Direct and Simultaneous Measurement of Wall-Heat Flux and Temperature in a Shock Tube by Atomic Layer Thermopiles

This study focuses on the static and dynamic analysis and calibration experiments of Atomic Layer Thermopile (ALTP) sensors exposed to a traveling shock wave at the side and end wall of a shock tube. A newly developed methodology allows direct and simultaneous measurement of heat-flux density and temperature in ALTPs. The heat flux at the end wall of the shock tube is directly measured by an ALTP-sensor and is compared with analytical end-wall solutions. The analytical heat-flux progression is derived from estimations for post-reflected shock conditions based on the pressure data and 1-D computations. The experimental data compare well with the time-invariant analytically-determined heat-flux progression for lowand high-pressure conditions. In addition, the dynamic response of heat flux as well as of temperature is investigated: ALTP-sensor response on the side wall compares well with optical dynamic calibration results. The response of the end-wall sensor significantly underestimates the optically predicted response times. For the first time, the dynamic response of ALTP temperature data could be investigated in short-duration shock tube experiments and compared with coaxial thermocouple readings.