Eventos Anais de eventos
COBEM 2017
24th ABCM International Congress of Mechanical Engineering
Experimental Validation of an AMR Model for Magnetic Field - Fluid Flow Synchronization Analysis
Submission Author:
Alan Nakashima , SC
Co-Authors:
Sergio Luiz Dutra, Paulo Vinicius Trevizoli, Jader Riso Barbosa Jr., Alan Nakashima
Presenter: Alan Nakashima
doi://10.26678/ABCM.COBEM2017.COB17-1079
Abstract
Idealized active magnetic regenerators (AMR) are based on the thermo-magnetic Brayton cycle, which consists of two processes of adiabatic magnetic field change (magnetization and demagnetization) and two of isofield heat transfer between the solid refrigerant and the fluid thermal agent (hot and cold blows). In real systems, however, the magnetization and demagnetization steps in general occur simultaneously with the cold and hot blows. As a result, the synchronization between the magnetic field change and fluid flow processes play a vital role in the AMR behavior. Nevertheless, there is a dearth of experimental and numerical validation data on the magnetic field and fluid flow synchronization in the open literature. The objective of the present paper is to experimentally validate results of thermal performance of an AMR mathematical model subjected to different fluid flow waveforms and a fixed magnetic field variation. The experimental apparatus consists of a nested Halbach cylinder inside of which the regenerative matrix is assembled. The fluid flow is supplied by a gear pump - rotary valve system designed to perform nearly trapezoidal waveforms with different flow periods. Numerical modeling of the governing equations was performed by a Finite Volume Method routine. In this paper, four different flow profiles were experimentally evaluated and validation of model predictions was appropriately performed. The inclusion of mass unbalance further improved model solutions.
Keywords
magnetic refrigeration, active magnetic regenerator, Magnetic Field - Fluid Flow Synchronization
