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对超高温燃烧室发散冷却全场进行有效的数值模拟对燃烧室材料结构设计具有重要的意义。该文通过FLUENT 6.1,采用RNG k-ε湍流模型,建立了高温气体流过圆管时多孔介质壁面发散冷却的全场耦合数值计算模型。该模型计算结果与低温氦气、低温空气发散冷却实验结果基本吻合。该文研究了常温氢气对超高温燃烧室内燃气的发散冷却,结果表明,忽略对流传质边界层的影响会导致计算预测的壁面温度偏高,忽略孔隙率局部分布的不均匀性会导致冷却壁面端部出现高温计算结果,这不符合常理。在注入率为1%左右时,冷却壁面温度在400~900 K的范围内,壁面局部热流密度降至200 kW/m2左右,可以满足航天器燃烧室保护壁面的需要。
Effective numerical simulation of the divergent cooling of the ultra-high temperature combustion chamber is of great significance to the design of the material structure of the combustion chamber. In this paper, a turbulence model of RNG k-ε is adopted in FLUENT 6.1 to establish a numerical model for the coupled field coupling of porous media wall cooling with high temperature gas flowing through a circular tube. The results of the model are in good agreement with experimental results of low-temperature helium and low-temperature air divergence cooling. In this paper, the divergent cooling of gas at room temperature in the ultra-high temperature combustion chamber is studied. The results show that neglecting the influence of the convective mass transfer boundary layer leads to high predicted wall temperature. Ignoring the non-uniform local porosity distribution leads to the cooling wall It is not common sense to have high-temperature calculations at the ends. When the injection rate is about 1%, the cooling wall temperature is in the range of 400 ~ 900 K, and the local heat flux density in the wall is reduced to about 200 kW / m2, which can meet the needs of spacecraft combustion chamber protection wall.