THEORETICAL PREDICTION OF VORTEX INTERFERENCE EFFECTS ON THE STATIC STABILITY OF A HIGH-SPEED SUBMARINE. PART I: ANALYSIS

• Main Author: Spangler,Selden B
• Format: Report
• Language: English
• Subjects: ANGLE OF ATTACK; HYDRODYNAMICS; HYDROSTATICS; INTERFERENCE; MATHEMATICAL PREDICTION; MOMENTS; PITCH(MOTION); ROLL; SLENDER BODIES; STABILITY; SUBMARINE HULLS; SUBMARINES; VORTICES; WAKE

Methods are presented for theoretically predicting the forces and moments induced on the hull and stern control surfaces of a high-speed submarine by the vortex wake shed from the fairwater and fairwater planes at angles of attack, drift, and fairwater plane deflection. The methods are limited to those angles of attack and/or drift at which hull flow separation does not occur (the order of 10 degrees or less). The methods are applied to an assumed submarine configuration in order to illustrate the relative importance of the various vortex wake effects. For this purpose, forces and moments in the absence of vortex interference are predicted in order to obtain total forces and moments. Vortex interference effects induced by the fairwater plane wake at angle of attack are found to be negligible. Vortex interference effects are found to be small but not negligible for side force and to be appreciable for normal force, pitching moment, and rolling moment at angle of drift and for all forces and moments at combined angles of attack and drift. (Author)