Two-Dimensional multiphysics modeling of a magnetocaloric device and parametric study.

The modeling of the multiphysics phenomena that occur inside the active magnetocaloric regenerators requires the coupling of magnetostatic, magnetocaloric and thermo-fluidic models. The main objective of the contribution presented is to combine the very low resolution time of the multiphysics model with a good accuracy. In this context, a magnetostatic semi-analytical modelling has been developed in order to calculate the values of the magnetic field and the magnetic flux density at each point of the magnetocaloric regenerator volume. The magnetocaloric model calculates the magnetization and the magnetocaloric power density. A thermo-fluidic model computes the new temperatures in the fluid and inside the active magnetocaloric material. Indeed, the multiphysics model needs much less computation time than FEM and ensures a compatibility with an optimization process. The dependence of fluid displacement ratio and functioning frequency is assessed in order to determine the optimal working point for an imposed set of external conditions.

有源磁热蓄热器（Active Magnetocaloric Regenerator）内部多物理场现象的建模，需将静磁学、磁热学与热流体学模型进行耦合。本文所呈现研究的核心目标，是将该多物理场模型极短的求解时长与优异的计算精度相结合。在此背景下，本工作开发了一种静磁学半解析建模方法，用于计算磁热蓄热器体积内各点的磁场与磁通密度。磁热学模型用于求解磁化强度与磁热功率密度；热流体学模型则可计算流体与有源磁热材料内部的更新温度。实际上，该多物理场模型的计算耗时远低于有限元法（Finite Element Method, FEM），且可兼容优化流程。本研究还评估了流体位移比与工作频率的依赖关系，以在给定的外部工况集合下确定最优工作点。