During atmospheric reentry at hypersonic speed and during very-high-speed flight in the atmosphere, vehicles experience extremely high thermal loads for relatively long time. To handle this problem, classical thermal protection materials may need to be replaced with lightweight actively cooled components. This work investigates experimental film cooling of a blunt body in a supersonic high-enthalpy flow. The coolant injected from the center of the blunt body surface against the freestream generates a thin, cool insulating layer, yielding a thickening of the boundary layer, thus reducing the temperature gradient and the resulting heat flux to the surface. Experiments were performed in the Aerothermodynamics Laboratory of the Technion–Israel Institute of Technology, where a 5 MW arc plasma tunnel enables simulation of high-enthalpy flows. Two models (with and without injection) were exposed to a Mach 2.2 freestream with a total enthalpy of $1.7\mathrm{MJ}/\mathrm{kg}$. Nitrogen and helium were used as coolants gases. A parametric study shows the influence of coolant physical properties and mass flow rate on the characteristics of the flow surrounding the model and on the resulting temperature reduction at different locations on the test model.

在以高超音速进入大气层并在大气中进行超高速飞行期间，车辆会在相当长的时间内承受极高的热负荷。为了解决这个问题，可能需要用轻巧的主动冷却组件来代替传统的热保护材料。这项工作研究了超声速高焓流中钝体的实验膜冷却。从钝体表面的中心向自由流喷射的冷却剂产生了一层薄而凉的绝缘层，使边界层变厚，从而降低了温度梯度并降低了向表面的热通量。实验是在以色列理工学院的空气热力学实验室中进行的，该实验室的5 MW电弧等离子体隧道可以模拟高焓流。$1.7\mathrm{MJ}/\mathrm{公斤}$。氮气和氦气用作冷却剂气体。参数研究显示了冷却剂物理性质和质量流量对模型周围流动特性以及在测试模型上不同位置所导致的温度降低的影响。