Abstract: An apparatus for attenuating acoustic resonance generated by flow over a cavity in a surface comprises a plurality of flat flaps proximate to an upstream edge of the cavity. The flaps are disposed in an array spaced in a width direction of the cavity edge, and are oscillated by the flow in two degrees of freedom solely by the flow, independent of an actuation mechanism. Each flap includes a first hinge generally coextensive with the surface for enabling oscillation in a first degree of freedom and a second hinge orthogonal to the first hinge and forming a tab for enabling oscillation in a second degree of freedom. The hinges are constructed with torsional spring constants that provide predetermined oscillation frequencies and magnitudes. The apparatus can include a deployment mechanism for moving each flap between a stowed position wherein it is generally flush with the surface and a deployed position wherein the flap can be oscillated by the flow.

Abstract: A system and method for accurately estimating the fluctuating pressure loads on components, such as steam dryers, within a BWR steam dome using pressure time history measurements made on components of the BWR facility external to the steam dome. The method uses existing sensors to obtain the pressure time histories. An accurate determination of the fluctuating pressure loads within the steam dome may be obtained by modeling and analyzing the steam delivery system external to the steam dome, including all possible acoustic sources, using acoustic circuit methodology and pressure time histories, and then coupling these results, essentially as part of the boundary conditions, to the solutions for Helmholtz equation within the steam dome.

Abstract: A strainer for an emergency core cooling system (ECCS) in a nuclear power plant comprises a perforated strainer element that is immersed in a reservoir of cooling water, which is drawn through the strainer element into the emergency core cooling system. The side of the strainer element in contact with the cooling water has a contoured configuration for disrupting the formation of a flat bed of fibrous material that can trap small particulate material intended to pass through the strainer element. Incorporating this strainer element into an ECCS strainer enables the strainer to be made more compact, because the debris bed need not be spread over an unduly large area to prevent excessive head loss from the debris load in the event of a reactor loss of coolant accident. The strainer also incorporates a modular construction that uses individual strainer disc modules. Each disc module includes a perforated first disc part having a central opening and a perforated second disc part also having a central opening.

Abstract: A compressor or pump employs principles of unsteady delayed stall to enhance the head increase produced by the compressor or pump. Plural airfoil-shaped lifting elements are spaced from each other in a cascade and the fluid is directed into the cascade by a device that varies a parameter of the flow relative to each lifting element in repeating cycles to cause the flow relative to each lifting element to begin to separate from the lifting element and then reattach thereto during each cycle. The cascade can comprise an axial flow impeller with plural impeller blades arranged around a hub capable of rotating on an axis. The device for varying the flow parameter can be a stator with a plurality of stator blades upstream of the impeller, or a second, counter-rotating axial flow impeller. In either case, the parameter is a flow angle at which the flow is directed to the downstream impeller.

Abstract: A method and apparatus for light curing of composite materials in which the radiation required to initiate the curing is delivered via one or more lossy fiber optics. The fiber optics are made lossy by methods such as bending the fiber, weaving the fiber into a mat to create periodic micro-bends, tailoring the thickness of the fiber cladding to allow evanescent wave transmission, or simply removing the cladding at intervals along the fiber. Distribution of the light through out the composite material results in dramatic power and time reductions over traditional light curing methods. Unlike thermal curing of composite materials, there is no need for an auto-clave and hence no limit on the size of the part that may be created. Additional benefits include the possibility of curing at operational temperature and so avoiding thermal stresses.

Abstract: A compressor or pump employs principles of unsteady delayed stall to enhance the head increase produced by the compressor or pump. Plural airfoil-shaped lifting elements are spaced from each other in a cascade and the fluid is directed into the cascade by a device that varies a parameter of the flow relative to each lifting element in repeating cycles to cause the flow relative to each lifting element to begin to separate from the lifting element and then reattach thereto during each cycle. For example, when the invention is applied to an axial flow compressor, the cascade comprises an axial flow impeller with plural impeller blades arranged around a hub capable of rotating on an axis. The device for varying the flow parameter can be a stator with a plurality of stator blades upstream of said impeller, or a second, counter-rotating axial flow impeller. In either case, the parameter is a flow angle at which the flow is directed to the downstream impeller.

