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The active regenerative cooling technology faces the bottleneck problem of insufficient heat transfer capacity when the scramjet flies at a higher Mach number. It is proposed to strengthen the heat transfer performance of the regenerative cooling channel with airfoil-fins. To verify the enhanced heat transfer effect of the airfoil-fin channel in principle, an experimental test platform for flow and heat transfer of ambient air in NACA0021 symmetrical airfoil-fin channels and NACA4822 asymmetric airfoil-fin channels (with cross-section sizes of 50 mm × 50 mm) was built. The Nusselt number of the heated surface was obtained based on the steady-state liquid crystal technique. The results show that, the heat transfer intensities of NACA0021 symmetrical airfoil-fin channels and NACA4822 asymmetric airfoil-fin channels improve by 0.17%~17.1% and 18.4%~52.1%, respectively. Correspondingly, PECs are 1.04 and 1.24, respectively, with the volume flow of ambient air at 50 m³/h. The NACA4822 asymmetric airfoil-fin channel can enhance the heat transfer performance of the middle heating surface under the condition of a large flow rate. The flow pressure drop in the airfoil-fin channels also increases correspondingly, where the pressure drop in the NACA4822 airfoil-fin channel is the largest. The asymmetry of the airfoil-fin causes the continuous accumulation of flow turbulence intensity, resulting in a significant increase in the downstream pressure drop. The work is helpful for further research on the flow and heat transfer characteristics of supercritical fluids in airfoil-fin channels, and broadens the application temperature range of the active regenerative cooling technology for scramjets. [ABSTRACT FROM AUTHOR]

Ｎｏｎ⁃Ｈｅｒｍｉｔｉａｎ ｌｉｎｅａｒ ｅｑｕａｔｉｏｎｓ ｈａｖｅ ｅｘｔｅｎｓｉｖｅ ａｐｐｌｉｃａｔｉｏｎ ｉｎ ｓｃｉｅｎｔｉｆｉｃ ａｎｄ ｅｎｇｉｎｅｅｒｉｎｇ ｃａｌｃｕｌａｔｉｏｎｓ ａｎｄ ａｒｅ ｅｘｐｅｃｔｅｄ ｔｏ ｂｅ ｓｏｌｖｅｄ ｗｉｔｈ ｈｉｇｈ ｅｆｆｉｃｉｅｎｃｙ． Ｔｏ ａｃｃｅｌｅｒａｔｅ ｔｈｅ ｃｏｎｖｅｒｇｅｎｃｅ ｒａｔｅ ｏｆ ｏｒｉｇｉｎａｌ ａｌｇｏｒｉｔｈｍｓ， ａ ｐｒｅｃｏｎｄｉｔｉｏｎｉｎｇ ｔｅｃｈｎｉｑｕｅ ｗａｓ ｄｅｖｅｌｏｐｅｄ ａｎｄ ａｐｐｌｉｅｄ ｔｏ ｓｏｍｅ ｉｔｅｒａｔｉｖｅ ｍｅｔｈｏｄｓ ｃｈｏｓｅｎ ｔｏ ｓｏｌｖｅ ｔｈｅ ｎｏｎ⁃Ｈｅｒｍｉｔｉａｎ ｌｉｎｅａｒ ｅｑｕａｔｉｏｎｓ ａｎｄ ｃｏｍｐｌｅｘ ｌｉｎｅａｒ ｓｙｓｔｅｍｓ ｗｉｔｈ ｍｕｌｔｉｐｌｅ ｒｉｇｈｔ⁃ｈａｎｄ ｓｉｄｅｓ． Ｓｅｖｅｒａｌ ｎｕｍｅｒｉｃａｌ ｅｘｐｅｒｉｍｅｎｔｓ ｓｈｏｗ ｔｈａｔ ｔｈｅ ｐｒｅｃｏｎｄｉｔｉｏｎｅｄ ｉｔｅｒａｔｉｖｅ ｍｅｔｈｏｄｓ ａｒｅ ｓｕｐｅｒｉｏｒ ｔｏ ｔｈｅ ｏｒｉｇｉｎａｌ ｍｅｔｈｏｄｓ ｉｎ ｔｅｒｍｓ ｏｆ ｂｏｔｈ ｔｈｅ ｃｏｎｖｅｒｇｅｎｃｅ ｒａｔｅ ａｎｄ ｔｈｅ ｎｕｍｂｅｒ ｏｆ ｉｔｅｒａｔｉｏｎｓ． Ｉｎ ａｄｄｉｔｉｏｎ， ｔｈｅ ｐｒｅｃｏｎｄｉｔｉｏｎｅｄ ｇｅｎｅｒａｌｉｚｅｄ ｃｏｎｊｕｇａｔｅ Ａ⁃ ｏｒｔｈｏｇｏｎａｌ ｒｅｓｉｄｕａｌ ｓｑｕａｒｅｄ ｍｅｔｈｏｄ （ＧＣＯＲＳ２） ｈａｓ ｂｅｔｔｅｒ ｃｏｎｖｅｒｇｅｎｔ ｂｅｈａｖｉｏｒ ａｎｄ ｓｔａｂｉｌｉｔｙ ｔｈａｎ ｏｔｈｅｒ ｐｒｅｃｏｎｄｉｔｉｏｎｅｄ ｍｅｔｈｏｄｓ． [ABSTRACT FROM AUTHOR]