Accurately monitoring heat flux distribution can enhance the service stability of aeroengine hot-end components. The extreme environmental temperature and fast heat transfer between high-speed load and hot components propose serious requirements for heat flux sensors, including high-temperature resistance and fast response. This article fabricates the fast response thin film heat flux sensor based on the transverse thermoelectric (TTE) effect of La _1-x Ca _x MnO ₃ (LCMO). The TTE heat flux sensor shows excellent high-temperature resistance at 1000°C. After high-temperature heat treatment for 1 h, the performance of the sensor is improved due to the optimization of the crystal quality and biaxial texture of the LCMO thin film, as well as the reduction of resistance. The sensitivity increases from 7.39 μV/(kW/m ² ) to 7.79 μV/(kW/m ² ), and the response time reduces from 58 ns to 42 ns. Then, the performance of the thin film heat flux sensor shows little changes after completing high-temperature heat treatment for up to 7 hours at 1000°C. The TTE heat flux sensor can show a satisfied response in a high-temperature environment at 1000°C, with a sensitivity of 1.18 μV/(kW/m ² ) without the consideration of laser absorption. The TTE heat flux sensor exhibits stable high-temperature resistance at 1000°C and can operate normally at 1000°C, indicating its potential in fast heat flux measurement for harsh environments.

Measuring the heat-flux density is one of the main tasks in the research field of hypersonic experimental aerodynamics. Considering the fact that refined wind tunnel tests require small-sized sensors, and the sensitivity of atomic layer thermopile (ALTP) heat-flux sensor is dependent on the effective length of the sensitive element, the sensitive elements are connected in series by conductive films. New-generation ALTP sensors with multiply enlarged sensitivities are developed in this study. The general features of new ALTP sensors, including the sensitivity, linearity and amplitude-frequency curves, are obtained by static and dynamic calibration tests. Then a discussion is presented on the tradeoff between high sensitivity and fast dynamic response. Finally, the practice performance of new ALTP sensors is confirmed by experiments conducted in the hypersonic low-density wind tunnel, since the frequently used thin-skin calorimeters and infrared thermographic techniques have the problems of short effective time and low signal-to-noise ratio.