Infrared Thermography in Expansion Tubes for Martian Entry Flows

two dimensional heat transfer measurements at planetary re-entry conditons. Experiments were performed in the X2 Expansion Tube at The University of Queensland in a simulated Martian (CO2/N2) test gas on a wedge model. An infrared camera and sensor were used in these experiments. Infrared filtering to remove radiation outside of the 3.5 -4 µm waveband was found to be sufficient to eliminate direct radiation from the shock layer. The infrared camera was used for radiation measurements from which surface temperature maps were deduced. The infrared sensor was used to obtain a time resolved variation of the surface temperatures from which heat flux can be deduced. The model surface was pre-heated to two different temperatures to assess the signal to background ratios for infrared thermography. These results indicate infrared thermography can be used for obtaining two dimensional heat transfer on blunt bodies at speeds of ∼ 5.6 km/s in a Mars test gas.