Construction of simultaneous measurement system of unsteady thermal and flow fields in the near-wall region using high-speed infrared thermography and PIV

Abstract

In the present study, a combined system of particle image velocimetry (PIV) and a high-speed infrared thermography (IRT) was employed to investigate turbulent flow in the unsteady thermal and flow fields. Simultaneous measurements of the velocity near a wall and the temperature on a heated thin-foil were conducted. The heat transfer coefficient was obtained from the temporal and spatial temperature data recorded at the thin-foil surface. Reynolds numbers based on main flow velocity and momentum thickness were 630, 1,050, 1,540, 2,290 at 10mm upstream from the heating start point. Uncertainties at the 95% confidence interval of the measured heat transfer coefficient and velocity are 2.8% and 2.4%, respectively. In the thermal and flow fields, the spatial distribution of heat transfer coefficient on the heated foil is similar to that of the streamwise velocity near the wall-region. It is concluded that there is the strong positive correlation between the fluctuations of the heat transfer coefficient and the streamwise velocity by the statistical procedure. © 2013 The Japan Society of Mechanical Engineers.