High Temperature Heat Flux Sensor With ITO/In2O3 Thermopile for Extreme Environment Sensing

Abstract Hypersonic vehicles and aircraft engine blades face complex and harsh environments such as high heat flow density and high temperature, and they are generally narrow curved spaces, making it impossible to actually install them for testing. Thin-film heat flux sensors(HFSs) have the advantages of small size, fast response, and in-situ fabrication, but they are prone to reach thermal equilibrium and thus fail during testing. In our manuscript, an ITO-In2O3 thick film HFS is designed and a high-temperature heat flux test system is built to simulate the working condition of a blade subjected to heat flow impact. The simulation and test results show that the test performance of the thick-film HFS is improved by optimizing the structure and parameters. Under the condition of no water cooling, the designed HFS can work under the extremely high temperature environment of 1450°C, with the maximum output thermopotential of 17.8 mV, and the average test sensitivity of 0.035 mV/(kW/m2), which has a superior high temperature resistance performance, which cannot be achieved by other existing thin (thick) film HFSs. Therefore, designed HFS has a great potential for application in harsh environments such as aerospace, weaponry, and industrial metallurgy.