Transpiration cooling of a nose cone by various foreign gases
Transpiration cooling of a nose cone by various foreign gases
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各种外来气体对鼻锥的蒸发冷却
DOI：
10.1016/j.ijheatmasstransfer.2010.07.019
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发表时间：
2010-11-01
影响因子：
5.2
通讯作者：
Sun, Ji-Guo
中科院分区：
文献类型：
--
作者：
Liu, Yuan-Qing;Jiang, Pei-Xue;Sun, Ji-Guo
对用于头锥热防护的发汗冷却机理进行了实验研究和数值模拟。研究了空气、氮气、氩气、二氧化碳和氦气的注入速率、模型几何形状、入口温度和主流雷诺数等因素的影响。实验使用的是T-infinity = 375 K和425 K，Re-infinity = 4630- 10，000的热气风洞。实验结果表明，即使是少量的冷却剂注入急剧减少从热气体的传热与冷却效率的增加与喷射率的增加，虽然增加变得更小的气体喷射率进一步增加。对于目前实验研究中使用的所有冷却剂，头锥模型发汗表面上的温度和冷却效率分布沿着表现出相似的趋势。由于冷却剂质量流量的不均匀分布和金属底板的热传导，温度从驻点向下游区域先降低后升高，而冷却效率的变化则相反。局部冷却效率和热容量被发现取决于冷却剂的热物理性质。采用RNG κ-ε湍流模型对主流流动进行了二维数值模拟，采用Darcy-Brinkman-Forchheimer动量方程和热平衡模型对多孔区进行了二维数值模拟，模拟结果与实验结果吻合较好。(C)2010爱思唯尔有限公司版权所有。
The transpiration cooling mechanisms used for thermal protection of a nose cone was investigated experimentally and numerically for various cooling gases. The effects of injection rates, model geometry, inlet temperature and Reynolds number of the main stream were studied for air, nitrogen, argon, carbon dioxide and helium. The experiments used a hot gas wind tunnel with T-infinity = 375 K and 425 K and Re-infinity = 4630-10,000. The experimental results indicated that even a small amount of coolant injection drastically reduced the heat transfer from the hot gases with the cooling effectiveness increasing with increasing injection rate, although the increases became smaller as the gas injection rate was further increased. The temperature and cooling effectiveness distribution along the transpiration surface of the nose cone model exhibited similar tendencies for all the coolants employed in present experimental research. The temperature decreased from the stagnation point towards the downstream region, then increased because of the non-uniform mass flow distribution of the coolant and thermal conduction from the metal backplane, whereas the cooling effectiveness variation was the reverse. The local cooling effectivenesses and thermal capacities were found to depend on the coolant thermophysical properties. Two-dimensional numerical simulations using the RNG kappa-epsilon turbulence model for the main stream flow and the Darcy-Brinkman-Forchheimer momentum equations and thermal equilibrium model for the porous zone compared well with the general features in the experiments. (C) 2010 Elsevier Ltd. All rights reserved.