Abstract: An axial flow fan comprising a printed circuit board which mounts the circuitry for operating the motor which is a bipolar winding motor. A voltage regulator IC and a driving IC for a bipolar winding motor are mounted on the printed circuit board. The fan housing is employed as a heat sink for the voltage regulator. Large circuit elements are eliminated. The axial flow fan further comprises a plurality of blades for cooling electronic components wherein the blades comprise of a plurality of specially designed airfoil sections, each section having along substantially the entire length thereof, a cross-sectional shape characterized by a maximum thickness located substantially constantly between about 19% chord to about 20% chord and a maximum camber located substantially constantly between about 45% chord to about 46% chord. The circuitry, housing, and blades are designed so that the axial width of the axial fan is decreased while maintaining performance parameters and design constraints.

Abstract: In an axial fan having a plurality of blades (2, 2, . . . ) around an outer periphery of a hub (1), a cross-sectional configuration of each of the blades (2) at an arbitrary distance from a center of the fan is set such that a blade thickness gradually increases moving away from a blade leading edge (2a) and then gradually decreases towards a blade trailing edge (2b). Also, if a length of a camber line extending from the blade leading edge (2a) to a position where the blade thickness becomes maximum is taken to be L, and a length of a camber line extending from the blade leading edge (2a) to the blade trailing edge (2b) at the arbitrary distance is taken to be L.sub.0, then L/L.sub.0 falls within a range of 0.27 to 0.35. Thus, the aerodynamic performance never lowers even if the inflow angle of air into the blade (2) varies.

Abstract: The present invention provides a fan (100) that includes a hub (102) and a plurality of blades (104). The hub (102) has a blade attachment surface (106) that extends around the circumference of the hub (102). The blades (104) extend from the blade attachment surface (106). Each of the blades (104) has a blade tip (108) distal from the blade attachment surface (106) and a chord length (110) defined as the width of the blade (104). Each blade (104) includes a hub chord length (112) defined as the chord length of the blade (104) at the blade attachment surface (106) and a tip chord length defined as the chord length at the blade tip (108). The relationship of the chord length to the blade radius is defined as the area bounded by the following equations:blade radius=0.0205 metersblade radius=0.0369 meterschord length=0.438*(blade radius)+0.021 mchord length=0.438*(blade radius)+0.028 m,and the blade angle is defined as the area bounded by the following equations:blade radius=0.0205 metersblade radius=0.

Abstract: A high aspect ratio, low solidity fan blade of an axial flow air cycle machine has a local tip center of gravity axis that has been shifted ahead of an elastic axis. The center of gravity axis can be shifted by clipping the tip of the blade at the trailing edge, by undercutting a rear portion of the pressure surface, or by sweeping forward leading and trailing edges of the blade by about five degrees (without clipping or undercutting the blade).

Abstract: The coordinates defining the upper surface, lower surface, leading edge configuration and center of circle for a helicopter blade airfoil are given to increase maximum lift coefficient and lift-to-drag ratio, and to reduce noise level.

Abstract: In a helicopter blade aerofoil, upper and lower surfaces thereof are defined by the following coordinates, and the leading edge profile of the aerofoil is defined by the following leading edge radius and center of circle. Thus drag divergence Mach number Mdd and maximum lift coefficient Clmax can be increased and the level of noise can be reduced.______________________________________ X/C Yup/C Ylow/C ______________________________________ 0.00000 0.00000 0.00000 0.00250 0.00781 -0.00558 0.00500 0.01131 -0.00765 0.00750 0.01423 -0.00874 0.01000 0.01660 -0.00964 0.01750 0.02224 -0.01156 0.02500 0.02658 -0.01276 0.50000 0.03585 -0.01568 0.07500 0.04128 -0.01758 0.10000 0.04480 -0.01901 0.15000 0.04893 -0.02113 0.20000 0.05095 -0.02306 0.25000 0.05181 -0.02492 0.30000 0.05200 -0.02647 0.35000 0.05179 -0.02760 0.40000 0.05129 -0.02821 0.45000 0.05038 -0.02827 0.50000 0.04888 -0.02775 0.55000 0.04673 -0.02662 0.60000 0.04393 -0.02491 0.65000 0.04037 -0.02268 0.70000 0.03592 -0.01996 0.75000 0.03052 -0.01682 0.

