Performance Analyses of Magnetoresistive Heat Switch for Cryogenic Temperature Applications – Numerical Study
Dr. Bukke Kiran Naik
ME-215 (Conference Room)
Date & Time
22 Sep 2023 10:45 AM
The thermal conductivity of the heat switch plays a vital role in deciding the thermal performance. Thermal conductivity depends on several factors, such as temperature, magnetic field, and cross-sectional area. Thermal conductivity decreases with an increase in a magnetic field. Magneto-resistive behaviour is particularly for magnetocaloric materials such as tungsten, gallium, cadmium, and gallium, etc., which are switching elements. In the present study, the magnetoresistive behaviour of tungsten is analysed by inducing a magnetic field and heat transfer physics in COMSOL. Transient analysis is selected in the study. The magnetic field increases linearly with time and follows the expression of 0.09×t. The maximum magnetic field induced is approximately 2.75 T at 30 seconds. It is observed that magnetoresistance rises with an increase in a magnetic field. However, in the OFF state, due to magnetoresistive behaviour thermal gradient is formed over MRHS. Due to the temperature difference, thermal conductivity is not constant throughout the tungsten. The maximum temperature difference between the upper and lower flange of MRHS in the OFF state is 0.11 K. However, in the ON state temperature difference between the upper and lower flange is approximately 0. It is evident from the analysis that thermal conductivity will not be constant throughout MRHS in the OFF state. Hence, the simulation should also follow experimental testing to determine the exact thermal conductivity results.