Abstract: A rotor system for horizontal-axis wind turbines is provided having compound coning and a sweep angle to improve the rotor system's yaw responsiveness and stability and to reduce vibration and stress. To further improve wind turbine performance and rotor durability blades with the load-bearing function and airfoil function separated are disclosed and are particularly useful in rotor systems having compound coning or compound coning and sweepback. The load-bearing function and support function of the rotor hub are separated to improve rotor system durability and to provide a rotor hub for use with a pitch change mechanism for altering the pitch of rotor system blades.

Abstract: An improved airfoil blade for aircraft propellers and the like which exhibits high aerodynamic performance and low far and near field noise levels at a minimum weight is provided with a novel high lift and high lift to drag cross-sectional airfoil shape characterized by a blunt, generally parabolic leading edge portion (10) which fairs into a pressure surface (15) characterized by a leading convex portion (20). For thickness ratios less than approximately 0.15, the pressure surface includes a concave trailing portion (25) at one end thereof, fairing into the leading convex portion (20) and at the other end thereof, terminating at a blunt trailing edge (35). The leading edge portion also fairs into a suction surface (30) which is convex along substantially the entire length thereof to the blade trailing edge.

Abstract: A stirring device attached to the vertical shaft of a sand mill having an annular metal collar received on the shaft and a flat, plastic, circular disc extending radially beyond the collar for a stirrer member concentrically affixed to the radial surface of the collar. The stirrer member has an outer ring and a central hub which are joined by circumferentially spaced spokes.

Abstract: According to the present invention, there is provided a turbomachine rotor assembly having a blade mounting means comprising a rotor spool defining a flowpath surface and having at least one circumferential dovetail shaped retaining groove therein. A plurality of radially extending blade members each comprising a dovetail root are positioned in the retaining groove of the rotor spool. The root comprises a pair of axially oppositely extending asymmetric shoulders having radially outwardly facing and differentially radially spaced contact surfaces for mating with complementary surfaces of the retaining groove of the rotor spool.

Abstract: A propeller comprises a first elongate, non-twisted part (1) of streamlined cross-section and of constant cross-sectional area and constant shape from one end of said part to its other, and a second, planar part (2) which connects with one longitudinally extending edge of the first part and which is of constant thickness and breadth. The second part (2) has a surface (5) which merges at least substantially tangentially with one, convex single-curve surface (3) of the first part, and a surface 6 which merges smoothly with the other surface (4) of the first part (1).

Abstract: The invention relates to a blade end for rotary wing of an aircraft, whose span is between 5 and 15% of the span of said blade. According to the invention, this blade end is charaterized in that, between points A and B', there is a stagger which, measured parallel to the span of the blade, is between 5 and 25% of the chord of the profile of the blade adjacent said blade end and in that the leading edge line of said blade end is curvilinear and such that its angle of sweep .phi. varies progressively and continuously from a low value .phi..sub.o near the blade, of between 0.degree. and 30.degree., up to a high value .phi..sub.E towards the outside of the blade, of between 60.degree. and 90.degree.. The invention leads to increased performances and to a reduction in the noise level of rotary wings.

Abstract: A helicopter rotor blade is disclosed having a root end for attachment to a rotor head, a tip end defining the end of the blade fartherest from the root end with a central portion of aerofoil section extending between and attached to the root end and the tip end to define a rotor radius wherein an outboard region of the central portion has a negative basic pitching moment coefficient of absolute value not less than 0.02 and an inboard region having a basic pitching moment coefficient more positive than that of the outboard region.

Abstract: Six rows of radial blades, arranged to extend in a spiral (in the direction of axial rotation) covering 55 degrees of arc about a hollow support section, constitute an optimum blade arrangement for maximum efficiency in low velocity airflows. Each blade in the rows is contoured to receive both direct flow pressure as well as airfoil lift in order to provide maximum energy transfers from low velocity airflows.

Abstract: Supersonic rotor blading in an axial-flow fan or compressor employs blades such that shock waves originating on a blade are canceled at the intersection of the wave and the surface of an adjacent blade by virtue of a blade configuration such that the shocks intersect the blade surface at a line of properly oriented change in flow angle of the blade surface. A three-wave system is employed.

Abstract: A wind turbine blade of large size for a wind turbine (14) having three blades (16) and used to generate electrical power is contoured to minimize stalling and to provide unusually good efficiency. The cross section of the blade tapers from a configuration at the hub or inboard end with substantial leading and trailing edge deflection toward the wind providing high lift at low speed, to the outboard one-fourth to one-fifth which is configured as a conventional low lift airfoil since it moves through the air at comparatively high speed. The chord length of approximately the inboard one-third of the blade is chosen such that, in combination with the deflection, very little air is permitted to cross this inboard part of the blade but is forced to flow radially outwardly such that by reason of an increase in dynamic pressure it augments the flow across the faster moving part of the blade.

