Abstract: Based on v isualizing and tr acking t he flow by smoke stream and surface pr essure measurement, the entire process o f t he flow behavior around a slender og ive cylinder at angles of at tack from 0°to 90°is observ ed and analy zed systematically. It is found that in the exper iment, at various angles of attack, the structur e of the flowfieldaround the slender body is differ ent and the r ange of the angles of attack invo lved by the evolvement process is small.The evolvement pro cess can mainly be finished in a small rang e of angles of attack.

Key words: slender body, asymmetric vortices, high angle of attack, flow visualization, unsteady character