Aerodynamics of pointed forebodies at high angles of attack

Abstract

Aerodynamics of circular cylinders with conical shaped pointed forebodies is studied experimentally at a subcritical Reynolds number of around 10 5 Attention is focused primarily on the side force coefficient at high angles of attack which has a maximum value comparable to that of lift and drag The main objective is to minimize the side force, which may lead to a large undesirable yawing moment Effectiveness of several procedures such as surface roughness helical strakes modified tip geometries, and tip rotation is assessed Results suggest nose boom and tip rotation to be promising in achieving this objective Nomenclature A = cyclinder cross sectional area wd 2 /4of conical sections (Fig 1) Re = Reynolds number pVd/n, S = side force V -freestream velocity o: = angle of attack a i <*2 <*3 -a p ex angles of conical forebodies (Fig 1) fji = viscosity of air P = density of air co = angular velocity of conical tip