Abstract: A windmill blade system with two distinct blade ends with each comprising a center area having a series of identical projections equidistant from a central mounting orifice in the center area. Each of the projections consist of an upward and a downward facing triangle sharing a common base. When the blade units are combined by aligning the center areas of each, the triangles of the upper blade unit are above the plane formed by the center areas and the lower triangles of the lower base units are below that plane. With the lower blade unit projections forming a mirror image of the upper ones.The invention also contemplates a windmill having at least one of the blade systems rotating horizontally about a vertical shaft.

Abstract: A marine ring propeller comprising blades, each having parallel edges and a constant cross-section, and a ring in the form of an annular shroud fixed to the outer ends of the blades. The shroud is typically frusto-conical on its inner surface and curved on its outer surface to provide an aerofoil cross-section, apart from the leading edge which is provided with a concave bevel on either or both of the inner and outer surfaces.

Abstract: A cross flow fan (10) imparts both radial and axial flow components to airflow passing through the fan, resulting in a conical exit airflow. The fan includes a hub (12) and circumferentially spaced, radially extending fan blades (14, 16, 18, 20, 22, and 24). Backing plate portion (34, 36, 38, 40, 42, and 44) is associated with each of the blades 14-24. The backing plate portions lie on a conical plane which rakes backwardly from the hub in a direction downstream from the fan. The fan blades are disposed in a plane oblique to their corresponding backing plate portions, so that they intersect the latter along a joining edge (50). Each of the fan blades includes portions having greater (56) and lesser (58) radii of curvature. The portions (58) of lesser radii of curvature cooperate with the corresponding backing plate portions (36) to provide a radial component to the flow through the fan whereas the leading edge portions (56) provide the axial flow component.

Abstract: A windpower generator which includes a cupped blade design to be assembled from flat module sheets together with a resiliently biased mount to provide automatic feathering with a consequent speed control. A generator or alternating generator to feed electric output to an existing power system, as, for example, a residence or small business establishment, is associated with the windmill to serve as a counterbalance in the mounting and to cooperate with the self-governing blade assembly. A switching circuit is connected to feed generator power to the local utility power lines when net power is available at the winddriven alternator and in phase with utility power.

Abstract: A family of airfoils for use in rotary wing aircraft, particularly helicopters, is disclosed. The family is characterized by having a maximum c.sub.1.sbsb.max at M=0.4 and maximum delay in drag divergence while maintaining zero lift pitching moment levels c.sub.m.sbsb.o correctable within the range of -0.01 to +0.01. The present family of airfoils provide high lift at maximum angle of attack when the blade is retreating and maximum delay in drag rise or drag divergence when the blade is advancing. The airfoil section of the family enable a helicopter rotor to counteract, more efficiently, the rolling moment which would otherwise be induced by a rotorcraft's forward flight; this is achieved by the present family of airfoils while maintaining the airfoil sectional pitching moment coefficient at or about zero thereby enabling the blade in which the airfoil sections are incorporated to impose minimum structural loads on the rotorcraft's control system.

Abstract: A propeller blade for a multi-bladed propeller comprises a radial inner pion, a radially outer portion and a transition portion extending therebetween. Generally, the leading edge of the blade portions are colinear and the trailing edges of the inner and outer blade portions are offset from each other so that shoulders are defined on the transition portion and the outer blade portion has a higher blade angle of attack than the inner blade portion. The shoulders extend from the leading edge to the trailing edge of the transition for providing flow stability and blade reinforcement.

Abstract: An airfoil blade tip is so configured that, when it is caused to rub against a surrounding casing, the resultant force acting on the blade tip is substantially in the tangential direction. In this way, axial forces on the airfoil are substantially reduced.

Abstract: Windmill apparatus comprises an open framework defining a wheel having means defining a pivot axis and embodying a plurality of radially and closely spaced concentric rows of air foils. The foils in each row are connected for their conjoint movement to and from a pre-set operating position, within defined limits. The movement of each foil is about an axis which is substantially radial to the wheel and it is arranged to automatically feather when subject to impact of winds the speed of which is at a dangerous level. As oriented in the wheel the radial extremities of each foil are substantially flat and bridged by a continuous peripheral surface portion. One portion of said peripheral surface portion is flatted to define the operating face of the foil. The flatted portion is preferably comprised of two planar surface portions one of which leads the other, having regard for the facing of the foil operating surface into the prevailing wind.

Abstract: Propeller and fan blading comprised of an extruded airfoil having a rib retained at the root for mounting and with a portion thereof removed by flattening the back of the blade truncating the back camber thereof in a plane tapered toward the blade tip with respect to the front camber thereof and having a flap of full configuration toward the root of the blade and continuing tangent from the front camber and extending angularly back from the back camber and reduced toward the blade tip by profiling the trailing edge made thin toward said tip by a flattening truncating the back trailing portion of the blade toward said tip, the said blading being controllably pitched and feathered by a hub having cylinder and piston means responsive to engine oil pressure and rotating the blades on their radial axes to a full pitch position by link and lever means biased toward a feathered position by an adjustor means having adjustable stops and means for maintaining moderate pitch until the engine is stopped.