Abstract: An airfoiled blade for improving the performance of a propeller at low aircraft speeds and for maintaining good performance of the propeller at high aircraft speeds is disclosed. The blade comprises a root portion for connection to a hub of the propeller and a tip portion defining an opposite end of the root portion. An elongated portion extends between the base portion and the tip portion and defines a leading edge and a trailing edge. The elongated portion has a cross-section defined by a scaleable airfoil section. The scaleable airfoil section comprises a chord having a fifty-percent chord station, a forward end defining the leading edge of the blade and an aft end defining the trailing edge. The airfoil section is aft end loaded for developing aft end lift. The scaleable airfoil section also has a camber distribution and a thickness distribution based therefrom.

Abstract: A jet airplane capable of supersonic flight has airfoils with leading edges. Each leading edge has a cavity which extends for substantially the entire length of the airfoil. The leading edge also has a cover which is approximately the same size as the cavity. The cover has an open position and a closed position. When the cover is in the open position, the leading portion has a concave profile. When the cover is in the closed position, the leading portion has a convex profile that gives the airfoil a conventional shape. The cover is rotated to the open position when the airplane reaches supersonic speed. At supersonic speed, a shock wave forms on the leading edge of the airfoil. However, the cavity forms a compression zone between the shock wave and the leading edge, diverting the heat and pressure of the shock wave away from the airfoil. Downstream from the compressed zone, pressure wakes form along the airfoil and cool the airfoil.

Abstract: An airfoiled blade is disclosed which comprises a plurality of airfoil sections, a root portion, and a tip portion. Each section has along substantially the entire length thereof a cross-sectional airfoil shape characterized by a parabolic leading edge, a front loading and a blunt trailing edge. Each of the airfoil sections has a chord passing therethrough with a 50% point and a maximum thickness forward of the 50% point, toward the leading edge. A thickness ratio range from a first of the airfoil sections nearest the tip portion to a last of the airfoil sections nearest the root portion of substantially 3% to 28% is preferred. In one embodiment, the blade further includes a second airfoil section, a third airfoil section and a fourth airfoil section located between the first and last airfoil sections. The first airfoil section has a thickness ratio of substantially 3.3%, the second airfoil section has a thickness ratio of substantially 4.1%, the airfoil section has a thickness ratio of substantially 7.

Abstract: A structure of a ventilation fan provided with a plurality of blades has a performance curve characterized by a gentle slope throughout the wide operating range instead of an S-hysteresis curve, in order to overcome a fluctuation phenomena of the operating flow rate. The blade tip cross-section lies on a first imaginary cylindrical surface and an angle of attack and pitch angle of the blade tip are formed as respective trajections by intersecting the first cylindrical surface by a second cylindrical surface whose center axis has been rotated about two axes.

Abstract: A turbine device and a method of driving the turbine device are disclosed. The turbine device includes an admission channel, a turbine, and an injection channel. The turbine device may also include a regulator. The turbine is driven by injecting a primary fluid into the admission channel at a given velocity and simultaneously causing a secondary fluid to flow into the admission channel at a lower velocity. The primary fluid and the secondary fluid form a mixture in the admission channel, which flows toward the turbine. The velocity of the mixture is less than that of the primary fluid, while the mass flow of the mixture is approximately equal to the sum of the mass flows of the primary and secondary fluids. The regulator compares the rotational speed of the turbine to a target speed and regulates parameters associated with the turbine device if the rotational speed of the turbine and the target speed differ by more than a predetermined amount.

Abstract: An axial flow compressor for use in a gas turbine or other industrial application having an improved efficiency is provided through modification of the blade shape and profile of the blades subject to a subsonic high velocity inlet flow so as to avoid shock losses in the blade rows, and improve the total efficiency. The curvature distribution on the suction surface of the stator blade rows or rotor blade rows of the axial flow compressor is adapted to have a local minimum in a region toward the leading edge of the blade, and then a local maximum. Thereby, an excessive increment in velocity on the suction surface from the leading edge to the position of the maximum velocity can be suppressed, and the occurrence of a shock wave can be avoided so as to minimize pressure loss in the blade rows, thus increasing the total efficiency of the axial compressor.

