Abstract: A rupturable bag assembly comprises an inflatable bag which parts at a target internal pressure to produce an acoustic shock wave having a minimum target noise level at a prescribed distance. The inflatable bag comprises inner and outer walls. The inner wall has greater elasticity than the outer wall. Both inner and outer walls are constructed from first and second disk shaped sections with the first and second sections being sealed along outside perimeters. The second section of the inner wall carriers a heat resistant shield on one face. An inflation port assembly provides a chamber for a fuel source and flame abatement elements between the fuel source and an inlet port to the rupturable bag.

Abstract: An acoustic projector includes a toroidal whistle having an annular mouth and a foot set in a bowl like reflector. The reflector extends radially outwardly from the foot and has a concave section circumscribing the annular mouth. A whistle bowl is configured to suppress turbulence in air flow and thereby provide laminar flow to an outlet jet orifice into the annular mouth. The concave section is shaped to reflect isophasic sound generated at the mouth in a coherent beam.

Abstract: A sound system for a locomotive mounts a loudspeaker line array for broadside firing forward from the vehicle. Additional loudspeakers are installed on the locomotive for projecting sound to the sides. A control system applies drive signals to the loudspeakers of the line array with the control system providing phase adjustment of drive signals applied to each loudspeaker of the line array to control side to side directional steering of a projected sound beam. The control system includes an automated, location dependent sub-system for selecting beam width and directional steering of a projected sound beam.

Abstract: A loudspeaker assembly comprises a casing with a diaphragm loudspeaker mounted in the casing. A phase plug is mounted in the casing adjacent the diaphragm loudspeaker. The phase plug has a central cone with a longitudinal axis extending from an input end adjacent the diaphragm loudspeaker to an output end with its base at the input end tapering to an apex at the output end. A plurality of vanes extend radially outwardly from the central cone with the plurality of vanes being thickest at the input end and progressively thinning toward the output end. Radially outward edges of the plurality of vanes are twisted relative to the longitudinal axis with the degree of twist being progressively greater with increasing proximity to the output end. The plurality of vanes tapers in width along their longitudinal extent from the input end to the output end.

Abstract: An electro-dynamic acoustic projector provides a rigid enclosure having an open end. A pressure compensated chamber extends into the rigid enclosure from the open end. A vibratile piston is located in the open end of the rigid enclosure and closed the pressure compensated chamber. The vibratile piston has an axis of oscillation perpendicular to the plane of the open end and an anterior major surface exposed from the open end for generating sound waves in water. A magnet assembly is attached to the vibratile piston which interacts with a stator coil positioned with respect the rigid enclosure and vibratile piston. The magnet assembly is affixed to a posterior surface of the vibratile piston. The magnet assembly comprises first and second permanent magnets located with respect to one another to bring like poles into facing opposition. The facing like poles are separated from one another by a ferromagnetic focus element.

Abstract: A radial waveguide assembly comprises a transducer section and a waveguide section. The transducer section includes first and second cone loudspeakers arranged coaxially and in an opposed relationship. A compression plug having two input surfaces is mounted between diaphragms of the cone loudspeakers. Channels from the first and second cone loudspeakers feed common sound chambers located in a belt around the circular perimeter where they connect to external ports. A radial, folded waveguide has a circular throat which connects to the external ports.

Abstract: A radial waveguide assembly comprises a transducer section and a waveguide section. The transducer section includes first and second cone loudspeakers arranged coaxially and in an opposed relationship. A compression plug having two input surfaces is mounted between diaphragms of the cone loudspeakers. Channels from the first and second cone loudspeakers feed common sound chambers located in a belt around the circular perimeter where they connect to external ports. A radial; folded waveguide has a circular throat which connects to the external ports.

Abstract: An EM energy projector incorporates a final stage radiator including a shaped reflecting spike having a forward radiant axis. The shaped spike defines a set of equivalent, discrete input locations, there being a plurality of such locations. The emitters are arranged in a closed line array, and disposed with all of the emitters oriented inwardly toward the forward radiant axis.

Abstract: A vortex cannon based on pulse detonation engine comprises a combustion chamber, a fuel source, an oxidizer source, a purge gas source, a valve allowing delivery of fuel from the fuel source to the combustion chamber, a valve allowing deliver of either oxidizer or purge gas from the oxidizer and purge gas sources to the combustion chamber, an ignition source for the combustion chamber for initiating detonation of fuel and oxidizer, and a conical barrel outlet from the combustion chamber. The combustion chamber is configured for control over the detonation front. A control system provides for varying the rate and quantity of fuel and oxidizer injected to the combustion chamber for varying the frequency and strength of pulse generation. Ring vortices may be generated either in single pulses or at high rates of fire which maintain a consistent track.

