General formula for the temporal and spatial resolutions in measuring the heat transfer fluctuation on a thin-film heater formed on a window material by infrared camera

Abstract

To measure the high-speed temporal and spatial fluctuation of convective heat transfer, there is a method of measuring the temperature distribution of thin film heater formed on a window material with a high-speed infrared camera. However, due to the thermal inertia and heat conduction of the window material, the temperature fluctuation of the thin film is attenuated temporally and spatially, and the resolution of the measurement deteriorates. In this study, we conducted a heat conduction analysis of the heat transfer surface when heat transfer fluctuated temporally and spatially, and derived a general relationship of the upper limit of fluctuation frequency and the lower limit of spatial wavelength detectable.