Wake dynamics of tapered wings. Part II: an experimental study

View Video Presentation: https://doi.org/10.2514/6.2023-2298.vid An experimental investigation was performed to illuminate the effects of sweep and taper on separated flows over wings at low Reynolds numbers. Two experimental finite wing models were tested one with a leading edge swept back 30 degrees with a straight trailing edge, and one with a straight leading edge and a trailing edge swept forward 30 degrees. Since the semi-aspect ratio of these wings were both 2, these combinations of leading and trailing edge sweep angles result in a taper ratio of 0.269 for both wings. The volumetric mean flowfields over these wings were measured using Stereo Particle Image Velocimetry at a Reynolds number of 600. Increasing the angle of attack results in an increase of the separation bubble size, which is shifted near the tip for the leading edge swept back case, and is stuck onto the wall near the root of the trailing edge swept forward case. Streamwise vortical structures form in the wake and are deflected notably towards the wall for the trailing edge forward case. The maximum unsteadiness in the leading edge swept back case is closer to the tip, whereas it is closer to the root for the trailing edge swept forward case. These differences in the wake structure are shown to lead to a much larger wake with more complicated interlocking patterns in the Reynolds shear stresses for the trailing edge swept forward case.