Abstract

This paper numerically investigates the heat transfer characteristics of supersonic high-temperature combustion-gas jet impinging to a perpendicular flat plate. First, the numerical method is validated using an experimental case and meanwhile different turbulence models are evaluated for heat transfer prediction. Then, the effects of multi-species, nozzle-to-plate distance, and nozzle pressure ratio on wall heat transfer are studied through a series of numerical experiments. Comparison of different turbulence models indicates that the variations of turbulent viscosity across the detached normal shock wave differ among the studied three models. Furthermore, if the real multi-species of combustion-gas are mixed as a single species with the same thermal-physical properties, the pressure and heat flux distributions are identical with the results of combustion-gas. Finally, when there is no stagnation bubble in the jet flow field, the heat flux on the flat plate produces a local minimum at the stagnation point for short nozzle-to-plate distance, while a local maximum appears at the stagnation point for large nozzle-to-plate distance. When the stagnation bubble exists, the other maximum of heat flux is produced at the edge of bubble.

摘要

本文数值研究了超音速高温燃气射流撞击垂直平板的传热特性。首先，使用一个实验案例验证了数值方法，同时评估了不同的湍流模型用于传热预测。然后，通过一系列数值实验研究了多品种、喷嘴到板距离和喷嘴压力比对壁面传热的影响。不同湍流模型的比较表明，在所研究的三个模型中，分离法向激波的湍流粘度变化是不同的。此外，如果真正的多种燃烧气体混合为具有相同热物理特性的单一物质，压力和热通量分布与燃烧气体的结果相同。最后，当射流流场中没有滞留气泡时，平板上的热通量在较短的喷嘴到板距离的滞止点处产生一个局部最小值，而对于大的喷嘴，在滞止点处出现一个局部最大值。 - 到板的距离。当停滞气泡存在时，在气泡边缘产生另一个最大的热通量。