An Experimental Investigation of the Flow Field of an Ejector Wing Design Employing a Photon Correlation Laser Velocimeter

摘要

The flow field about a dual element airfoil model employing an ejector for aerodynamic blowing is investigated. Flow visualization is obtained by smoke tunnel testing. Mean velocities and turbulence intensities are determined at various flow field locations. All data is obtained through the use of a Laser Doppler Velocimeter (LDV) using a photon correlation processing scheme. Flow field properties are computed from the LDV generated autocorrelation function. The free stream velocity and Reynolds number based on model chord length are 8 m/sec and 325,000 respectively. Two ejector velocity ratios are investigated: (U) ejector/(U) free stream = 0. and 2. Flow visualization photography is conducted at seven angles of attack: -5 deg, 0 deg, 5 deg, 10 deg, 15 deg, 20 deg, and 25 deg and LDV data is acquired at 0 deg and 15 deg angles of attack. The results are presented in the form of flow visualization photographs and profiles of mean velocities and turbulence intensities. Conclusions are drawn concerning the aerodynamic benefit of the ejector wing design for possible V/STOL applications. (Author)