タンポポ冠毛後流の可視化

抄録

There are two kinds of seeds that fly by wind, pappose seeds and winged seeds. The former is known to make parachuting flights, which utilize the drag force acting on the pappi. Each flying seed is designed to have a small rate of descent and to float in the air current as long as possible, according to their environmental conditions. The dandelion which is a common example of wind-dispersed plant has an intricate haired pappus facilitating flight. In the present study, in order to investigate the effect of the posture of the pappus with respect to the flow direction on generating drag, drop tests were performed and the flight behavior of the pappus is observed by using a high speed video camera. The falling speed of the pappus is strongly dependent on posture in the air current.