Abstract: A drag-stabilized water-entry projectile having a projectile body, one or more drag-stabilizing elements, such as fins, flares or canards, and one or more attachment members adapted to hold the one or more drag-stabilizing elements to the projectile body. The one or more attachment members are coated with a thermally reactive material. A projectile and cartridge assembly has a shear pin, a projectile having a first cutout portion, the cutout portion sized to receive the shear pin. The assembly also includes a sabot configured to house the projectile and having a second cutout portion, the second cutout portion sized to receive the shear pin. The cutout portion is positioned to provide an offset region between an aft end of the projectile and a base of the sabot.

Abstract: A supercavitating projectile having a nose that is capable of morphing its shape or length for extended operating range is disclosed.

Abstract: The illustrative embodiment provides bumpers which are roughly shaped like skis that face towards the air-water boundary of the air cavity. When the projectile fishtails and one or more of the bumpers come into contact with the air-water boundary, the water imparts torque and a rebounding force to push the projectile completely back into the air cavity. Furthermore, because the bumpers are shaped roughly like skis and not like knives, the bumpers do not penetrate the water or create unnecessary water drag.

Abstract: The illustrative embodiment provides bumpers which are roughly shaped like skis that face towards the air-water boundary of the air cavity. When the projectile fishtails and one or more of the bumpers come into contact with the air-water boundary, the water imparts torque and a rebounding force to push the projectile completely back into the air cavity. Furthermore, because the bumpers are shaped roughly like skis and not like knives, the bumpers do not penetrate the water or create unnecessary water drag.

Abstract: A surface ship, deck-launched anti-torpedo projectile is disclosed. The projectile has a blunt-end nose to create a cavitating running mode. The nose has a gradual, stepped, right-circular cylindrical or conic geometry. In some embodiments, the projectile includes a plurality of tail fins that are dimensioned and arranged to be within the generalized elliptical cavity that shrouds the projectile in the cavitating running mode.

Abstract: A supercavitating projectile having a nose that is capable of morphing its shape or length for extended operating range is disclosed.

Abstract: A cavity-enhancing feature and method are disclosed for a projectile that is capable of operating underwater in a cavity-running mode.

Abstract: A surface ship, deck-launched anti-torpedo projectile is disclosed. The projectile has a blunt-end nose to create a cavitating running mode. The nose has a gradual, stepped, right-circular cylindrical or conic geometry. In some embodiments, the projectile includes a plurality of tail fins that are dimensioned and arranged to be within the generalized elliptical cavity that shrouds the projectile in the cavitating running mode.

Abstract: A cavity-enhancing feature and method are disclosed for a projectile that is capable of operating underwater in a cavity-running mode.

Abstract: An apparatus and method for sealing the barrel of an underwater gun between firings is disclosed. The apparatus clears the barrel and/or prevents water from entering the barrel based on pressure variations.

Abstract: An apparatus and method for sealing the barrel of an underwater gun between firings is disclosed. The apparatus comprises an adapter that attaches to the barrel and includes a physical adaptation that is capable of sealing the barrel. In some embodiments, the physical adaptation is actuated to un-seal the barrel via combustion gases from firing of a round.

Abstract: A test system that is capable of evaluating the effectiveness of a weapons system designed to defeat an incoming, fast-moving, underwater munition is disclosed. In the illustrative embodiment, an extremely large tubular sheath is inflated underwater. The sheath is maintained at a depth and inclination that is appropriate for an incoming torpedo. An inert projectile is launched or flown inside the sheath at a speed that is consistent with the speed of munition that the weapons system is intended to defeat.

Abstract: A technique for controlling the pitch of a supercavitating projectile is disclosed. For example, the illustrative embodiment controls the pitch of a supercavitating projectile by shifting its center of gravity. The center of gravity of the projectile is shifted by moving a ferromagnetic mass inside the projectile forward or backward, depending on the desired pitch. In some embodiments of the present invention, the position of the ferromagnetic mass is directed by a controller that has a predetermined trajectory stored in its memory.

Abstract: A projectile having a cavity-running mode is provided with a means for changing the diameter of its nose. Based on changed conditions, the diameter of the nose can be actively reduced or increased, as required, to maintain a desired value for the nose-to-body ratio of the projectile.

Abstract: An apparatus for sealing the barrel of an underwater gun between firings is disclosed. The apparatus comprises a magnetically-attractable water-impermeable disk. Via operation of a drive system, the disk is movable between a sealing position, wherein it prevents water from entering the barrel by moving into alignment with the first bore, and a firing position, wherein the first water-impermeable disk moves out of alignment with the first bore.

Abstract: A projectile having a cavity-running mode is provided with a mechanism for changing the diameter of its nose. Based on changed conditions, the diameter of the nose can be actively reduced or increased, as required, to maintain a desired value for the nose-to-body ratio of the projectile.

Abstract: A method for operating a thrust-generating supercavitating projectile involves launching the projectile in water from rest at the maximum available thrust, maintaining that thrust until supercavitating movement begins, and then reducing thrust to a near-minimum amount that is required to maintain supercavitating movement of the projectile.

Abstract: An apparatus and method for sealing the barrel of an underwater gun between firings is disclosed. The apparatus comprises a turbine that is disposed at the outlet of the muzzle of the gun. The turbine draws in water and, in various embodiments, either (a) vaporizes it, forming a vapor barrier along the spin axis that keeps water out of the barrel, (b) expels it radially, thereby re-directing it so that it does not enter the barrel, or (c) generates water jets that prevent water from entering the barrel.

Abstract: A method for operating a thrust-generating supercavitating projectile involves launching the projectile at a velocity above the minimum required to maintain supercavitating movement, delaying initiation of thrust until the projectile slows to a velocity that is near that minimum velocity, and then applying thrust to maintain the near-minimum velocity until a target is reached.

Abstract: An apparatus for sealing the barrel of an underwater gun between firings is disclosed. The apparatus comprises a magnetically-attractable water-impermeable disk. Via operation of a drive system, the disk is movable between a sealing position, wherein it prevents water from entering the barrel by moving into alignment with the first bore, and a firing position, wherein the first water-impermeable disk moves out of alignment with the first bore.