On Techniques for Barely Coupled Multiphysics

TL;DR

This paper presents a simple, loosely coupled technique for solving barely coupled multiphysics problems, demonstrated through electric motor cooling, enabling accurate and efficient simulations in emerging aerospace applications.

Contribution

It introduces a novel approach for combining codes in barely coupled multiphysics problems with flexible stopping criteria, enhancing implementation simplicity and accuracy.

Findings

Effective in evaporative cooling of electric motors

Viable for aerospace electric propulsion applications

Maintains accuracy with loose coupling approach

Abstract

A technique to combine codes to solve barely coupled multiphysics problems has been developed. Each field is advanced separately until a stop is triggered. This could be due to a preset time increment, a preset number of timesteps, a preset decrease of residuals, a preset change in unknowns, a preset change in geometry, or any other physically meaningful quantity. The technique allows for a simple implementation in coupled codes using the loose coupling approach. Examples from evaporative cooling of electric motors, a problem that has come to the forefront with the rise of electric propulsion in the aerospace sector (drones and air taxis in particular) shows the viability and accuracy of the proposed procedure.