抄録
Aerodynamic characteristics which are important to design aircraft are closely related with the flow around a body. In studying this flow, recently the analysis of fluid model considering the properties of three dimensions is done briskly. But the flow around three dimensional body is different from the case of two dimension, and is not clearly defined in the existing circumstances, because there are various separation patterns for the magnitude of attack angle, and these patterns are complicately combined with the others. In this study, it is the purpose to make clear experimentally the separation of boundary layer around three dimensional body having an angle of incidence, the patterns of back flow domain, and the structure of vortex. For this purpose, in water tank experiment, a revolving projectile is set to various angle of incidence, limiting stream line and vortex on it are visualized. And in this study some conclusions were got. At firstly, limiting stream line around a revolving projectile could be visualized using phenolphthalein method. Secondly, the flow around a revolving projectile were classified into the domain A of boundary layer flow in which there were fore flows in the bus and circumferential directions, and the domain B in which there were back flows in the bus and circumferential directions, and the domain C in which there were fore flow in the bus direction and back flow in circumferential direction, and the domain D in which there were back flow in the bus direction and fore flow in circumferential direction. And it was elucidated that the extent of separation domain from B to D had magnified as the angle of incidence had increased. Moreover, it was found out that the vortex pattern existed behind the revolving projectile at attack angle 50°. Finally it was found that the primary separation line could be changed a closed separation line at attack angle 65°.
