How to Build the Optimal Magnet Assembly for Magnetocaloric Cooling: Structural Optimization with Isogeometric Analysis

TL;DR

This paper presents a computational approach using isogeometric analysis to optimize the design of axial rotary permanent magnet assemblies for magnetocaloric cooling, aiming for improved efficiency and environmental sustainability.

Contribution

It introduces a topology and shape optimization framework with harmonic mortaring for designing magnet assemblies, comparing different configurations for enhanced performance.

Findings

Optimized magnet assembly designs with improved magnetic flux homogenization.

Analysis of torque variations with geometric parameters.

Guidelines for magnetic flux guidance considering anisotropy effects.

Abstract

In the search for more efficient and less environmentally harmful cooling technologies, the field of magnetocalorics is considered a promising alternative. To generate cooling spans, rotating permanent magnet assemblies are used to cyclically magnetize and demagnetize magnetocaloric materials, which change their temperature under the application of a magnetic field. In this work, an axial rotary permanent magnet assembly, aimed for commercialization, is computationally designed using topology and shape optimization. This is efficiently facilitated in an isogeometric analysis framework, where harmonic mortaring is applied to couple the rotating rotor-stator system of the multipatch model. Inner, outer and co-rotating assemblies are compared and optimized designs for different magnet masses are determined. These simulations are used to homogenize the magnetic flux density in the magnetocaloric material. The resulting torque is analyzed for different geometric parameters. Additionally, the influence of anisotropy in the active magnetic regenerators is studied in order to guide the magnetic flux. Different examples are analyzed and classified to find an optimal magnet assembly for magnetocaloric cooling.