Enhancing Thermal Performance of Active Magnetic Regenerator with Water-Based Nanofluid: A Simulation Study

Numerical modelling was carried out to examine how dispersing copper-oxide (CuO) nanoparticles in water alters the thermal performance of active magnetic regenerator (AMR) that employs gadolinium (magnetocaloric material) as parallel plates. A two-dimensional, time-dependent COMSOL Multiphysics model simulated two working-fluid cases—pure water (0 vol %) and a 1 vol % CuO–water nanofluid—while keeping the Reynolds number and applied magnetic field identical. Thermophysical properties were obtained from empirically derived correlations in Engineering Equation Solver, reducing computational overhead. Results show that the CuO suspension widens the attainable temperature span across the AMR by roughly 0.8 K and boosts the cycle-averaged coefficient of performance (COP) by about 5 % compared with the baseline water case. The combination of an enhanced working fluid and high-conductivity copper end exchangers promotes more efficient heat exchange between the gadolinium plates and the fluid, thereby improving both temperature span and efficiency. These findings underscore the value of thermally upgraded coolants in magnetic refrigeration and demonstrate a practical simulation framework for optimizing future AMR designs.