The Performance Impact of Newton Iterations per Solver Call in Partitioned Fluid-Structure Interaction

TL;DR

This paper investigates how the number of Newton iterations within nonlinear solvers affects the overall efficiency of partitioned fluid-structure interaction schemes, emphasizing the importance of optimizing these internal iterations.

Contribution

It introduces a method to determine the optimal number of Newton steps per coupling iteration to improve computational efficiency in fluid-structure interaction simulations.

Findings

Optimal Newton iteration count improves solver efficiency

Highlighting the significance of internal Newton loops in performance assessment

Guidelines for balancing Newton and coupling iterations

Abstract

The cost of a partitioned fluid-structure interaction scheme is typically assessed by the number of coupling iterations required per time step, while ignoring the Newton loops within the nonlinear sub-solvers. In this work, we discuss why these single-field iterations deserve more attention when evaluating the coupling's efficiency and how to find the optimal number of Newton steps per coupling iteration.