All-Ceramic Heat-Flux Sensor for Continuous Measurement Under High Temperature and Harsh Environmental Conditions
Helei Dong, Yanyan Niu, Hanyu Wang, Tao Liu, X. Li, Jijun Xiong, Yong Ruan, Qiulin Tan
Abstract
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 ultra-high temperatures and high heat-flux conditions. The sensor components comprised high temperature resistant ceramic materials, that is, alumina (Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> ), indium tin oxide (ITO)-In <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> thermopile, and nano SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> . 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 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> was 31.5 μV/(kW∙m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-2</sup> ). The drift rate of the proposed sensor in the high-temperature maintenance experiment at 1200 °C for 5 h was 2.7 (kW/m²)∙h <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> . The time constant of the sensor under pneumatic heating was 2.3 s. The proposed sensor can continuously work at ultra-high temperatures; therefore, it can be practically employed in the heat flux measurement of turbines and supersonic aircrafts.