Investigation on the effect of the cooler design on the performance of onboard supercritical carbon dioxide power cycle for hypersonic vehicles

The scramjet cooling and power generation are the key demands for the hypersonic vehicle. To satisfy the cooling and electricity generation requirements of hypersonic vehicles, the onboard supercritical carbon dioxide (sCO2) power cycle is adopted in this paper. Moreover, the cooler design has a significant effect on the feasibility and overall performance of onboard sCO2 power cycle, but there is no research considering the effect of the cooler design. Accordingly, the effects of the cooler design on the overall performance of onboard sCO2 power cycles applied in hypersonic vehicles are comprehensively investigated based on the thermodynamic models. The results indicated that the optimum cooler designs are suggested to adopt a small channel diameter and a relatively large channel number for minimizing the cooler mass and fuel consumption for cooling sCO2 and maximizing the system thermal efficiency. Moreover, the cold channel diameter is designed to be smaller than the hot channel diameter. The cold channel number is required to be larger than the hot channel number. The total flow area of cold channel is smaller than that of hot channel. The geometric parameters of cooler hot channel could be designed based on the Re ranging from 15,000 to 34,000.