Temperature measurement on SD7003 airfoil using the single-shot lifetime method in a towing tank

Abstract

Time-resolved surface temperature measurements on the suction side of a SD7003 foil at a Reynolds number of 60000, where laminar separation bubbles occur, were successfully performed in a towing tank. The experiments were able to confirm the suitability of the singleshot lifetime method for studying the unsteady fluid dynamic phenomenon. To facilitate the visualization of the thermal fluctuations, a carbon-based electrically conductive paint is sprayed on the suction side of the wing. The footprints of Kelvin-Helmholtz vortices were observed by this method at angles of attack of α=2°, 4°, 6°, and 8°. The spanwise coherence of the vortices is high enough that their footprints on the model surface are still visible after spanwise averaging the thermal signal. This compensates for the low fluctuation amplitudes and improves the readability of the spectral content.