Computation of the Hydrodynamic Forces and Moments on a Body of Revolution with and without Appendages
DEFENSE ADVANCED RESEARCH PROJECTS AGENCY ARLINGTON VA
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An analytical method was developed to predict the hydrodynamic forces and moments developed on a body of revolution with and without appendages. The appendages included a bridge fairwater, sternplanes, and rudders. It was assumed that the body was either translating with an angle of attack of up to 20 deg or rotating with an angular velocity. Calculations were performed by using the analytical method for four different bodies of revolution and comparisons were made with available experimental data. Potential flow was used to determine the inviscid contribution to the hydrodynamic forces and moments. The viscous contribution to the hydrodynamic forces and moments was determined by assuming that there was no flow separation due to the axial flow, and that the flow separation on the leeward side of the body due to the crossflow was independent of the offsets of the body, the angle of attack, the angular velocity, and the forward speed. It was assumed that the angle at which the flow separates, as measured from the stagnation point, was 110 deg at the stern and 170 deg at the bow for the body at angle of attack and 160 deg for the body with an angular velocity.
- Submarine Engineering
- Fluid Mechanics