Abstract: A ceiling fan blade includes a peripheral portion having two side portions and an end portion. The side portions and the end portion each includes either a concave surface or a tapered surface for decreasing a resistance to the relative wind to the ceiling fan blade and for facilitating the air circulating effect of the ceiling fan blade.

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 high output fan assembly for cooling the radiator of a motor vehicle. The fan assembly comprises a shaft, first and second fans, and a motor. The first fan includes a plurality of first blades, each of which has an inner portion attached to the shaft, while an outer hub is attached to an outer portion of at least one of the first blades. The second fan includes a plurality of second blades, each of which has an inner portion attached to the outer hub. The motor is drivingly connected to the shaft to drive the first and second fans at the same number of revolutions per minute. The fan assembly is situated either for pulling or for pushing air across the radiator and an air conditioning condenser of the motor vehicle.

Abstract: A high solidity impeller has a number of equally spaced blades, each formed from a sheet that is bent to a continuous cylindrical curve along a roll axis that lags (in the rotation direction) the radius at which the blade is attached to the shaft. The blade also is pitched by rotation around the radius, i.e., the leading edge is raised in the flow direction and the trailing edge is lowered. The roll axis preferably lags the radius by 45.degree.. This arrangement provides a good approximation of a true hydrofoil and results in an excellent reconciliation between interests of material and manufacturing cost vs. pumping efficiency. The blades can be formed by rolling asymmetrically shaped contours cut from a flat sheet. A base member and preferably a connecting arm couple each blade to the shaft. The base member abuts the rolled contour along surfaces referenced to the roll axis, which surfaces can be used as a reference for rolling.

Abstract: Liquid mixing impellers particularly designed for the chemical processing industry provide a generally axial flow when rotated in a first direction of rotation and provide a generally radial flow when rotated in the opposite direction of rotation. The blades are formed of sheet material with an edge which leads in the first direction of rotation being defined by a portion of the blade which is folded and turned in a chordwise sense through a limited extent back upon itself. The folded back leading edge forms a rearwardly facing concavity which faces the blade trailing edge. The power number in the radial flow rotation direction substantially exceeds the power number in the axial flow rotation direction.

Abstract: An axial flow fan device capable of reducing the stagnant flow at the root area of blades. These blades 18 are arranged so that they extend radially from a boss portion 14 so that they are circumferentially spaced along the circumference of the boss portion 14. Each of the blades 18 has an arc shaped cross section having a bending ratio value .alpha., that is a ratio of the bending height h of the arc shape to the length l of the chord of the arc shape. The value of the bending ratio rapidly increases from the middle portion of the blade to the root portion. The value of the bending ratio at the root portion is about 12%.

Abstract: A scrap melter apparatus which includes a drive motor disposed above a molten metal bath, and a shaft attached to a bottom of the drive motor, and protrudes partway into the molten metal bath. A scrap melter impeller is attached to the bottom of the shaft. The impeller is a rectangular block of refractory metal, having a flat upper surface and a formed lower surface. The formed lower surface includes a first area disposed in a central portion of the metal block which has an even thickness from a first side of the impeller to a second side of the impeller. A second area is adjacent to the first area, and is tapered from a thin section at the first side of the metal block to a thick section at the second side of the metal block. The thickness of the second area at the second side corresponds to the thickness of the central area. A third area is adjacent to and on an opposite side of the first area from the second area.

Abstract: A hydrofoil impeller includes three impeller blades attached to a hub. Each impeller blade includes a flat section and a curved section which terminates in a tip portion. The flat section has a root portion proximate the hub and which forms a predetermined root angle with respect to a plane perpendicular to the vertical axis of the impeller. The curved section is separated from the flat portion by a bend line. The curved section is bent downwardly from the plane of the flat section along the bend line. The bend line is oriented with respect to the impeller blade such that the blade tip angle is changed as the bend is formed. Accordingly, the bend is used to set the proper tip angle. The blade angle increases from the tip inward to the bend line, then becomes a constant where attached to the hub. The camber increase from the tip inward to the bend line, then falls to zero where attached to the hub.

