Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
Design and assembly of a magnetic circuit with four magnetic field regions applied to a thermomagnetic motor prototype
Submission Author:
Dalila Torres , MG , Brazil
Co-Authors:
Dalila Torres, Clara Silva, Vinicius Souza de Jesus, Gustavo Costa Mendonça, Higor Caldas Rios, Hugo Cesar Coelho Michel, Carmela Maria Polito Braga, Paulo Vinicius Trevizoli, Marcelo Câmara
Presenter: Clara Silva
doi://10.26678/ABCM.COBEM2023.COB2023-0488
Abstract
Thermomagnetic motors are devices employed to convert low-grade thermal energy wastes into mechanical energy. The linear or rotary movement results from the magnetic phase variation (around the Curie temperature, T_Curie) of a magnetic material and its interaction with an external magnetic field region. Below T_Curie the material is ferromagnetic and above paramagnetic. Among the different concepts presented in the open literature, rotary prototypes are able to produce larger mechanical powers associated with a more continuous movement. The present work proposes the design, fabrication and assembly of a permanent magnet magnetic circuit (MC) which is part of a rotary thermomagnetic motor currently under construction at the Federal University of Minas Gerais. The MC concept have four high magnetic field region, with the objective of maximize the produced power. The design involved 2D and 3D simulations in COMSOL Multiphysics, Module AC/DC, to evaluate the magnetic field intensity and distribution in the magnetic gap. Important parameters were investigated, such as the magnetic gap height and the use of soft magnetic materials, towards to maximize the magnetic field intensity and stablish a more homogeneous filed volume. The final MC design is composed of NdFeB grade N42, assembled in a Halbach array, associated with ABNT 1020 steel. The steel parts were produced, considering the components measurements and the definition of the used materials and tools and, later, the MC was assembled. Along the production, conventional machining operations were employed using, mostly, the Machine Center. The employment of appropriate cutting parameters and tools allowed to achieve the specified dimensional tolerance and roughness. This enabled the proper assembly of the MC, with minimum deviations and, therefore, the experimental results for the magnetic field presented a good agreement with simulation data.
Keywords
Thermomagnetic motors, magnetic circuit, Design, Heat transfer
