Supercavitating water-entry projectile

Abstract

A supercavitating water-entry projectile having empennage on the aft end which provides both aerodynamic and hydrodynamic stability and a supercavitating nose section is provided. A representative projectile is a subcaliber munition adapted for use in a 25 mm weapon using a sabot currently in use with the M919 round. The projectile has circumferential grooves around its center section to match these sabots. A key feature in the invention is the size and shape of the nose section. The projectile has a novel high strength extended blunt nose section followed by a truncated conical section which angles towards the body of the projectile in the range of five degrees. During underwater trajectory, the entire projectile is contained within the cavitation bubble formed by the blunt nose tip. The projectile's aft empennage, which provides both aerodynamic and hydrodynamic stability, fits within the bore of the weapon.

Description

FIELD OF THE INVENTIONThe invention described herein relates to underwater projectiles and in particular to long-rod projectiles used for destroying underwater objects such as obstacles, torpedoes, and mines.BACKGROUND OF THE INVENTIONDevelopment of penetrating projectiles as currently used in anti-armor applications has addressed numerous technological difficulties in order to produce effective weapons. The basic requirements of a long-rod penetrator includes the use of high density projectiles having a long length-to-diameter ratio and having very high impact velocities. The presently available projectiles are generally used for maximum target penetration of a hardened structure. The invention adapts long-rod penetrators with the capability of traveling both in air and water where the object is to achieve low-drag water penetration for the purpose of delivering high kinetic energy to underwater targets. This requires that the hydroballistic projectile maintain stability and low dr...

AI Technical Summary

Benefits of technology

It is an object of the invention to provide an air-launchable, penetrating projectile which is ballistically stable both aerodynamically and hydrodynamically.

It is another object of the invention to provide a projectile having a supercavitating nose which provides a cavitation bubble of sufficient size to encompass the body of the projectile which reduces hydrodynamic drag.

In accordance with these and other objects, the invention is a supercavitating water entry projectile having aft mounted empennage which provides stabilization in both air and water and a supercavitating nose section. The projectile is a subcaliber, gun launched munitions using an appropriate sabot assembly to provide full caliber integrity. The projectile has circumferential grooves around its center section to match grooves in the sabot assembly. A key feature in the invention is the size and shape of the nose section. The projectile has a novel high strength extended blunt nose section followed by a truncated conical section which angles towards the body of the projectile in the range of five degrees. During underwater trajectory, the entire projectile is contained within the cavitation bubble formed by the blunt nose tip. The projectile's empennage, which provides both aerodynamic and hydrodynamic stability, fits within the bore of the weapon.

Problems solved by technology

Current projectiles do not exhibit the capability to travel in both air and water and deliver high kinetic energy to defeat targets at any significant depth below the water surface.

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