Heat Transfer Measurements on a Ramp Model in the High Enthalpy Shock Tunnel (HEG) using Temperature Sensitive Paint

Kurzfassung

Temperature measurements using temperature sensitive paint (TSP) have been carried out on a ramp model placed in a hypersonic flow in the DLR High Enthalpy Shock Tunnel (HEG) in order to demonstrate the feasibility of measuring heat transfer into the model surface. 50 fluorescence intensity images over 10 ms were acquired, from which, with the help of calibration data, temperature field data on the model surface were determined. From these the heat load into the surface was calculated, with application of the assumption of a one-dimensional, semi-infinite heat transfer model. The validity of this model, as well as a critical assessment of measurement uncertainties, derived from statistical error sources and the long luminophore relaxation times (relative to camera exposure time), are then discussed.