Abstract: An agitator assembly for use in effecting dispersion of a fluid such as a gas in a liquid comprises a rotor having a rotatably driven shaft 18 mounting a series of scoop-shaped blades 20 which are oriented with the mouths 21 of the scoops presented in the direction of rotation of the shaft, each blade being mounted at an angle of attack such that one end of the blade leads the other in the direction of rotation. To eliminate gas cavity formation, each blade is of generally streamlined configuration in section and the ends 30 thereof are generally transverse to the axis of rotation of the rotor.

Abstract: A marine propeller (100) combines progressive pitch with both increasing pitch and increasing progressiveness of pitch along at least a portion of increasing radii from the axis of rotation to the outer blade tip. A five blade propeller is provided which accommodates thermal warpage of the outer blade tips, such that the same propeller includes two different types of blades, one blade having increasing pitch with increasing radii all the way to the outer blade tip, and the other type of blade having increasing pitch to a given radius and then decreasing pitch with increasing radii to the outer blade tip. The latter blade type is preferred and has a hump in the pressure surface at the noted given radius between portions of increasing and decreasing pitch with increasing radii.

Abstract: A marine propeller includes a hub rotatable about a longitudinal axis and having a plurality of blades extending radially outwardly therefrom and pivotable about respective radial pivot axes between a low pitch position and a high pitch position. Each blade has a hydrodynamic force characteristic which shifts the location of the resultant hydrodynamic force on the blade in a direction aiding up-pitching of the blade, and increasing the up-pitching pivot moment with decreasing angles of attack. A counteractive hydrodynamic force generating area is provided on the negative pressure backside surface of the blade and shifts the location of the resultant hydrodynamic force on the frontside surface forwardly with decreasing angle of attack.

Abstract: Exercising machine having a vaned fanwheel rotatably mounted on a frame in open air and arranged to absorb energy by rotating the vane blades against ambient air. The fanwheel comprises a hub with a plurality of air vanes which are movable in an orbit around the axis of the hub. Each vane comprises a blade having leading and trailing surfaces. In the preferred example shown, each blade is a semi-cylindrical plate mounted with the hollow, concave side comprising the leading surface, and the streamlined, convex side comprising the trailing surface. The vanes are circumferentially spaced apart to substantially eliminate drafting and stagnant wake regions between blades. The coefficient of drag for the concavo/convex vane blades of this invention are substantially twice that obtained by flat plate vane blades conventionally used. Alternative forms of the invention are illustrated with semi-spherical concavo/convex and semi-cylindrical plano/convex blades. All have in common trailing streamlined convex surfaces.

Abstract: A helicoper rotor blade includes at its outer end a tip vane having a mean chord length greater than fifty percent of a chord length of a blade central portion and a span length greater than fifty percent of the blade chord which in operation generates two approximately equal strength tip vortices to reduce an acoustic impulse and a resulting noise known as blade slap.

Abstract: The turbine agitator assembly including a reservoir for liquid, a rotor mounted in the reservoir and with a plurality of radially extending blades, and sparger means for introducing a fluid into liquid in the reservoir. The fluid sparger means and the rotor are so constructed and arranged that, in use, the rotor blades (submerged in the liquid) and/or the liquid flow they generate disperse the sparged fluid. Each of the blades is hollow and has a discontinuous leading edge, only a single trailing edge along an acute angle, no external concave surface and an open radially outer end.

Abstract: A propeller blade element which virtually eliminates stall conditions. The rotatably driven blade element employs a long straight extended sharp leading edge from hub to tip, without helix, to insure blade laminar fluid flow without vortice formation or leading edge stagnation. The extending leading edge provides separated upper and lower laminar air flow to a "C" shaped blade configuration. The blade element in one form employs a proportionally upwardly curved trailing edge which provides accelerated flow of the high pressure air on the face of the blade, thus increasing the thrust over conventional blade elements.