Abstract: A propulsor that provides thrust by increasing the velocity of a fluid working medium comprises a rotatable impeller including a plurality of impeller blades spaced from each other, each blade having an airfoil cross-section that provides lift as the fluid working medium travels over it. A stator with plural stator blades directs the fluid working medium into the impeller. The stator blades are arranged to vary a parameter of the flow, such as the flow angle relative to each impeller blade, in repeating cycles in a manner that causes the propulsor to generate a predetermined acoustic signature characterized by predetermined acoustic energy levels in the fluid at given locations spaced from the propulsor. In a preferred form of the propulsor, the flow angle is varied so as to cause the flow relative to each impeller blade to begin to separate and then reattach during each cycle.

Abstract: A method and apparatus for light curing of composite materials in which the radiation required to initiate the curing is delivered via one or more lossy fiber optics. The fiber optics are made lossy by methods such as bending the fiber, weaving the fiber into a mat to create periodic micro-bends, tailoring the thickness of the fiber cladding to allow evanescent wave transmission, or simply removing the cladding at intervals along the fiber. Distribution of the light through out the composite material results in dramatic power and time reductions over traditional light curing methods. Unlike thermal curing of composite materials, there is no need for an auto-clave and hence no limit on the size of the part that may be created. Additional benefits include the possibility of curing at operational temperature and so avoiding thermal stresses.

Abstract: A mechanical actuating device for moving an aerodynamic or hydrodynamic surface includes plural flexure members confined in an elastically deformed condition. The flexure members are movable against the force generated by their elastic deformation to move the device into one of at least three stable positions, in which the device, and therefore the aerodynamic or hydrodynamic surface, are held by the force generated by elastic deformation of the flexure members. Since the flexure members are always elastically deformed, the device “snaps” between discrete, stable positions and is held firmly in each. In another embodiment more flexure members can be used to provide additional stable positions. In one application, the actuating device is used as a trailing edge tab for a helicopter or tiltrotor blade to reduce 1/rev vibrations. The device can be actuated manually or electrically using shape-memory alloy wires to snap the flexure members into their various stable positions.

Abstract: A mechanical actuating device for moving an aerodynamic or hydrodynamic surface includes plural flexure members confined in an elastically deformed condition. The flexure members are movable against the force generated by their elastic deformation to move the device into one of at least three stable positions, in which the device, and therefore the aerodynamic or hydrodynamic surface, are held by the force generated by elastic deformation of the flexure members. Since the flexure members are always elastically deformed, the device “snaps” between discrete, stable positions and is held firmly in each. In another embodiment more flexure members can be used to provide additional stable positions. In one application, the actuating device is used as a trailing edge tab for a helicopter or tiltrotor blade to reduce 1/rev vibrations. The device can be actuated manually or electrically using shape-memory alloy wires to snap the flexure members into their various stable positions.

Abstract: This invention relates to a system and method for reducing the primary vortex wake structure generated by a lifting body mounted on an object moving through a fluid. This is achieved by first, altering the generated initial vortex wake to make it vulnerable to rapid breakup; and, second, producing disturbances to this wake with secondary vortices from auxiliary lifting surfaces, called vortex leveraging tabs, to instigate this breakup. This invention relates to various fields of uses to include vortices generated by any type of lifting body moving through a fluid to include aircraft and watercraft, such as surface vessels and submarines.

