Synergetic Optimization and In Situ Fabrication of Thin-Film Heat Flux Sensor for Heat Flux Measurement of Combustion Wind Tunnel

Instantaneous heat flux monitoring of hightemperature components in extreme environments is gaining significant attention for aircraft engines. Recently, advancements in microfabrication techniques have enabled the development of thin film heat flux sensor (TFHFS). However, fabricating TFHFS on complex aeroengine components, especially in narrow space, remains a significant challenge. In this wok, the influence of geometric parameters on the sensor’s physical properties is systematically investigated using numerical simulation methods. Then, a high temperature Pt-PtRh thermopile TFHFS is fabricated on a Ni-based turbine blade. Experimental results indicate that the proposed TFHFS exhibits a high sensitivity of 19.38 μV/(kW/m2) and a response time of approximately 21 ms. Notably, the TFHFS has a nearly constant response in three cycle tests, exhibits excellent repeatability and stability. Furthermore, the high temperature combustion wind tunnel test confirms that the TFHFS can operate up to 1000 °C and withstand gas flow velocity of 0.9 Mach, indicating that the fabricated TFHFS is suitable for extremely hostile and complex environment measurement applications. This study provides a viable approach for developing various thin-film sensors on complex surfaces and promotes in situ sensing toward practical applications.