Abstract:
An apparatus and method for sealing the barrel of an underwater gun between firings is disclosed. The apparatus comprises a valve that is moved between a sealing and non-sealing state by a valve-actuator. In some embodiments, the valve actuator is driven by gases that result when a round is fired.
Abstract:
A projectile system includes an enclosure, first and second propellants and first and second projectiles. The first and second propellants are disposed within the enclosure. The first projectile is disposed within the enclosure between the first propellant and a first end of the enclosure, and is operable to exit the enclosure via the first end in response to detonation of the first charge. The second projectile is disposed within the enclosure between the second propellant and a second end of the enclosure, and is operable to exit the enclosure via the second end in response to the detonation of the second propellant.
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 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:
A mechanism for empirically deriving the values of the damping ratio and frequency of the mechanism driven by a servo-controlled control system is disclosed. In accordance with the illustrative embodiment, the values of the damping ratio and frequency are continually re-generated based on empirical data derived from sensor feedback of the maximum-amplitude switch and the linear second-order servo. Because the values of the damping ratio and frequency are generated from empirical data, it is not necessary that they be known, and because the values of the damping ratio and frequency are continually re-generated, variances in their values are continually noticed and compensated for.
Abstract:
An apparatus and method for sealing the barrel of an underwater gun between firings is disclosed. The apparatus comprises a valve that is moved between a sealing and non-sealing state by a valve-actuator. In some embodiments, the valve actuator is driven by gases that result when a round is fired.
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.