Abstract: A novel concept for a propeller blade configuration incorporates the model of the natural wave behavior. The leading edge of the propeller blade is parallel to the trailing edge, but offset by a given amplitude. The surfaces between the leading and trailing edges are rounded so as to promote proper fluid sheet formation along the surface and to reduce undesirable vortice formation. Best results are obtained by modeling the surfaces along a sine or tangent function.

Abstract: Upper and lower surfaces of an aerofoil are defined by the following coordinates given in the table below, and the configuration of a leading edge of the aerofoil is defined by the following leading edge radius and the center of circle. Thus drag divergence Mach number Mdd and maximum lift coefficient Clmax can be increased and the noise level can be reduced.______________________________________ X/C Yup/C Ylow/C ______________________________________ 0.00000 -0.00323 -0.00323 0.00100 0.00155 -0.00758 0.00250 0.00418 -0.00925 0.00500 0.00782 -0.01062 0.00750 0.01060 -0.01155 0.01000 0.01312 -0.01213 0.01750 0.01912 -0.01316 0.02500 0.02381 -0.01388 0.05000 0.03437 -0.01561 0.75000 0.04070 -0.01707 0.10000 0.04466 -0.01852 0.15000 0.04893 -0.02100 0.20000 0.05083 -0.02312 0.25000 0.05150 -0.02506 0.30000 0.05149 -0.02663 0.35000 0.05105 -0.02775 0.40000 0.05016 -0.02835 0.45000 0.04875 -0.02839 0.50000 0.04663 -0.02767 0.55000 0.04359 -0.02618 0.60000 0.03974 -0.02407 0.65000 0.03515 -0.02146 0.70000 0.

Abstract: A pump impeller of a centrifugal- or a half axial type meant to pump liquids, mainly sewage water, the pump impeller including a hub provided with one or several vanes, the leading edges of which being strongly swept backwards. The size of the sweep angle (.alpha.) varies between 40 and 55 degrees at the connection with the hub, and 60 and 75 degrees at the periphery.

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: A bi-directional fan includes asymmetrically-shaped fan blades wherein, at each transverse cross-section of the blade, the profile of the blade includes a leading portion lying on one side of a straight line connecting the leading and trailing edges of the blade and a trailing portion lying on the opposite side of the straight line. The leading portion of the blade is larger than the trailing portion of the blade, and the point at which the blade's mean line of profile crosses the straight line is closer to the trailing edge than the leading edge. From the leading edge to a point of maximum camber, the shape of the profile of the blade is described by a polynomial expression. From the point of maximum camber to the trailing edge, the shape of the profile of the blade is described by a cosine wave function. The larger leading portion presents a greater forward-curved surface area which allows the blade to move air more efficiently in the forward direction.

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 turbine pump impeller provided with vanes of the double-curvature type, obtained monolithically by die casting and comprising, between two disk-shaped elements, a plurality of double-curvature vanes. In each vane, the two surfaces that are struck by the fluid are obtained from a sequence of transverse curved portions formed by circular arcs centered on a common spatial central axis.

Abstract: A swept fan blade design for the low pressure compressor rotor or fan rotor stage of a ducted fan gas turbine engine has a leading edge swept forward near the hub up to a first radial height, then rearward up to second radial height and finally is swept forward again up to the blade tip. The aerodynamic effect is to produce a mid-height bias to the airflow enabling the tip region to be given increased twist and to possess increased resistance to foreign object damage. The design also provides a rear radial blade stacking axis to help reduce internal stresses due to centrifugal forces.

Abstract: Airfoils for the tip and mid-span regions of a wind turbine blade have upper surface and lower surface shapes and contours between a leading edge and a trailing edge that minimize roughness effects of the airfoil and provide maximum lift coefficients that are largely insensitive to roughness effects. The airfoil in one embodiment is shaped and contoured to have a thickness in a range of about fourteen to seventeen percent, a Reynolds number in a range of about 1,500,000 to 2,000,000, and a maximum lift coefficient in a range of about 1.4 to 1.5. In another embodiment, the airfoil is shaped and contoured to have a thickness in a range of about fourteen percent to sixteen percent, a Reynolds number in a range of about 1,500,000 to 3,000,000, and a maximum lift coefficient in a range of about 0.7 to 1.5. Another embodiment of the airfoil is shaped and contoured to have a Reynolds in a range of about 1,500,000 to 4,000,000, and a maximum lift coefficient in a range of about 1.0 to 1.5.

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: An axial fan for a cooling blower of a vehicle engine has fins with leading and trailing edges, and aeroacoustic optimization is provided by each of the leading edges and trailing edges having a strong forward sweep followed by a strong backward sweep in the manner of a bird's wing or by a straight forward sweeps followed by a strong backward sweep.

