Experimental Investigation of Surface Flow Structure over Non-slender Diamond Wing

The experimental study focuses on investigating the aerodynamic flow structure and the characteristics over non-slender diamond wing having low sweep angle (Λ = 51°). The vortical flow on the surface of the non-slender diamond models was investigated using dye-flow visualization and a stereoscopic particle image velocimetry (SPIV) technique. The near-surface flow structure, topology, and the formation of the vortex breakdown over the wing were also studied by varying the angle of attack α within the range of 5° ≤ α ≤ 25°. Experimental analysis is composed of the time-averaged patterns of streamlines, contours of vorticity distributions, and stream-wise velocity components for interpreting flow physics. It was concluded that vortex breakdown occurred farther upstream from the trailing edge of the wing at low angle of attack. However, once the angle of attack increased, formation of the vortex breakdown occurs farther downstream. So the location of vortex breakdown moved to the apex of the wing as the angle of attack increases. And the flow over the wing was fully stalled when the angle reaches α = 25°.