Anthony PLAIT : "Multiphysics Modeling of Magnetocaloric Regenerators"

PhD Works of Anthony PLAIT : "

Abstract: 

The research carried out in this thesis is part of a desire to eliminate gases that strongly aggravate global warming (greenhouse effect) in refrigeration machines. Active magnetic regenerative refrigeration (AMRR), a still emerging technology, is a possible answer to this challenge. The objective of this thesis work is to propose a global multiphysics modelling of a test bench for magnetocaloric regenerators combining precision and numerical efficiency (calculation time). After a broad bibliographic study of the most recent magnetocaloric models and prototypes, a multiphysics modelling is proposed. For this purpose, three sub-models (magnetostatic, magnetocaloric and thermo-fluidic) are coupled in order to take into account all the phenomena occurring within the magnetocaloric regenerator during the AMRR cycles. Our model is then used to assess the influence of input parameters such as cycle frequency and regenerator sweep rate on the thermal performance of the system. A process of optimization by modulation of these parameters over time is proposed to significantly reduce the time required to reach the steady state of the magnetocaloric regenerator in different situations. The completion, development and validation of the magnetocaloric bench is described in detail to accurately identify and measure the magnetocaloric effect in gadolinium, and then to apply the AMRR cycles to the regenerator. The results of these experiments allow us to validate our multiphysics model with very good accuracy, paving the way for a systematic exploration of the performance of future regenerators designed in the labora

Composition of the jury :

M. Feidt Michel, Professeur émérite, LEMTA, Université de Lorraine

Mme Kedous Lebouc Afef, Directrice de recherches CNRS, G2ELAB, Université Grenoble Alpes

M. Lo Bue Martino, Chargé de recherches CNRS, SATIE, ENS Cachan

M. Espanet Christophe, Professeur des Universités, FEMTO-ST, Université de Franche-Comté

M. de Larochelambert Thierry, Professeur de Chaire Supérieure, FEMTO-ST, Université de Haute Alsace

M. Giurgea Stefan, Maître de conférences, FEMTO-ST, UTBM

M. Nika Philippe, Professeur des Universités, FEMTO-ST, Université de Franche-Comté

M. Bailly Yannick, Professeur des Universités, FEMTO-ST, Université de Franche-Comté

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