Abstract: Differential spacing of loudspeakers in an end fire array is employed to reduce beam spread and, where a ground barrier is present, to suppress any resultant back wave.

Abstract: A loudspeaker system comprises a plurality of speaker transducer units divided among and arrayed in at least three linear arrays. The linear arrays are disposed in a like plurality of elongated rectangular baffles. The elongated rectangular baffles are disposed in side by side relationship along the respective elongated sides of the baffles in the form of a tube. The speaker transducer units are aligned in a plurality of ranks. The ends of the tube are closed with the result that one side of speaker transducers radiates into the interior of the enclosure and the other side radiates into the environment. The speaker transducers of each rank are spaced no further from one another than one quarter wavelength at a selected frequency.

Abstract: A system for targeting directed acoustic energy comprises a directed acoustic energy source. The system provides for locating a target relative to the location for the directed acoustic energy source and for aiming the directed acoustic energy source relative to the target to account for at least the effects of wind drift on the sound field generated by the directed energy source. Further sources of atmospheric data may include wind direction and speed and temperature, both at surface levels and at altitude and at a plurality of location including the locations of the target, the directed acoustic energy source and intermediate points.

Abstract: A system of remotely locatable sentries or watchtowers operate as part of a network of such sentries or towers for securing a border or perimeter over a wide area. A sensor array, including particularly an array of video cameras, provides for detection, tracking and identification of a target. The sentry or watch towers include non-lethal, sound-based instrumentalities for discouraging entry into and passage through a secured zone of the target.

Abstract: An acoustic radiator for underwater application is provided by opposing boundaries mutually spaced and centered on a common axis, a plurality of radial barriers located perpendicular to and connected between the top and bottom boundaries to define a plurality of adjacent radial waveguides, and a plurality of transducers disposed in each radial waveguide, and with one group of transducers being located radially outwardly from another group, the groups being defined in part by all members of the group being the same distance from the apex of the radial waveguide.

Abstract: An omni-directional acoustic horn for applications in a liquid transmission medium deploys a plurality of transducers distributed along an interior face of the horn to radiate against an opposed surface. The arrangement mimics operation at a greater depth of submergence to depress development of acoustic cavitation bubbles.

Abstract: An EM energy projector incorporates a final stage radiator including a shaped reflecting spike having a forward radiant axis. The shaped spike defines a set of equivalent, discrete input locations, there being a plurality of such locations. The emitters are arranged in a closed line array, and disposed with all of the emitters oriented inwardly toward the forward radiant axis.

Abstract: An electro-dynamic acoustic projector provides a rigid enclosure having an open end. A pressure compensated chamber extends into the rigid enclosure from the open end. A vibratile piston is located in the open end of the rigid enclosure and closed the pressure compensated chamber. The vibratile piston has an axis of oscillation perpendicular to the plane of the open end and an anterior major surface exposed from the open end for generating sound waves in water. A magnet assembly is attached to the vibratile piston which interacts with a stator coil positioned with respect the rigid enclosure and vibratile piston. The magnet assembly is affixed to a posterior surface of the vibratile piston. The magnet assembly comprises first and second permanent magnets located with respect to one another to bring like poles into facing opposition. The facing like poles are separated from one another by a ferromagnetic focus element.

Abstract: A shield having a front major surface and a rear major surface supports a loudspeaker array mounted to the shield to project sound outwardly from the front major surface. A signal source for driving the loudspeaker array is mounted to the rear major surface and supplies signals for recorded auditory warnings or tones to the loudspeaker array. The signal source may include a microphone, a receiver allowing reproduction over the high intensity loudspeaker of broadcast or narrowcast signals from a remote location or a recorded signal playback device. If a recorded signal playback device is provided it may further allow for storage of new or replacement signals.

Abstract: An EM energy projector incorporates a final stage radiator including a shaped reflecting spike having a forward radiant axis. The shaped spike defines a set of equivalent, discrete input locations, there being a plurality of such locations. The emitters are arranged in a closed line array, and disposed with all of the emitters oriented inwardly toward the forward radiant axis.

Abstract: A stun grenade that provides a flash and an associated loud report without use of pyro-ignition sources. The flash is generated by discharge of a conventional flash bulb. The loud, explosive noise comes from rupturing of an inflatable bag at a predetermined rupture pressure and inflation volume.