Analysis and optimization of flow and heat transfer performance of active thermal protection channel for hypersonic aircraft

This paper presents a numerical simulation on the thermal-hydraulic performance of multiple parallel cooling channels to realize active thermal protection of hypersonic aircraft. The fluid velocity is set in the range of 0.5-2.5 m/s, with the corresponding Reynolds number of 4300 to 22,000, and results show that the rectangular and triangular channel have the best cooling performance on outer wall and inner wall with water as coolant, respectively. Further, "Diamond" channel is proposed to improve the cooling performance, and aviation kerosene RP-3 is used as coolant. Three inlet temperatures (243, 253 and 263 K) are applied to investigate the thermal protection performance of Diamond channel. The cooling performance of RP-3 is better than water, and total pump power of RP-3 is only 60% of water. It is found that the conspicuous symmetric longitudinal swirls generated at the leading edge effectively enhance the heat convection performance. Under the studied ranges of fluid velocity and inlet temperatures, outer and inner wall temperatures can be controlled below 700 K and 330 K, respectively. Subsequently, the preliminary parameters of the "Diamond" are investigated and optimized. Model with L = 16 mm, Yc = 3 and X = 8.8 mm has better thermal protection performance and mechanical properties.