AVT-183 diamond wing flow field characteristics Part 2: Experimental analysis of leading-edge vortex formation and progression

Experimental flow field investigations are presented on a 53° leading-edge sweep diamond wing configuration with rounded leading-edge contour. The analyses pertain to recent work that was conducted within the NATO Science and Technology Organization (STO) task group AVT-183 (Applied Vehicle Technology panel). The results obtained in a low-speed wind tunnel facility depict the overall aerodynamic characteristics as function of the angle of attack, and mean and turbulent flow field characteristics at one specific angle of attack, namely α=12°. Both Stereo Particle Image Velocimetry and Hot-Wire Anemometry are applied to detect the emerging flow phenomena in several chordwise sections including near-wall data. Details of the leading-edge vortex formation and progression are analyzed and discussed. Over almost the entire length of its existence, the leading-edge vortex is characterized by retarded axial flow, thus showing vortex bursting tendencies. The corresponding turbulent fluctuations show maxima close to the evolution of the leading-edge vortex and decrease towards the trailing edge. The observed flow separation onset and progression are significant for the AVT-183 diamond wing configuration, and more generally for a moderately-swept low-aspect-ratio wing with rounded leading-edge contour. Following, the derived flow field characteristics provide a high-quality data base, which is suitable for general CFD validation.