Abstract: An airfoil having a suction surface and a pressure surface, the surfaces joined together at leading and trailing portions of the airfoil, the pressure surface converging toward the suction surface at a corner, the surface converging at the corner by an angle approximately equal to or greater than at least 30.degree., such that an air stream flowing from the leading edge and over the pressure surface separates from the pressure surface at the corner. The fan therefore has a thick nose section and is substantially thinner over the majority of its chord length. One or more guide ribs extend from the pressure surface to control the flow of boundary layer air.

Abstract: A propeller assembly for mounting on the drive shaft of a motorized water vehicle. The propeller consists of a central hub having a hollow body of circular cross-sectional shape through which exhaust gas from the motor can flow. Integrally formed with the hub are a number of arcuate blades. Each blade has a generally fish-shaped axial cross-sectional shape. In particular, from the leading edge of the blade, the cross-sectional shape increases in thickness until reaching a local maximum at a point near the midchord of the blade and thereafter decreases in thickness until reaching a local minimum. The blade thereafter again increases in thickness along concave surfaces until terminating in a concave trailing edge. The trailing edge of the blades are in communication with the exhaust gas flowing through the hub.

Abstract: Impellers and impeller systems are described which enable liquids and liquid suspensions to be mixed and blended where the size of the impeller and the viscosity of the liquid may require operation in the turbulent and laminar flow regimes, as well as in the transitional flow regime therebetween. The impellers have a plurality of fluidfoil blades and have camber and twist. The geometric pitch or blade angle increases from the tip of the blade towards their axis of rotation in a manner to provide an over pitched condition so that the pitch ratio of the blades at 40% of the blade radius from the axis is greater than the pitch ratio at the tip. The blades are preferably smoothly tapered and increased in width from the tip towards the axis. The impeller blades are mounted on a hub connected to a drive shaft. The blades may decrease in width where they connect to the hub. The pitch angle at the tip is in the range of 18.degree. to 30.degree. (preferably about 20.degree.).

Abstract: A marine propeller (100) combines progressive pitch with both increasing pitch and increasing progressiveness of pitch along at least a portion of increasing radii from the axis of rotation to the outer blade tip. A five blade propeller is provided which accommodates thermal warpage of the outer blade tips, such that the same propeller includes two different types of blades, one blade having increasing pitch with increasing radii all the way to the outer blade tip, and the other type of blade having increasing pitch to a given radius and then decreasing pitch with increasing radii to the outer blade tip. The latter blade type is preferred and has a hump in the pressure surface at the noted given radius between portions of increasing and decreasing pitch with increasing radii.

Abstract: A "fish-shaped" hydrofoil section and in particular, a hydrofoil section having a body of cross-sectional area increasing in thickness from the leading edge to a point near the midchord of the hydrofoil section. The thickness of the body then decreasing some amount to a local minimum, and thereafter increasing along concave surfaces in a "fishtail" flare to a local maximum thickness at the trailing edge. A low pressure area develops behind the trailing edge of the "fishtail" flare and is ventilated with gas at a pressure greater than that of the developed low pressure area. The cross-sectional shape of the hydrofoil section can be symmetrical or cambered.

Abstract: Improved turbine comprising plural turbine blades supported by a turbine rotor of a flow meter, each turbine blade having a rounded leading edge, a feathered trailing edge, a concave top blade surface and a convex bottom blade surface, the turbine blade tapered from the leading edge to the trailing edge to form a hydrofoil shaped defined by empirical profile data.

Abstract: A propellor (10) for watercraft has a hub (11) with a pair of blades (12) with a leading portion (13) central portion (14) and trailing portion (15). The leading portion (13) of the blades are forwardly inclined relative to the hub (11) and the blades progress through the generally radial central portion (14) to the rearwardly inclined trailing portion (15), the radial height of the blades decreasing from the central portion (14) to the trailing portion (15). Both the peripheral pitch of the blades (12), and the pitch of the line of junction (16) of the blades (12) to the hub (11) increase along the propellor (10), at least from the central portion (14) to the trailing portion (15).

