涡结构和翅运动学:短耳犬蝠(拉丁文学名Cynopterus brachyotis)的飞行
We investigated the detailed kinematics and wake structure of lesser dog-faced fruit bats (Cynopterus brachyotis) flying in a windtunnel. High speed recordings of the kinematics were conducted to obtain three-dimensional reconstructions of wing movements.Simultaneously, the flow structure in the spanwise plane perpendicular to the flow stream was visualized using time-resolvedparticle image velocimetry. The flight of four individuals was investigated to reveal patterns in kinematics and wake structuretypical for lower and higher speeds. The wake structure identified as typical for both speed categories was a closed-loop ringvortex consisting of the tip vortex and the limited appearance of a counter-rotating vortex near the body, as well as a small distallylocated vortex system at the end of the upstroke that generated negative lift. We also investigated the degree of consistencywithin trials and looked at individual variation in flight parameters, and found distinct differences between individuals as well aswithin individuals.Supplementary material available online at http://jeb.biologists.org/cgi/content/full/213/20/3427/DC1Key words: bat flight, kinematics, wake structure.