High-Sensitive Thin Film Heat Flux Gauge With ITO/In2O3 Thermopile on Nickel Alloys for Turbine Blade Applications

Heat flux is key parameter for evaluating the heat dissipation of turbine blade. The accurate measurement of heat flux is vital for the optimizing cooling system and fabrication of turbine blade. The thin film heat flux gauge is usually fabricated on insulated substrate and located away from the measured area of turbine blade. As a result, the changes of heat flux on the surface of turbine blade cannot be reflected quickly and accurately. This paper innovatively designs membrane structure of thin film heat flux gauge on nickel alloys. The sensor is fabricated on the surface of the nickel alloys by thin-film depositing technology to realize in-situ surface heat flux measurement, and ITO/In ₂ O ₃ thermopile is used to replace precious thermopile to improve sensitivity. The results show that the sensitivity and response frequency of the sensor respectively are measured to be $61.93~\mu \text{V}$ /(kW/m ² ) and over 14400Hz respectively, which can measure heat flux of 236.4kW/m ² at $888^\circ \text{C}$ . Besides, the thin film heat flux gauge is fabricated on the surface of turbine blade to verify functional feasibility with same preparation process of that on nickel alloys, and can obtain reproducible results. This work suggest that the thin film sensor based on ITO/In ₂ O ₃ thermopile has great potential in applications used as optimizing cooling system of components in aeronautics and astronautics.