All-Ceramic Heat-Flux Sensor for Continuous Measurement Under High Temperature and Harsh Environmental Conditions.

In this study, an all-ceramic heat-flux sensor with high-temperature resistance and no water-cooling system was designed to address the problems of short effective lifespan and low sensitivity of heat-flux sensors under harsh ultrahigh temperatures and high heat-flux conditions. The sensor components comprised high-temperature resistant ceramic materials, that is, alumina (Al2O3), indium tin oxide (ITO)-In2O3 thermopile, and nano-silicon oxide (SiO2). Structural parameters of the proposed heat-flux sensor were optimized via simulations. A high-temperature test platform was built to evaluate the sensor performance; the sensor exhibited an excellent thermoelectric performance. The output voltage of the sensor reached 9.96 mV at 1300. C, and the average sensitivity in the range of 50-340 kW/m(2) was 31.5 mu V/(kW.m(-2)). The drift rate of the proposed sensor in the high-temperature maintenance experiment at 1200 degrees C for 5 h was 2.7 (kW/m2).h(-1). The time constant of the sensor under pneumatic heating was 2.3 s. The proposed sensor can continuously work at ultrahigh temperatures; therefore, it can be practically employed in the heat-flux measurement of turbines and supersonic aircraft.