Effect of Forced Heat Convection on Heat Transfer for Bipolar MVDC Power Cables in Envisaged Wide-Body All-Electric Aircraft

Since transportation is one of the primary sources of greenhouse gas (GHG) emissions, its electrification is essential for achieving the net-zero GHG emissions target. As a part of transportation electrification, all-electric aircraft (AEA) have emerged as a viable approach to achieve net-zero emissions in aviation. Electric power systems (EPS) with high power density and low system mass are required for future wide-body AEA. Power cables, as one of the key components of the aircraft EPS, must be constructed to maximize the overall power density of the EPS. Because of the limited heat transfer by convection at cruising altitudes of wide-body AEA, the design of power cables faces significant thermal challenges. These difficulties are worsened using bipolar MVDC EPSs, which are generally composed of two power cables, negative and positive poles, adjacent to one another. Heat transfers that occur through convection and radiation are influenced by the cable's surface area. To offset the decrease in convective heat transfer brought on by the low air pressure, one method is to apply forced heat convection. Increasing the velocity of forced air in a cable duct, either the surface temperature of the cable can be reduced, or the core diameter can be reduced along with the cable weight maintaining the same temperature obtained from natural heat convection. This paper examines the impact of forced heat convection on a conventional cylindrical bipolar cable system. The cable system is equipped with our novel designed ARC-SCT-MMEI insulation system delineated in the paper, and its performance is compared to that of natural heat convection.