Design evaluation of an immersion heater using a fluid with low Prandtl number based on computation fluid dynamics analysis

The application of thermal management systems using liquid metal has been explored for aircraft converters and insulated-gate bipolar transistors of hybrid electric vehicles. Galinstan, a novel coolant used in thermal management systems, exhibits high thermal conductivity, low Prandtl number, and high boiling point, which enables its application in high-temperature environments of single-phase systems. In this study, we analyzed the heat transfer performance of Galinstan flowing through an immersion heater using computational fluid dynamics. The calculation was performed under different conditions with varying numbers of baffles, mass flow rates, and values of constant heat flux. The results provided the temperature, pressure drop, turbulence intensity, and streamlining of Galinstan. Based on the comparison of the heat transfer performance at different flow conditions, we determined the most suitable flow conditions and optimal heater design for maximizing the heat transfer performance.