A parametric and comparative study of a permanent magnet structure

Permanent magnets remain the primary source of magnetic field in magnetic refrigerators and thermomagnetic motors, generally being evaluated by the \({\Lambda }_{{\text{cool}}}\) ${\mathrm{\Lambda }}_{\text{cool}}$ parameter, which is applicable to a magnetic field source used in a magnetic refrigeration system. The main objective of this work is to perform a parametric and comparative analysis of a C-shaped and double C-shaped permanent magnet based on a common parameter to any arrangement of magnets, namely the figure of merit \({M}^{*}\) $M^{\ast }$ . The analysis was conducted through computational modeling and simulation with COMSOL Multiphysics® software. Different soft magnetic materials were used in the simulations and the best-performing material was used in the magnetic circuit of the C-shaped permanent magnet to evaluate the magnetic force acting on a set of gadolinium plates. It was observed that the soft magnetic material has a significant impact on \({M}^{*}\) $M^{\ast }$ . No significant impact on \({M}^{*}\) $M^{\ast }$ was observed regarding to the number of gaps as long as more magnetized blocks are employed in the arrangement. Consequently, a greater gap accompanied by a lower magnetic flux density has the potential to result in an increased magnetostatic force density.