摘要:
An active control method and apparatus for encouraging the early destruction of trailing vortices formed by a lifting body having at least two control surfaces on each side and creating multiple vortex pairs is provided. The method includes actuating the control surfaces in a manner leading to the direct excitation of one or more of the Transient Growth Mechanism, the Short Wavelength Instability, the Long Wavelength Instability, and the Crow Instability to result in the accelerated breakup of the trailing vortices. A method of selecting control parameters in an active control system includes identifying the near-field vorticity distribution of the aircraft, selecting at least one amplification mechanism for distorting the trailing vortices, determining amplitudes and wavelengths for imposed vortex perturbations, simulating trailing vortex evolutions, determining effectiveness of perturbations and amplification mechanisms, determining vortex positions as a function of control surface deflections, and determining control parameters to govern the movement of the wing control surfaces.
摘要:
A submarine signal launcher is disclosed for preventing pinched control ws therein. The submarine signal launcher includes a gas generator, an acoustic device countermeasure, a launch tube for housing the gas generator and the countermeasure, and a ram plate positioned between the gas generator and the countermeasure. A status cable is connected to the countermeasure and intermediately threaded through the ram plate and joined to the gas generator. A collapsible tube connected to the ram plate and to the gas generator. The status cable is confined within the collapsible tube. Securing members are formed on opposing ends of the collapsible tube for securing the collapsible tube to the ram plate and the gas generator, wherein upon assembly of the gas generator with the ram plate and the countermeasure within the launch tube, the collapsible tube will protect the cable from being pinched between joined ends of the ram plate and the gas generator.
摘要:
Electromagnets are disposed in an elastomeric coating affixed to a body esed to a fluid. Controllable magnetic forces created by the electromagnets produce a wavy-wall configuration in the surface of the coating which may be static, dynamic, or static in part and dynamic in part, and which interfaces with the fluid to controllably alter noise, turbulence and drag characteristics of the body mechanically. Electrodes may be fixed on the surface of the coating to produce electric force fields for interacting with the magnetic fields and the wavy-wall, to produce magnetohydrodynamically generated Lorentz forces which controllably further alter noise, turbulence and drag characteristics of the body.
摘要:
A method and a submarine are disclosed influencing an acoustic source emitting an acoustig signal having a first frequency spectrum with at least one intensity maximum. In order to make detection of the frequency spectrum by means of passive acoustic locating systems more difficult, the first frequency spectrum is stochastically modulated by influencing the acoustic source.
摘要:
A method for operating submerged submarines and a submarine are disclosed which are used to camouflage submerged submarines which, while submerged and travelling, draw a trail of heated cooling water behind themselves. In order to reduce the risk of detection of such submerged submarines by means of heat-sensitive detectors, either the density of the heated cooling water is increased through the introduction of additives, or, the heated cooling water is brought, by mechanical means, to a depth far below the submarine for preventing heated-up cooling water to rise up to the sea surface.
摘要:
A method and an apparatus are disclosed serving to reduce acoustic emission from submerged submarines in which vibrations from moving mechanical elements within an inner region are transmitted to an outer hull via a vibration transmission path. For decoupling the outer hull as completely as possible from the moving mechanical elements, for example periodically moving nuclear reactor control rods, the vibrations are actively damped. Means are provided for ascertaining the motion of the mechanical elements relative to the outer hull and for superimposing upon said motion of counter-motion of opposite direction.
摘要:
Coverings are applied to a surface by means of a member capable of temporarily holding the covering and urging it against the surface with adhesive interposed between the covering and the surface. The covering may be held by the member by means of suction and be urged against the surface by air pressure. The member may be mounted on a first articulated arm whose movement can be controlled by an operator who may be situated on a working platform mounted on a second articulated arm. The covering may be an acoustic tile for application to the surface of a submarine hull.
摘要:
4. An underwater noise generator comprising a thick-walled hollow cylindrl housing, said housing having continuous inner and outer cylindrical surfaces and at least one hollow portion between said inner and outer surfaces; a spindle rotatably mounted within said housing along the longitudinal axis thereof, means for rotating said spindle, and a roller mounted on said spindle and driven thereby in rolling contact with said inner surface of said housing, said roller having a plurality of grooves cut in the exterior surface thereof, whereby sound is produced as said rollers roll on said cylindrical housing.
摘要:
Disclosed is a hull device designed to be reversibly attached to an outer surface of a ferromagnetic structure of a marine or submarine system or vessel. The device includes at least one attachment surface suitable for attaching the device to the structure, and a plurality of permanent magnets arranged in the vicinity of the attachment surface in order to attach the device to the structure.