Abstract
Computer analysis of video pictures of tufts attached on the surface of a high speed train rear end body was carried out to investigate the wake of the train. The video pictures were digitized and loaded frame-by-frame into a harddisk of a computer using a video editor. Each picture frame was analyzed by the computer to identify angles of the tufts in the picture. From the time-series of angle data of the tufts, statistical data were obtained. Periodicity was found in the movements of the tufts, but the frequencies differed by the location. Antisymmetric periodic motion indicating an alternating shedding of large scale vortices was found when the movements of tufts averaged over a wide area on each side of the end body were analyzed.
