Abstract: Various exemplary embodiments of an increased aperture homing cavitator are disclosed. In one exemplary embodiment, a supercavitating body may include, e.g., but may not be limited to, a cavitator assembly having a front end and a back end, and having a shape operative to generate a concave cavity; an acoustical homing array coupled to the cavitator assembly; an afterbody coupled to the back end; a thruster coupled to the afterbody; and a ventilation system disposed within the afterbody, operative to supply gas to, and to maintain pressure within the cavity. In an exemplary embodiment, the size of the cavitator may be increased without a significant attendant increase in drag, thereby enabling a homing array of increased size and aperture.

Abstract: An exemplary embodiment of the present invention may include a cavitating body sonar system and method.

Abstract: A stabilizing device for a supercavitating vehicle that isolates re-entrant jet flows of liquid from its cavity. The device has a receiving means positioned on the supercavitating vehicle where the re-entrant jet flow impinges on the supercavitating vehicle. An exit means is joined to the receiving means for carrying the received re-entrant jet flow out of interference with the cavity. The exit means includes an exhaust nozzle joined to the aft of the supercavitating vehicle and a re-entrant jet nozzle positioned in communication between the receiving means and said exhaust nozzle transferring said received re-entrant jet flow into the exhaust nozzle. This stabilizes the cavity and improves controllability and maneuverability of the supercavitating vehicles while also reducing the gas ventilation required to maintain the cavity. Furthermore, this reduces self-generated noise allowing improved operation of acoustical sensors incorporated in the vehicle.

Abstract: An actuated recoil absorbing mounting system is used to reduce recoil velties and to absorb the recoil energy from an underwater projectile launcher, such as a high discharge energy underwater gun. The recoil absorbing mounting system includes a projectile launcher frame that supports the projectile launcher during firing. The projectile launcher frame is slideably supported by one or more launcher frame supports to allow movement substantially in a linear direction. One or more recoil plates are coupled to the underwater projectile launcher frame to provide hydrodynamic added or virtual mass and damping to the projectile launcher frame and projectile launcher. The recoil absorbing mounting system further includes one or more actuators for repositioning or returning the projectile launcher frame and projectile launcher to an original position after firing.

Abstract: A flow control system is used to control fluid flow at the boundary layer an object or body about or within which the fluid flows relative to the body. The flow control system includes an actuated membrane that is displaced in a direction substantially tangential to the actuated membrane, thereby causing a disturbance or modified shear stress distribution in the boundary layer fluid flow. One or more sensor elements are disposed proximate a top region of the actuated membrane for sensing fluid conditions at the boundary layer flow. A membrane actuator provides the displacement, for example, by extending or contracting the actuated membrane in a direction substantially tangential to the actuated membrane. A feedback device is responsive to a system of sensor elements and is coupled to a system of membrane actuators to cause the displacement in one or more regions of the actuated membrane in response to the sensed fluid conditions.

Abstract: A baffled muzzle brake and seal system for submerged gun operation includes a muzzle brake chamber mounted to the muzzle of a submerged gun barrel. A baffle assembly mounted within the chamber deflects the propellant gasses produced by operation of the gun and sabot fragments into an annular cher surrounding the baffle assembly while allowing passage of a projectile through the assembly. A valve seal in the muzzle end of the muzzle brake chamber cycles between a fully open condition, to allow passage of the projectile, and a fully closed position, to seal the muzzle brake chamber against the entry of water. At least one pressurized air input allows the muzzle brake chamber to be pressurized when the seal is not in the fully closed position, thereby preventing entry of water. A gas exhaust provides a means for removing propellant gasses from the chamber.

Abstract: The present invention relates to an underwater weapon having a barrel with n opening through which a projectile is discharged. The weapon further has an apparatus for pressurizing the interior of the barrel to a pressure greater than the ambient pressure to keep water from entering the gun barrel at any point around the circumference of the muzzle opening. The pressurizing apparatus includes a source of gas, a pressure regulator for adjusting the flow of the gas and the pressure within the barrel, and a distribution network for distributing the gas near the muzzle opening and at an end of the barrel remote from the muzzle opening.

Abstract: A test assembly for testing an underwater gun in a tank of liquid includes or disposition in the tank in the liquid, a mount for accepting and retaining the gun to be tested, a plurality of baffle plates, each having an aperture therethrough for alignment with a muzzle portion of the gun, a plurality of witness screens for alignment with the gun muzzle portion, a plurality of motion detection sensors for alignment with the apertures of the baffle plates, and a bullet receptacle for alignment with the gun muzzle portion for receiving a bullet fired from the gun. The invention further contemplates a method for testing underwater guns, utilizing the above assembly.

Abstract: A device for use as a muzzle brake for an underwater gun having a project conveying structure with concentric inner and outer cylinders. The inner cylinder has at least one longitudinal slot formed therein. A sealing means joins the projectile conveying structure to the underwater gun at the structure's first end. A second end of the structure is provided with a seal for closing the second end after a projectile is fired through it. A piston having an aperture therethrough is positioned inside the inner cylinder and is axially moveable therein adjacent the longitudinal slot. An actuator is positioned between the inner cylinder and the outer cylinder. Actuator links through the longitudinal slot connect the piston with the actuator. After a projectile is fired through the projectile conveying structure to displace the piston from its initial position, the actuator means returns the piston to that initial position to ready the device for reuse.

Abstract: A projectile testing system and method is used to assess the projectile fht and test the accuracy of a projectile launcher and projectile in both controlled and uncontrolled underwater environments. The projectile testing system includes a penetrable member that is positioned substantially orthogonal to an expected flight path of the projectile. The penetrable member intercepts the projectile, forming a penetration in the penetrable member. The location of the penetration is used to determine the actual flight path of the projectile. The penetrable member further includes side support members that help keep the penetrable member taut. In an underwater environment, flotation members and anchor members are coupled to the penetrable member, to hold or support the penetrable member taut. The projectile testing system can also include multiple penetrable members positioned consecutively to provide a more accurate assessment of the actual flight path of a projectile.

Abstract: A sealing apparatus which may be mounted on multi or single barreled guns disclosed to provide a watertight seal on an underwater gun. The sealing apparatus comprises a sealing plate connected to a gun barrel and a muzzle seal which fit on the muzzle of the gun barrel and frictionally engages the sealing plate. The sealing plate includes a firing aperture which aligns with the gun barrel when the gun is fired.

Abstract: The present invention relates to an underwater weapon having a system for aling the opening of a gun barrel to prevent the ingress of water. The sealing system includes a non-metallic or metallic tape for covering and sealing the opening and a mating surface on the gun barrel against which the tape is seated to prevent the ingress of water. The sealing system further includes sprockets for advancing the tape across the opening of the gun barrel and for maintaining the tape in a taut position during operation.