Parallel efficiency of monolithic and fixed-strain solution strategies for poroelasticity problems

TL;DR

This paper compares the parallel efficiency of monolithic and fixed-strain solution strategies for poroelasticity problems, highlighting how solver performance impacts scalability in coupled systems.

Contribution

It provides an analysis of the parallel scalability of two different solution strategies for poroelasticity, challenging assumptions about splitting strategy advantages.

Findings

Splitting strategy does not always outperform monolithic in parallel scalability.

Solver performance significantly influences the efficiency of solution strategies.

Parallel scalability depends on the structure of the algebraic systems and solver efficiency.

Abstract

Poroelasticity is an example of coupled processes which are crucial for many applications including safety assessment of radioactive waste repositories. Numerical solution of poroelasticity problems discretized with finite volume -- virtual element scheme leads to systems of algebraic equations, which may be solved simultaneously or iteratively. In this work, parallel scalability of the monolithic strategy and of the fixed-strain splitting strategy is examined, which depends mostly on linear solver performance. It was expected that splitting strategy would show better scalability due to better performance of a black-box linear solver on systems with simpler structure. However, this is not always the case.