Frequency correlated heat transfer characteristics of parallel plate active magnetocaloric regenerator

This paper investigates the heat transfer characteristics of oscillating flow in active magnetocaloric regenerator (AMR) by numerical simulation. We show that the operating frequency plays an important role to the heat transfer coefficient of the regenerator other than the Reynolds number and the Prandtl number. Moreover, to reveal the mechanism of the frequency correlated heat transfer characteristics, a modified synergy number Fci is proposed based on the field synergy principle. To quantitatively describe the influence of operating frequency, the oscillating Reynolds number is introduced. This paper compares the heat transfer coefficient calculated by three different methods: CFD simulation, correlations with the oscillating Reynolds number and correlations with the conventional Reynolds number. Based on the results of comparison, this paper qualitatively presents a frequency correlated heat transfer correlation for different operating frequency. In addition, a perforated parallel plate matrix regenerator is proposed to improve the heat transfer performance of the AMR.