Abstract: The disclosure is directed to a mixed flow impeller with a low noise, to be used for a blower of an air conditioner or the like. The mixed flow impeller of the present invention is characterized in three points, i.e., thin thickness blade member increased in its thickness only at its leading edge, a plate-like triangular protrusion provided at an outer peripheral portion of the leading edge, and blade curvature line having its maximum curvature position deviated toward the trailing edge side through employment of a cubic curve. Since each of the above features may be caused to function independently, noise reduction is possible even if it is executed singly, but the maximum effect is available when the are effected in combination.

Abstract: A marine propeller (4) combines decreasing overall pitch from hub (6) to blade tip (20) and increasing progressiveness of pitch with increasing radii from hub to tip, and provides uniform loading from hub to tip. The balde has a maximum transverse dimension (36, 46, 48) between the high pressure surface (16) of the blade and a straight line chord (34, 34a, 34b) between the leading edge (22) and the trailing edge (24) of the blade. The ratio of this maximum transverse dimension to the length of the chord is ever increasing from hub to tip. A parabolic blade rake along the maximum radial dimension line (50) of the blade is provided in combination.

Abstract: A rotating impeller for stirring liquids contained in tanks. Strip-like blades of simple form radiate from a central hub, in swept-back configuration relative to the direction of rotation. The blades are angled relative to the hub so as to exert a forward and downward force upon the liquid as the impeller rotates, and the blade curvature is such that the area projected upon the liquid by the solid structure of the rotating blade is less than the corresponding area that would be projected by an otherwise similar blade in which imaginary straight lines connected all adjacent vertices, and any void areas lying within the boundaries of those imaginary lines had been filled in. The preferred arrangement of the blades is such that when the impeller is arranged with its axis vertical, curvature of each blade along its length is such that it extends away from the hub in a diminishing downward curve, reaches a lowest point, and then rises again before the blade tip is reached.

Abstract: Turbo-machine blade, including: a continuously curved profile contour having convex curved leading edge, suction side and trailing edge regions, and a concave curved pressure side region; the leading edge section being formed of a first ellipse section and a second ellipse section adjacent the first ellipse section;the suction side region being formed of a first circle section adjacent the second ellipse section and a first parabola section of a first second-order parabola being adjacent the first circle section; the trailing edge region being formed of a second circle section adjacent the first parabola section; and the pressure side region being formed of a third circle section adjacent the first ellipse section and a second parabola section of a second second-order parabola being disposed between the second circle section and the third circle section.

Abstract: The mean line (F) of each blade (1) is formed by a flat continuous curve contained in a plane OZ-OY.sub.o forming with the plane of rotation of the propeller an angle .phi..sub.o between 35.degree. and 55.degree. and preferably between 40.degree. and 50.degree., said curve having a first part of negative Y.sub.o and positive Z coordinates, and a second part of positive Y.sub.o and positive Z coordinates, the coordinate point Y.sub.o =0 being situated between the values of Z included between 0.75 and 0.85 R (R designating the radius of the propeller), the tangent to this curve has its end corresponding to the end of the blade forming with the axis Oz an angle between 30.degree. and 50.degree. and preferably between 35.degree. and 45.degree..

Abstract: A multi-bladed marine propeller designed for efficient operation in intermediate, partially cavitating flow regions between fully cavitating flow and noncavitating flow. Each of the blades has a radially inner subcavitating section and an outer section which is configured to have a higher angle of attack and tapered trailing and leading edges so that it supercavitates at high speeds either with or without ventilation and subcavitates at low speeds. Various other features of each blade include different length chords on the pressure and suction sides of the outer section and an inclined trailing surface area extending between the chord ends for improved off design, design point, and astern operation. A minimized transition area is included between the inner and outer sections, and narrow chord lengths are provided in the tip area to minimize and balance overall tip section drag.

Abstract: An impeller apparatus for dispersing a gas into a liquid in a vessel includes a centrifugal flow turbine, the blades (621) of which are formed with a substantially stream-lined trailing surface terminated by a sharply pronounced spine (63). The blade is formed by a plate-like initial blank being cut to a shape having a central line of symmetry, the blank then being folded along the straight line of symmetry.