Abstract: A powder inhaler comprising:a powder housing for holding a supply of powdered material to be dispensed and a metering plate for holding a metered amount of said powdered material, the metering plate being alternately positionable below said supply of powdered material or within an inhalation conduit, by means of a bi-directional, angle-limited relative rotation about a common central axis;a counter for providing a visual count of the number of doses of said powdered material that have been dispensed or remain to be dispensed in response to the relative rotation, the counter including: a continuous counter ring and a coaxially mounted intermittent counter ring, both rings being mounted on a base in surrounding relation to a retaining post, being rotatable about the common central axis and having counting indicia thereon for displaying said visual count; anda display means through which at least one of the counting indicia is displayed to indicate a count corresponding to a number of doses of powdered material

Abstract: A system for alleviating scouring damage at the base of a structure anchored in the bed of a body of liquid flowing at a velocity relative to the structure, such as a bridge pier in a river bed, comprises a plurality of hollow vehicle tires surrounding the structure in a matrix of plural stacks of tires connected together with their toroidal axes substantially aligned. Each stack comprises a predetermined number of tires so that the top surface of the matrix forms a predetermined angle relative to horizontal.

Abstract: A suction strainer for straining water from the emergency suppression pool of a boiling water reactor includes a plurality of stacked, perforated disks having an internal core with a minimum internal radius r(x) that decreases with increased distance from the intake of the strainer, so that the core has a tapered profile. Internal radius r(x) may vary linearly or exponentially or a combination of both. The stacked, perforated disks each include a first surface that faces in the direction of the intake and a second surface, that faces away from the intake. A circumferential band may connect the first and second surfaces together.

Abstract: A powder dispenser includes a powder housing for holding a supply of powdered material to be dispensed, the powder housing including an inhalation conduit provided displaced relation to the powdered material supply; a metering plate including a metered dose hole for holding a metered amount of the powdered material, and positioned below the powdered material supply, the metering plate and the powder housing being relatively rotatable with respect to each other about a common central axis; a counter providing a visual count of the number of doses of the powdered material that have been dispensed or remain to be dispensed in response to the relative rotation, the counter including counter rings providing the visual count, the counter rings being rotatable about the common central axis and having indicia thereon which display the visual count, and an actuating mechanism rotatable about the central axis for incrementally rotating the counter rings in response to the relative rotation; a nozzle for breaking up agg

Abstract: A self-cleaning, self-propelled strainer designed for installation in boiling water reactor suppression pools. The strainer is designed to prevent strainer clogging and subsequent loss of the emergency core cooling system flow during a postulated design basis loss-of-coolant accident. This self-cleaning strainer is driven by a turbine placed in the strainer flow path. The turbine drives rotation of a brush-and-plow arrangement. The wiping action of the brush and the centrifuging action of the plow remove insulation debris and other particulate matter which might be generated by the LOCA, thereby preventing the strainer from plugging.

Abstract: The present invention features a technique and system for achieving sufficiently stable, thick liquid films on an aircraft surface during a rain storm in flight, wherein such stable and thick films can be measured to determine liquid water content (LWC) in the air, and (by known correlation) rain fall rate. Rainfall impinging upon an airflow surface of an aircraft, such as a wing portion, is gathered and confined within a weir-like structure. The flow of the rain is constricted within this device to increase the film thickness and reduce shear between air and liquid boundaries, whereby a stable film surface for measurement is provided.

Abstract: A drag reducing apparatus is attached to the back of a vehicle and serves to reduce drag by capturing at least two vortices which turn the flow inwardly behind the vehicle body thereby effectively reducing the back area of the vehicle. The first and second vortices are captured in cavities formed by a first and a second vertical panel attached to the back of a vehicle. A third horizontal panel can be attached to the top of the first and second panels to create a cavity for the capture of a third vortex formed by the air stream flowing over the top of the vehicle. The panels are preferably hinged so that they can be folded up flat against the rear of the vehicle when not in use. When in use the panels are locked in position so that they don't vibrate when the vehicle is moving. Top and bottom panels can be employed to define the upper and lower limits of the first and second vortex. Other embodiments employ different panel arrangements to improve the efficiency of the vortex capture.