Abstract: A gas turbine engine airfoil assembly for damping airfoil vibrations includes a metallic airfoil having an outer surface and a chordwise extending cavity beneath the outer surface of the airfoil. A damper is trapped within the cavity and a region in the airfoil surrounding the cavity has compressive residual stresses imparted by laser shock peening. The damper is preferably a chordwise extending linear wire having a distal end tacked down within the cavity. The invention includes a method for constructing the assembly for damping airfoil vibrations.

Abstract: A turbine blade which is provided for use in a wet steam region of penultimate and ultimate stages of turbines and is subject to erosive wear caused by impinging water droplets, is treated in a region of leading edges and parts of a blade leaf in such a way as to reduce the erosive wear. In order to reduce the erosive effect of the water droplets, the blade leaf has a surface roughness in the region of its leading edge and its blade back or in at least a partial region thereof. The surface roughness is markedly increased in comparison with the surface roughness of a front side of the blade leaf.

Abstract: A wind driven electrical power generating apparatus includes an armature. The apparatus also includes a wing secured to the armature. The wing defines a pocket having a hub end and an outer end. The width of the pocket monotonically increases from the hub end to the outer end. Moreover, the depth of the pocket monotonically increases from the hub end to the outer end. The wing and the armature produce a relatively large amount of torque during rotation of the armature which is converted to high rotational speed by a gear mechanism thereby driving a generator at a relatively high rotational speed. Such high torque production eliminates the need to rotate the armature at a high rotational speed. Moreover, the configuration of the wing allows the armature to be rotated in the presence of relatively low wind velocities. Hence, the apparatus may be efficiently utilized for electrical power generation in geographic areas which typically experience relatively low wind velocities.

Abstract: A turbo-machine comprises a housing. The housing has internal surfaces which come into contact with fluid flowing through the turbo-machine. The surfaces have an ordered, fine, sharp-edged groove structure that is affixed to the surfaces, such that the groove structure extends predominantly in the flow direction.

Abstract: A sail system for wind turbines of the vertical shaft type is disclosed. The sail system has a vertical rotating shaft, a plurality of support arms radially extending from an upper portion of the rotating shaft, and a sail pivoted to the tip of each support arm. The sail is provided with a longitudinal horizontal slit and is eccentrically pivoted to the tip of each support arm by means of a hinge. A holding rod is pivoted to an outside portion of the arm and penetrates the longitudinal slit of the sail. A spring is fitted over the holding rod between the spring stopper of the holding rod and the outer surface of the sail. The sail system not only prevents the sail from sagging due to the sail's weight, it also tightly pivots the sail to the arm regardless of the sail's configurations. The maximum turning angle of the sail relative to the arm is limited and adjusted by the spring.

Abstract: A rotary turbine employs rotors that are rotated primarily by the frictional forces of a pressurized medium flowing through a gap that separates the rotors from the stationary housing. The rotors are coupled to a source of pressurized medium that creates a medium flow through the gap. The frictional forces between the flowing medium and the rotors create a torque that rotates the rotors. A compressor is formed of a rotor assembly that includes first and second counter-rotating rotors having substantially smooth surfaces. The rotors are separated by a gap that allows the medium to flow therethrough, with the surface of at least one of the rotors contacting the medium, such that the flow of the medium through the gap is induced by surface friction between the contact surface and the medium.

Abstract: A rotor-stator assembly includes a rotor and a stator, each of which has a plurality of teeth wherein the height of the teeth is less than approximately one twentieth the diameter of the rotor-stator. According to a presently preferred embodiment of the invention, the height of the teeth on the rotor-stator is approximately 1/48th the diameter of the rotor-stator. A twelve inch diameter rotor-stator having teeth 1/4" high can be rotated at 3600 rpm with 40 HP when mixing materials with water-like viscosity. The arrangement of the teeth on the rotor-stator is preferably concentric with radial grooves, but angled grooves may also be used. The teeth my have a triangular or square profile and the dimensions of the teeth, other than their height, may vary considerably.

