Hydrodynamic Characteristics of the 12.75 Inch Type X10 Antisubmarine Rocket

This laboratory was requested to recommend a nose design for the 12.75-inch Antisubmarine Rocket which would give a terminal velocity of 40 feet per second. Such a nose was to have a flat face with a diameter not less than half the projectile diameter. Two designs are submitted herein. The diagram shows their outlines together with that of the original nose. Calculations indicate that either should give a terminal velocity between 47 and 48 feet per second in sea water of 60° Fahrenheit (with 23.7 lbs. of water in discharged motor tube, 45 ft/sec if empty). These nose shapes are sufficiently different to afford considerable latitude in respect to characteristics of maximum range, ricochet, cavitation, and performance in the entry bubble. It is unlikely that any other nose shape could further materially reduce the drag while other components remain unchanged. The new noses have trivial effect on the cross force coefficient developed with the original nose and all have considerable static stability.