AEROSPACE SCIENCE AND TECHNOLOGY, cilt.28, sa.1, ss.417-430, 2013 (SCI-Expanded)
The aim of the current study at first stage is to demonstrate the general flow structure qualitatively using the dye visualization technique. Secondly, the instantaneous flow data taken by a Stereoscopic Particle Image Velocimetry (stereo-PIV) over a stationary nonslender lambda wing is used to determine the time-averaged flow topology in order to provide detailed information about crucial events like formation of leading edge vortices and vortex breakdown in plan-view planes and cross-flow planes. The flow structure close to the lambda wing surface and development of the vortex breakdown are investigated as functions of angles of attack within the range of 7 degrees <= alpha <= 17 degrees. Experimental analyses are composed of time-averaged patterns of streamlines, vorticity contours, transverse and streamwise velocity components, Reynolds-stress correlations, distribution of fluctuating velocities, and turbulent kinetic energy. Results show that the angle of attack has a substantial influence on the flow behavior on the nonslender lambda wing surface. (C) 2013 Elsevier Masson SAS. All rights reserved.