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: A mixing process may be carried out in a tank of a certain diameter. The process may also be constrained to the use of an impeller of certain diameter in order to obtain the flow pattern desired to carry out the process. The power consumption of the system which may be expressed in terms of flow per unit (Q/P) is optimized for the impeller diameter to tank diameter (D/T) constraint by utilizing an axial flow blade, preferably having camber and a tip chord angle at the tip and an angle near the attachment to the shaft (the hub) which rotates the impeller, where the tip chord angle and the twist the difference between the blade angle (between the chord and a plane perpendicular to the axis of rotation of the shaft between the tip and hub) are varied in opposite senses; for example, increasing the tip chord angle to provide a more D/T for a more optimum Q/P to which the process is constrained and then reducing the twist to maintain the power efficiency at the higher tip chord angle.

Abstract: A rotor (18) for use with a fluid flow generator or reactor, the rotor being intended to rotate about a central axis (19) and having a surface which defines an arcuate fluid pathway for fluid flow about the central axis about which the rotor is able to rotate, wherein the surface has the configuration of a logarithmic curve substantially conforming to the mathematical progression known as the Golden Section or the Fibonacci Progression.

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: An impeller for a radial flow device selected from the group consisting of radial--and mixed-flow compressors, pumps and turbines which is designed for both aerodynamic performance and manufacturability at high production rates. The mean blade surface of the impeller is substantially helical, as the angle of any point on the mean blade surface relative to a meridional plane passing through the axis of rotation of the impeller varies linearly with the radius and z-axis location of that point relative to an arbitrary radial plane z.sub.0. A single-piece mold for making the impeller, and a method for making the mold, are also disclosed. The impeller can made in a high-speed molding process without significant post-production processing, and it can be easily withdrawn from a mold without destruction or disassembly of the mold.

Abstract: A centrifugal ventilator fan having a base plate with an axis of rotation, an inlet ring having an opening therethrough and a plurality of generally flat blades, each having first and second side edges, a leading edge and a trailing edge is provided. Each blade is connected to the base plate along the first side edge, and is connected to the inlet ring along the second side edge. The blades are radially spaced about the axis of rotation and are backwardly inclined with respect to a direction of rotation of the fan. A portion of each blade adjacent to the leading edge has a radius of curvature such that the blade portion adjacent to the leading edge extends generally inwardly towards the axis of rotation to reduce noise generated by the ventilator fan.

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 centrifugal seal assembly for a pump, including a pump casing having a pump chamber, a pump impeller, an impeller passageway and a rotatable pump impeller shaft, the seal assembly comprising a rotatable main body disposed within a seal chamber and attached to the pump shaft, a plurality of circumferentially spaced apart vanes on one side of the main body, each vane including a curved leading edge portion, the vanes being configured such that R.sub.v /D.sub.eo is in the range from 0.3 to 0.7, where R.sub.v equals the curvature of the leading edge of the vanes and D.sub.eo equals the outer diameter of the vanes.

Abstract: A hollow airfoil (10) for a gas turbine engine having a leading edge (12), a trailing edge (14), a pressure side (20), and a suction side (22) includes a plurality of internal spanwise stiffening ribs (31-35) that are arranged in a logarithmic pattern. The particular arrangement of internal fibs (31-35) optimizes stiffness of the airfoil (10) without significantly increasing the weight thereof.

Abstract: This invention relates to a method to dertermine the shape of a fan blade of a sirocco fan which can improve fan efficiency and reduce the noise from flow, comprising the steps of determinating a camber line and, upper surface and lower surface of the blade by equations which define mean line and thickness distribution of NACA wing sections, respectively and determinating maximum ordinate of the camber line by following equation;Ta=2m/pwhere, Ta is leading edge angle,m is maximum ordinate of mean line and,p is chordwise position of maximum ordinate.

Abstract: Airfoils for the blade of a wind turbine wherein each airfoil is characterized by a thickness in a range from 16%-24% and a maximum lift coefficient designed to be largely insensitive to roughness effects. The airfoils include a family of airfoils for a blade 15 to 25 meters in length, a family of airfoils for a blade 1 to 5 meters in length, and a family of airfoils for a blade 5 to 10 meters in length.

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 Savonius rotor assembly includes two blades. Each of the blades has an outer edge and an inner edge with the outer edges of the blades lying on a circle which define the diameter of the rotor. Each of the blades has a linear portion adjacent to the inner edge and a first curved portion which is substantially an arc of a circle tangent to the linear portion and tangent to the circle defining the rotor diameter. A second curved portion is substantially coincident to the circle defining the rotor diameter.