Abstract: A cast and hot isostatically pressed gamma titanium aluminide turbine blade has an aerofoil portion including a concave pressure surface and a convex suction surface. The concave pressure surface has surface irregularities, produced by the action of the hot isostatic pressing process on voids located within the cast turbine blade, located in that region of the concave pressure surface where in operation aerodynamic separation occurs to minimise the aerodynamic effects of the surface irregularities upon the operation of the turbine blade. The remaining portion of the concave pressure surface and the whole of the convex suction surface are substantially free of surface irregularities.

Abstract: The present invention provides a propeller fan having a blade trailing edge of a sawtooth shape, in which the flows on the negative pressure side and the pressure side of a blade join gradually, so that the velocity loss is decreased in the vicinity of the trailing edge. As a result, the velocity gradient decreases and the generation of turbulence is reduced as compared with the conventional propeller fan, so that the noise is reduced and the fan efficiency is enhanced.

Abstract: In order to reduce the noise nuisance caused during operation by rotor blades of a rotor of a wind turbine the rear edge of each blade is irregularly formed. In particular the saw-tooth form with a top angle smaller than about 150.degree. and preferably 10.degree. is found to produce a considerable noise reduction.

Abstract: A rotary turbine including a source of a pressurized medium and a rotor assembly. In one embodiment, the rotor assembly includes first and second rotors, and the surface of each rotor is substantially smooth. The pressurized medium flows between the rotors, turning the rotors. The smooth rotor surfaces do not cause substantial turbulence in the medium. Accordingly, the exit velocity of the pressurized medium is maintained at a substantial higher level than if the rotors included blades or other protrusions extending outwardly.

Abstract: A rotary blade includes a fixed boundary layer control device extending spanwise on a lower surface adjacent the trailing edge to improve the lift/thrust characteristics of the blade especially at positive incidence angles. It was discovered that expected detrimental effects at zero/negative incidence did not materialize and the reasons are identified. Such blades are particularly useful for helicopter sustaining and anti-torque rotors.

Abstract: A blade for use in an axial fan includes a plurality of vanes which each have a winglet formed on their front face to increase the air flow of the fan at a given blade velocity.

Abstract: A fan blade for a ceiling fan is formed as an elongated laminated plate body which includes several layers of thin wooden plates that are bonded together. The laminated plate body has a top face which is formed with projecting strips and a bottom face which is formed with recessed strips that correspond to the projecting strips.

Abstract: A gas turbine engine hot section component such as a turbine blade or vane having an airfoil is provided a non-film cooled portion of a heat transfer wall having a hot surface and a plurality of longitudinally extending micro-grooves disposed in the portion of the wall along the hot surface in a direction parallel to the direction of the hot gas flow. The depth of the micro-grooves is very small and on the order of magnitude of a predetermined laminar sublayer of a turbulent boundary layer. The grooves are sized so as to alter the boundary layer thickness near the leading edge of the airfoil to reduce heat transfer from the hot gas flow to the airfoil near the leading edge. In one embodiment the micro-grooves are about 0.001 inches deep and have a preferred depth range of from about 0.001 inches to 0.005 inches and which are square, rectangular, or triangular in cross-section and the micro-grooves are spaced about one width apart.

Abstract: An air fan includes a plurality of fan blades each fan blade drilled with a plurality of perforations in the fan blade for reducing weight of each fan blade for reducing the electric energy required for driving the fan motor of the air fan. Each fan blade may be reinforced by at least a rib on a surface of each fan blade for enhancing its strength and preventing its deformation.

Abstract: A centrifugal impeller includes a hub formed about an axis of rotation with a plurality of substantially radially extending blades affixed to the hub, each blade having a suction surface, and a pressure surface formed on the adjacent blade facing the suction surface. The blades have a height being measured in a radial direction from the hub. A portion of the hub, having a hub configuration, extends between the pressure surface and the suction surface. An imaginary plane extending in a direction normal to the axis of rotation is used to define a cross-sectional view of the impeller. A first and a second concentric circle are formed in the plane with the center of the concentric circles being the axis of rotation. The first circle passes through a point on the hub located closest to the axis of rotation. The second circle has a radius greater than the first circle by an amount equal to five percent of the blade height, wherein a portion of the hub extends outside of the second circle.

Abstract: Flow separation behind the notch region of a swept tip of a helicopter rotor blade is reduced by a plurality of boundary layer control vanes located adjacent a forwardly swept leading edge portion forming the notch region.

