Hot Wire Measurements Around a CD Airfoil in an Open-Jet Anechoic Wind Tunnel

Abstract

The aeroacoustic measurements in the ECL large anechoic wind tunnel, which originally focused on the wall pressure distribution and the far field acoustic pressure are extended to velocity measurements by hot-wire probes in the nozzle jet and in the vicinity of the subject airfoil. The present work focuses on the exit plane of the wind tunnel nozzle upstream of the test airfoil and in the LES computational domain that is embedded in the potential core around the airfoil mock-up at mid span. The inlet measurements by a single hot-wire probe provide some insight on free-stream turbulence intensity upstream of the profile. The X-array measurements on the upper and lower LES boundaries show the overall deflection of the jet potential core by the cambered airfoil. These are compared to the Fluent RANS predictions. The X-array measurements in the airfoil wake provide information on the development of the airfoil boundary layer and the resulting wake after separation. The measured wake velocity defect has been compared with both the RANS and LES predictions.