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: A mixing blade assembly including a hub, a set of impeller blades having air foil configurations and flat end portions for attachment to corresponding flat surfaces of mounting members which attach the blades to the hub. The flat attachment surfaces avoid stresses tending to distort the blades. The hub is a hollow member made from a set of plates. The leading edges of the blades are generally straight, and the trailing edges are inclined rearwardly from the tips towards the roots of the blades.

Abstract: Turbo-machine blade with a profile contour having a convex leading edge region, a convex suction side region, a convex trailing edge region and a concavely curved pressure side region, including profile segments being blended into each other forming the profile contour and following each other in a continuous curve, the profile segments including:(a) a first ellipse segment and a second ellipse segment adjacent to the first ellipse segment in the leading edge region,(b) a first circle segment adjacent to the second ellipse segment and a second order parabola segment adjacent to the first circle segment in the suction side region,(c) a second circle segment adjacent to the parabola segment in the trailing edge region, and(d) a third circle segment adjacent to the second circle segment and the first ellipse segment in the pressure side region.

Abstract: Airfoil for vehicle fan which operates in low Reynolds number and varying turbulent conditions having a discontinuity formed on the suction surface thereof adjacent to its leading edge to trigger early formation of a laminar flow bubble so that sufficient suction surface remains downstream of the air bubble whereby air circumventing the bubble can reattach to the suction surface for sufficient pressure recovery for high lift and low drag performance.

Abstract: A propeller (10) including a hub (12) and a plurality of blades (16) having a leading edge (22), outside edge (24), tail edge (26) and inside edge (28). Each of the blades (16) extend substantially radially from the hub (12) and include a body portion having a regressive pitch from the leading edge (22) to the tail edge (26) and cupped portions (30) and (32) extending along the inside edge (28) and outside edge (24), respectively. A method of making the propeller (10) includes the steps of forming the hub (12) and forming the plurality of blades (16) having a regressive pitch and extending substantially radially from the hub and forming the first cupped portion (30) extending along the inside edge (28) and the second cupped portion (32) extending along the outside edge (24).

Abstract: An improved propeller blade configuration that permits a relatively strong configuration without reducing the cavitation thickness or efficiency of the blade. This is achieved by providing a planar section on the front face of the blade that merges into a recessed cup shaped portion and by having the rearwardmost axial portion of the rear face lie in an axial direction contiguous to the point of merger.

Abstract: The mixing of liquid and liquid suspensions in vessels is obtained by a mixing impeller mounted on a shaft and rotated by a drive which delivers selected speed and torque. The torque and power needed to obtain given flow is minimized by a low-cost impeller having a plurality of blades, each formed from a plate of constant thickness except for a leading edge of rounded profile. Each blade has camber which decreases from the tip to the base thereof. The base can be flat to facilitate the attachment of the blades to the shaft. The blades are oriented and twisted to be at the threshold for flow separation along the width of the blades from the leading to the trailing edge thereof, thereby providing maximum flow in the axial direction before the onset of flow separation.

Abstract: A wooden wind turbine blade is formed by laminating wood veneer in a compression mold having the exact curvature needed for one side of the blade, following which the other side of the blade is ground flat along its length but twisted with respect to the blade axis.

Abstract: A rotating impeller for stirring liquids contained in tanks. Strip-like blades of simple form radiate from a central hub, in swept-back configuration relative to the direction of rotation. The blades are angled relative to the hub so as to exert a forward and downward force upon the liquid as the impeller rotates, and the blade curvature is such that the area projected upon the liquid by the solid structure of the rotating blade is less than the corresponding area that would be projected by an otherwise similar blade in which imaginary straight lines connected all adjacent vertices, and any void areas lying within the boundaries of those imaginary lines had been filled in. The preferred arrangement of the blades is such that when the impeller is arranged with its axis vertical, curvature of each blade along its length is such that it extends away from the hub in a diminishing downward curve, reaches a lowest point, and then rises again before the blade tip is reached.