Impulsively-Started Flow about Submarine-Shaped Bodies

摘要

Impulsively-started flow about a D-shaped body, a T-shaped body, and a flat plate has been investigated. The forces and moments acting on the bodies have been determined, as a function of the relative displacement of the fluid at a subcritical Reynolds number, for various angles of attack. The results have shown that the shedding of the first two or three vortices and the manner in which they are generated have profound effects on all the characteristics of resistance. The evolution of the vortices, and hence the forces, significantly depend on whether the separation points are fixed or mobile, or a combination thereof. The data presented are expected to form the basis for future numerical analyses of the characteristics of time-dependent flow about bluff bodies. At present accurate analytical and numerical data, for comparison with those presented do not exist.