Numerical investigation of flow dynamics and cooling performance in combined porosity structures at the leading edge of a hypersonic vehicle

IF 5 2区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Heat and Mass Transfer Pub Date : 2025-04-03 DOI:10.1016/j.ijheatmasstransfer.2025.126996

Weijie Chen , Yongqing Wang , Shantung Tu , Tiange Chu , Huijuan Su , Ke Wang

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引用次数: 0

Abstract

Transpiration cooling presents significant promise for enhancing thermal protection in hypersonic vehicles. However, leading edge structures with single-homogeneous porosity (LE-SHP) frequently encounter excessive flow resistance at the stagnation point, resulting in non-uniform temperature distribution in localized regions, which adversely influences the thermal protection effectiveness. In response, a combined porosity structure (LE-GHP) based on local thermal equilibrium model was introduced in this paper. The cooling mechanism of LE-GHP at Mach 7 was analyzed using a step-by-step numerical simulation method. The effects of coolant injection rate and combined porosity distribution on coolant flow and cooling performance were investigated. Furthermore, the impact of discontinuous transpiration surfaces with varying lengths on downstream cooling performance was evaluated. The results indicate that flow resistance at the stagnation point is reduced by LE-GHP, forming a more uniform cooling gas film that significantly mitigates the thermal impact of high-enthalpy freestream on the transpiration surface. Compared to the LE-SHP, superior cooling performance with lower endothermic power under different coolant injection rates are demonstrated by LE-GHP, improving the temperature distribution uniformity of the transpiration surface by 30.56–70.79 % and increasing the average cooling efficiency of the hot surface by 11.48–13.01 %. Additionally, when the gradient porosity region ranges from 0° to 60° (θ=60°), the endothermic power of transpiration surface is reduced by up to 64.88 %, with a corresponding increase in the thermal protection effect on hot surface by up to 28.17 %. In comparison to θ=60°, the discontinuous transpiration surface with a length of 1 mm not only ensures the reliability of thermal protection material, but also improves the temperature distribution uniformity of hot surface by 18.36 %.

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蒸发冷却为增强高超音速飞行器的热保护带来了巨大希望。然而，单均质多孔结构（LE-SHP）的前缘结构经常会在停滞点遇到过大的流动阻力，导致局部区域的温度分布不均匀，从而对热保护效果产生不利影响。为此，本文介绍了一种基于局部热平衡模型的组合多孔结构（LE-GHP）。采用分步数值模拟方法分析了 LE-GHP 在马赫数为 7 时的冷却机理。研究了冷却剂注入率和组合孔隙率分布对冷却剂流动和冷却性能的影响。此外，还评估了不同长度的不连续蒸发面对下游冷却性能的影响。结果表明，LE-GHP 减少了停滞点的流动阻力，形成了更均匀的冷却气膜，大大减轻了高焓自由流对蒸腾表面的热影响。与 LE-SHP 相比，LE-GHP 在不同的冷却剂喷射速率下均表现出更优越的冷却性能和更低的内热功率，使蒸发表面的温度分布均匀性提高了 30.56-70.79 %，热表面的平均冷却效率提高了 11.48-13.01 %。此外，当梯度孔隙率区域在 0° 至 60° 之间（θ=60°）时，蒸腾面的内热功率最多可降低 64.88 %，热表面的热保护效果也相应提高 28.17 %。与 θ=60° 相比，长度为 1 毫米的不连续蒸腾面不仅确保了热保护材料的可靠性，还使热表面的温度分布均匀性提高了 18.36%。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

International Journal of Heat and Mass Transfer 工程技术-工程：机械

CiteScore

10.30

自引率

13.50%

发文量

1319

审稿时长

41 days

期刊介绍： International Journal of Heat and Mass Transfer is the vehicle for the exchange of basic ideas in heat and mass transfer between research workers and engineers throughout the world. It focuses on both analytical and experimental research, with an emphasis on contributions which increase the basic understanding of transfer processes and their application to engineering problems. Topics include: -New methods of measuring and/or correlating transport-property data -Energy engineering -Environmental applications of heat and/or mass transfer