Abstract: A propeller or impeller construction having a plurality of blades mounted on a hub section. The blades are essentially triangular in cross section and are hollow to achieve light-weight and permit center air flow. In addition, the blades may be tapered in such manner that accelerated internal air movement with compression toward the tip ends is enabled. The tip portions of the blades may be vented to provide for air flow through the center and out of the tips, and also the rear structural plate may be vented to the low pressure side of the blades. Blade construction may provide for variations in the pitch angle. The blades are mounted on the hub section by a unique construction which may provide both commonality and interchangeability of parts. This construction also enables the use of shims to facilitate balancing and to change and/or adjust thrust characteristics without changing blades.

Abstract: A blade for windmills fabricated of sheet metal to form a generally hollow structure containing a reinforcing member. The surfaces of the blade are such that the forward surface is flat and rear of the blade is formed by two surfaces which extend in opposite directions from a line extending from a radially inner point at a rearward side of the pitch axis of the blade to a point at the radial outer end and forward of the pitch axis of the blade.

Abstract: A mechanical aerator comprising a boss, and at least one blade which extends radially from the boss and comprises a planar body portion and a deflector, the arrangement being such that when the aerator is mounted for rotation about a vertical axis the planar body portion of the blade lies in a vertical, or substantially vertical, plane and the deflector is inclined circumferentially upwardly from the top of the planar body portion.

Abstract: An improved nozzle for use in a cooling tower comprises a connecting member defining an orifice and a spinner rotably mounted on the connecting member so that liquid passing out of the orifice impinges on and thereby rotates the spinner. The spinner defines a plurality of arms projecting from a central section, each arm being spaced from adjacent arms by grooves or slots. The trailing edges of at least some of the arms are inclined at an angle of 10.degree. to 25.degree. with respect to the travel direction of liquid passing out of the orifice. With this construction, liquid to be cooled can be sprayed into the cooling tower in the form of a substantially uniform pattern of very fine droplets.

Abstract: A moving blade row of high peripheral speed for thermal axial flow turbo machines, especially for the last stage of condensing steam turbines, the blades of which, when viewed in a radial direction, have their middle and outer regions located in the range of transonic flow. The blade section in the middle range or in the middle and outer regions starting from the trailing edge is formed by two straight lines. The straight line at the suction surface side joins the steadily curved curve of the remaining suction surface side without any distinctive bend, whereas the straight line at the pressure surface side near the trailing edge of the blade joins the steadily curved curve of the remaining pressure surface side with a distinctive bend or discontinuity.

Abstract: A helicopter rotor blade includes a rearwardly swept tip portion having a leading edge of aerofoil profile located forward of the leading edge of a central portion of the blade, and blended with a sharp tip edge of higher sweep magnitude than the leading edge and extending rearwardly to an extreme tip of the blade. A rearwardly swept trailing edge extends from a junction with the trailing edge of the central portion to the extreme tip so that the tip portion has a chord dimension greater than that of the central portion of the blade.In operation, the rotor blade utilizes a stable vortex dominated flow field created over the tip portion to provide operational advantages in respect of both a retreating and an advancing blade.

Abstract: Lightweight gypsum wallboard produced by continuously combining a small amount of surface active agent with a liquid stream which stream is made up of substantially all of the liquids to be used in the manufacture of a continuous web of gypsum wallboard, subjecting this mixture to an intense agitation with vaned saw tooth-like rotary blades in a foam generator while adding a controlled quantity of air thereto, forming a uniformly dispersed foam of very small bubbles from the liquid by completely generating all of the surface active agent therein to form this foam, and mixing this foamed liquid with finely ground dry calcined gypsum in a suitable mixing device to form a foamed settable gypsum slurry, disposing the slurry between paper cover sheets, and forming a continuous web of gypsum wallboard.

Abstract: The present device is a rotor having a plurality of rotor chambers formed integral therewith. Each chamber has an inlet opening into a main section, whose sidewalls are substantially parallel, and further has a nozzle section whose sidewalls deviate at an angle from the main section sidewalls to create a sharp cross-sectional constriction and which nozzle section ends in an outlet opening. The present rotor is used as the single rotor of a turbine engine which has means to initiate a shock wave at the opening of the main section of each rotor chamber. The rotor chamber is formed to direct the shock wave uninhibited toward said outlet opening but said shock wave is reflected from said sharp cross-sectional constriction toward said inlet opening thereby compressing the gases in said chamber to a high pressure. In each chamber when said high pressure gases expand through said nozzle section the ensuing reaction drives said rotor.