Abstract: A polyurethane impeller for mixing liquids lasts considerably longer than equivalent metal impellers of the prior art. The impeller comprises a disk having inner and outer portions of polyurethane resin having different flexibilities, the outer portion being bonded to the inner portion and having greater flexibility than the inner portion. The polyurethane portions are chemically reacted with each other to form a strong chemical bond.A method is provided for centrifugally casting a polyurethane impeller having inner and outer sections of different flexibility and hardness.

Abstract: An axial-flow fan-blade, with at least one profiled guide fin extending from the surface of each blade of the fan-blade, is able to control flow direction of the fluid and keep fluid flow speed stable; and, furthermore, offsets the centrifugal force (which is caused by rotation of the blade) with the centripetal force that is generated by pressure difference of the fluid flowing across both sides of each profiled guide fin. The fan blade minimizes turbulent flow, reduces noise generated by vibration of the blades, and increases rigidity of the blades.

Abstract: A blade (14) for a centrifugal flow fan (11) having forward curved blades. The blade has a boundary layer trip (21) on its pressure surface (14). The trip promotes the transition of the boundary layer from laminar to turbulent flow and enables the layer to remain attached to the pressure surface for a greater distance. The increased amount of attached flow enables greater fan efficiency and reduces fan radiated noise. The boundary layer trip may be of a variety of configurations.

Abstract: A high speed mixing apparatus is shown for slurry materials which includes a stationary housing and a cylindrical rotor mounted for rotation within the housing. The rotor has an outer surface which is embossed with a repeating pattern of pyramidal shapes, each pyramidal shape having four triangular faces which meet at an apex. Each face has a base edge which forms grooves in the rotor for directing the flow of slurry in directions 45 degrees relative to the rotor's axis of rotation.

Abstract: A vertical axis wind turbine blade comprising a blade body with a leading edge and trailing edge there between being generally parallel to each other with a series of a given intersecting triangulation of troughs along the enire blade length with each trough so intersecting transversally the trailing edge and being a upwardly given taper in direction of the leading edge by approximately 80 percent of the blade width and therewithal each trough is formed into a wind channelling containment of equispaced troughs there upon being adjacent with each other along the blade length and with the trough width therein respectively changing the wind driven air columns for a maximum transferring of energy to the blades on the windward side by a higher pressure building up while going into the troughs, while there about on the opposite side there is a reversal type of effect being cause by a pressure drop across the troughs by a lowering of air pressure flows into the troughs to therein cause an effect of speeding up the v

Abstract: A marine propeller (4) has a plurality of blades (12, 13, 14, and 15) each with an integral addendum (34) extending rearwardly from the trailing edge (30) of the positive pressure surface (26) of the blade. A particular combination of blade area ratio and blade rake is provided to enable quick acceleration to a high-speed on-plane condition in blade surfacing racing applications, and without bobbing up and down. The blade area ratio is at least 40%, and the blade rake is 10.degree. to 25.degree..

Abstract: Each blade of a low speed propeller fan extended radially outwardly from a member connected a rotating body has a coarsened surface at least part of its suction side. The coarsened surface has a coarsened density or depth which gradually increases from the front edge of the blade to its rear edge.

Abstract: Each blade of a high speed propeller fan extended radially outwardly from a member connected to a rotating body has a coarsened surface at least part of its suction side. The coarsened surface has a coarsened density or depth which gradually increases from the rear edge of the blade to its front edge.

Abstract: An airfoil has a plurality of spaced apart, U-shaped troughs in either or both its suction or pressure surface in the trailing edge region. Each trough extends in a direction generally parallel to the bulk fluid flow in its vicinity near the airfoil surface and has an outlet at the trailing edge. The troughs increase in depth from their inlets toward their outlets, the maximum depth being no more than half the trailing edge thickness. The troughs are spaced apart, sized and configured to flow full over their entire length and to cause fluid to flow into the space immediately behind the trailing edge, thereby reducing base drag.

