Aerodynamics of a circular cylinder with conical shaped forebodies is studied at a subcritical Reynolds number of around lo5. Attention is primarily focused on modification of the forebody geometry to minimize the side force coefficient at high angles of attack. The tip geometries used are: the standard cone; a family of nose-booms; a set of delta strakes, porous tips; spinning nose-boom tips, and their combinations. The effectiveness of each tip in reducing the side force is assessed over a range of flight conditions, and compared with the standard tip data. The results suggest that such tip modifications can reduce the side force in the range of 50% -88%. NOMENCLATURE base area of cone, aD2/4 aspect ratio coefficient of normal force, normal force/(q . Ab) coefficient of pressure, P/q coefficient of side force, side force/(q . A*) cone base diameter total cone length nose-boom length strake length local and reference free-stream static pressures, respectively free-stream dynamic pressure head, (1/2)PV: Reynolds number, pV, D / p local and free stream velocities, respectively angle of attack yaw angle cone half-angle density angular circumferential position of a pressure tap angular position in roll w.r.t. a fixed reference frame dynamic viscosity

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Aerodynamics of a circular cylinder with conical-shaped forebodies is studied at a subcritical Reynolds number of around 10 s . Attention is primarily focused upon modification of the forebody geometry to minimize the side force coefficient at high angles of attack. The tip geometries used are the standard cone, a family of nose booms, a set of delta strakes, porous tips, spinning nose-boom tips, and their combinations. The effectiveness of each tip in reducing the side force is assessed over a range of flight conditions and compared with the standard tip data. The results suggest that such tip modifications can reduce the side force in the range of 50-88%. Nomenclature= nose-boom length L s = strake length P, POO = local and reference freestream static pressures, respectively q = freestream dynamic pressure head, (l/2)pFj, Re = Reynolds number, pV^ D/p V, V^ -local and freestream velocities, respectively a.= angle of attack (3 = yaw angle <5 = cone half-angle 0 = angular position in role with respect to a fixed reference frame //, = dynamic viscosity p = density = angular circumferential position of a pressure tap