| Summary: | This paper presents a novel experimental technique where infrared thermography is employed to directly measure
the surface heat transfer of a transpiration-cooled porous material in transient hypersonic flow. Experiments were
conducted in the Oxford High Density Tunnel on a flat-faced hemispherical probe at a single Mach 7 freestream
condition (Reu � 3.84 ⋅ 106 m−1) with nitrogen, air, argon, krypton, and helium injection gases and mass flow rates
ranging from 0.01 to 0.235 kg ⋅ s−1 ⋅ m−2. Surface heat transfer measurements were extracted by imaging directly on the porous material using a FLIR A6751 high-speed long-wave infrared camera. Porous alumina was chosen due to its favorable thermal properties for infrared analysis and its very small pore sizes (≈2 μm) enabling a uniform outflow. It
was found that the surface Stanton number reduction matched to within 10% of both computational fluid dynamics
results and correlations.
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