Abstract: The invention pertains to a fan blade and a method for making a fan blade wherein the stresses within the blade material are substantially constant throughout the length of the blade and the unique construction of the blade reduces the concentration of loading on the blade material. Preferably, the blade is molded of a synthetic plastic material and includes a ribbed structure locating material offset from the concave convex configuration of the blade air flow portion such that the section modulus of blade sections from the air flow portion toward the root portion increases by increasing the distance of the blade material from the neutral bending axis in such a manner that no abrupt changes occur and the stresses imposed upon the blade material throughout its length are substantially constant.

Abstract: In turbomachine apparatus having alternating rows of stator blades and rotor blades, there is provided discontinuities or nonuniformities on the downstream facing surfaces of at least one row of stator blades, the nonuniformities being adapted to disperse pressure waves reflected from downstream rotor blades. The nonuniformities may be an arrangement of grooves, ridges, or a combination of grooves and ridges on the downstream facing blade surfaces; other surface discontinuity configurations are also possible, such as an arrangement of potruding surface elements or dimples, or force-absorbing material selectively deposited on the dowstream-facing portion of the blade surfaces.

Abstract: Wind turbine blades for use e.g. in generating electricity are described in which the blades have fixed lift spoilers in the form of deep spars projecting on the normally high pressure side of the blades where they are relatively ineffective, but which, in down-wind operation of the turbine, are on the low pressure side which generates (but for the spars) substantially all the lift and are therefore very effective. Active spoilers are also disclosed on the low pressure side of the blade rapidly deployable to control an overspeed condition. The whole is controlled by a computer to maintain desirably constant tip speed ratio, the variable rotor speed being converted hydraulically or electrically to constant frequency current, or to maintain a constant turbine speed to generate constant frequency current with overspeed protection.

Abstract: In a centrifugal fan having radially directed fan blades, each having, in combination, a serrated surface forming in longitudinal cross-section a sawtooth configuration in the radial direction of the rotating blade with a wear resistant coating over a substantial area of the serrated surface.

Abstract: A turbine wheel for a low-speed, single-stage turbine is constructed with a large number of blades which extend radially outward in planes normal to the axis of rotation of the wheel, each blade having a relatively sharp leading edge and a thicker body portion which merges smoothly with the leading edge. In the preferred construction each blade in transverse cross-section is diamond shaped and is arranged with two of its opposite sharp edges forming the leading and trailing edges of the blade.

Abstract: A windmill is disclosed, the windmill including a vertical shaft mounted for rotation about its longitudinal axis, a number of blades spaced circumferentially around the longitudinal axis, and being disposed generally parallel to the axis of rotation of the vertical shaft, and supporting arms extending radially outwardly from the vertical shaft for supporting the blades. The windmill also includes a first member connected to an upper end of one of the blades and defining a first surface having a leading edge with respect to the direction of movement of the blade and a trailing edge rearward of the leading edge, the leading edge being lower than the trailing edge. The first surface also includes an inside lateral edge and an outer lateral edge spaced radially outwardly from the inside lateral edge, the inside lateral edge being higher than the outer lateral edge.

Abstract: A disc-like impeller for dispersing solids within liquids is formed of ultra-high molecular weight polyethylene with a plurality of radially extending grooves on each planar face to provide a long wearing product with excellent mixing results.

Abstract: A method of making a sheet metal fan blade having a flattened mounting pad. The blade is to be attached to a flat spider arm of a fan hub. According to the method, a fan blade blank workpiece of cylindrical stock and of any desired outline (such as rectangular, trapezoidal, etc.) is simultaneously provided with a longitudinally running rib and a flat pad portion by stamping. In this manner, the outline of the blade is not distorted by stamping the cylindrical blank to form the flat mounting pad.

Abstract: An improved radiator cooling fan has a substantially planar mounting hub and individually twisted blades extending radially therefrom. Each blade includes reinforcing edges along a portion thereof to enhance durability and lengthen useful service life.

Abstract: A propeller fan construction is provided in which the impeller thereof includes a spider member having a plurality of symmetrically arranged planar marginal portions, and a plurality of blades projecting outwardly from the spider member. Each blade has an inner end provided with a planar segment which is fixedly mounted on a planar marginal portion of the spider member. The spider member and each of the blades are formed of sheet material. Each blade is provided with an elongated embossment extending from one elongated edge of the blade in an angular direction relative to the longitudinal axis of the blade. The embossment is position between the outer end of the blade and the planar segment of the inner end.