accuracy of computational simulations. We develop mathematical theorems which can serve as robust a posteriori error estimation techniques to identify numerical pollution, check the performance of adaptive meshes, and verify numerical solutions. We demonstrate performance of this methodology on problems from flow thorough porous media. However, one can extend it to other models. We construct mathematical properties such that the solutions to Darcy and Darcy-Brinkman equations satisfy them. The mathematical properties include the total minimum mechanical power, minimum dissipation theorem, reciprocal relation, and maximum principle for the vorticity. All the developed theorems have firm mechanical bases and are independent of numerical methods. So, these can be utilized for solution verification of finite element, finite volume, finite difference, lattice Boltzmann methods and so forth. In particular, we show that, for a given set of boundary conditions, Darcy velocity has the minimum total mechanical power of all the kinematically admissible vector fields. We also show that a similar result holds for Darcy-Brinkman velocity. We then show for a conservative body force, the Darcy and Darcy-Brinkman velocities have the minimum total dissipation among their respective kinematically admissible vector fields. Using numerical examples, we show that the minimum dissipation and total mechanical power theorems can be utilized to identify pollution errors in numerical solutions. The solutions to Darcy and Darcy-Brinkman equations are shown to satisfy a reciprocal relation, which has the potential to identify errors in the numerical implementation of boundary conditions.