caa a22 4500 606197222 CHVBK 20210128100928.0 cr unu---uuuuu 210128e20150601xx s 000 0 eng 10.1007/s00348-015-1963-1 doi (NATIONALLICENCE)springer-10.1007/s00348-015-1963-1 Aerodynamics of dynamic wing flexion in translating wings [Elektronische Daten] [Yun Liu, Bo Cheng, Sanjay Sane, Xinyan Deng] We conducted a systematic experimental study to investigate the aerodynamic effects of active trailing-edge flexion on a high-aspect-ratio wing translating from rest at a high angle of attack. We varied the timing and speed of the trailing-edge flexion and measured the resulting aerodynamic effects using a combination of direct force measurements and two-dimensional PIV flow measurements. The results indicated that the force and flow characteristics depend strongly on the timing of flexion, but relatively weakly onitsspeed. This is because the force and vortical flow structure are more sensitive to the timing of flexion relative to the shedding of starting vortex and leading-edge vortex. When the trailing-edge flexion occurred slightly before the starting vortex was shed, the lift production was greatly improved with the instantaneous peaklift increased by 54% and averaged lift increased by 21% compared with the pre-flexed case where the trailing-edge flexed before wing translation. However, when the trailing-edge flexed during or slightly after the leading-edge vortex shedding, the lift was significantly reduced by the disturbed development of leading-edge vortex. The force measurement results also imply that the trailing-edge flexion prior towing translation does not augment lift but increases drag, thus resulting in alowerlift-drag ratio as compared to the case of flat wing. Springer-Verlag Berlin Heidelberg, 2015 Liu Yun School of Mechanical Engineering, Purdue University, 47906, West Lafayette, IN, USA aut Cheng Bo Department of Mechanical and Nuclear Engineering, Pennsylvania State University, 16802, University Park, PA, USA aut Sane Sanjay National Center for Biological Sciences, Tata Institute of Fundamental Research, GKVK Campus, Bellary Road, 560 065, Bangalore, India aut Deng Xinyan School of Mechanical Engineering, Purdue University, 47906, West Lafayette, IN, USA aut Experiments in Fluids Springer Berlin Heidelberg 56/6(2015-06-01), 1-15 0723-4864 56:6<1 2015 56 348 https://doi.org/10.1007/s00348-015-1963-1 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00348-015-1963-1 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Liu Yun School of Mechanical Engineering, Purdue University, 47906, West Lafayette, IN, USA aut NATIONALLICENCE 700 1- Cheng Bo Department of Mechanical and Nuclear Engineering, Pennsylvania State University, 16802, University Park, PA, USA aut NATIONALLICENCE 700 1- Sane Sanjay National Center for Biological Sciences, Tata Institute of Fundamental Research, GKVK Campus, Bellary Road, 560 065, Bangalore, India aut NATIONALLICENCE 700 1- Deng Xinyan School of Mechanical Engineering, Purdue University, 47906, West Lafayette, IN, USA aut NATIONALLICENCE 773 0- Experiments in Fluids Springer Berlin Heidelberg 56/6(2015-06-01), 1-15 0723-4864 56:6<1 2015 56 348