Abstract: A thick airfoil for the root region of the blade of a wind turbine. The airfoil has a thickness in a range from 24%-26% and a Reynolds number in a range from 1,000,000 to 1,800,000. The airfoil has a maximum lift coefficient of 1.4-1.6 that has minimum sensitivity to roughness effects.

Abstract: A fan comprises a hub rotatable about a central axis and a plurality of blades each having a root region secured to the hub and extending radially outwardly to a tip region. Each blade is designed with particular characteristics to reduce noise without affecting the performance of the fan.

Abstract: A last-stage steam turbine bucket having a profile according to the charts set forth in the specification.

Abstract: The present invention relates to a device to compress a multiphase fluid such as petroleum effluent comprising a liquid phase and a gaseous phase and a method to use the device. The device comprises a housing (1), an impeller having an inlet section and an outlet section. The impeller comprises an axisymmetric hub (28) with an axis Ox and a number n of blades rotating around the axis. The blades have a leading edge (C1, C2) and a trailing edge (C'1, C'2). The fluid enters the impeller va the inlet section (41) and leaves via the outlet section (42). The axis is orientated in the direction of advance of the fluid. The number of rotating blades (29, 30) is equal to or greater than 2. At least one channel or passage is defined by two successive blades (29, 30) whose orthoradial section S(x) is of the form, within 5% and preferably within less than 3%:S(x)=ax.sup.2 +b(c-x.sup.2).sup.1/2 +don at least one portion of its length.

Abstract: The fan blades have a particular geometry that combines high efficiency, low axial profile, and low noise in an axial flow fan. The fan also comprises a circular outer band that coacts with a surrounding shroud structure to form a labyrinth air seal. The shroud structure comprises two parts that cooperatively define a radially inwardly open groove within which a flange of the fan band is received to form the labyrinth seal.

Abstract: A last-stage steam turbine bucket having a profile according to Charts I-XXXXI of Table I.The bucket is divided into a number of profile sections each of which is a predetermined radial distance from the root section. Each point on a profile section at the predetermined radial distance from the root is defined by an X-Y coordinate and a radius R along the arc of a circle connecting adjacent points.

Abstract: A high performance steam turbine vane having a novel airfoil shape. The pressure surface of the airfoil has a substantially straight region proximate the trailing edge that provides the airfoil with adequate thickness to prevent distortion during forging. The novel shape on the suction surface is such that a first region of the suction surface downstream of the gauging point is essentially straight. Traveling in the upstream direction, the first region is followed by a second region that has a large amount of curvature. The second region is followed by a third region that has a lower curvature than the second region. The third region is followed by a fourth region of constantly increasing curvature that increases to a curvature greater than the curvature of the second region. The fourth region is followed by a fifth region, ending at the leading edge, of essentially constant large curvature that includes the maximum curvature throughout the suction surface.

Abstract: A last-stage steam turbine bucket having an actual and theoretical profile according to Charts II-XVI. The last-stage turbine bucket has a theoretical profile according to Charts I-XVII.

Abstract: A last-stage steam turbine bucket having a profile according to Charts II-XIII, XV-XXVII and XXIX of Table I.

Abstract: A combination solar and wind powered generator including a wind generator, responsive to the flow of air currents, for converting mechanical energy into electrical energy. The wind generator includes a plurality of air spirally shaped engaging vanes which are rotatably supported by the wind generator, and operative for intercepting the flow of air currents for producing mechanical energy. The wind generator also includes an electric generator apparatus coupled to the plurality of air engaging vanes, for transforming the mechanical energy into a first source of electrical energy. A plurality of light sensitive cells, disposed proximate the spirally formed air engaging vanes, are adapted for transforming light energy into a second source of electrical energy. The spirally shaped air engaging vanes may include a plurality of surface deviations for altering the flow of air currents intercepted by the vanes and for directing light energy onto the light sensitive cells.

Abstract: A fixed pitch propeller has blades that are not solely dependent on the blade angle dictated by the helical path of the blade tip. An outboard portion of the blade has a range of blade angles that are relatively flat to operate most efficiently at lower aircraft speeds.

Abstract: A low cost assembly and method for assembly of a fan having a hub, a spider with arms and blades attached to the arms is provided. The spider is arc welded to the hub and the blades are projection welded to the arms. The blades have a root, a tip, and an ear. The width or chord of the blade decreases from the root to the ear and then increases from the ear to the tip. The blade has an air foil shape defined by the arcs of two circles. The radii of the circles and, thus the profile of the blade, change as a function of the cord length and the camber of the blade. The blades have a pitch angle which decreases from the root to the ear. The spider arms are formed to match the pitch and are rotated slightly with respect to the horizontal. The result is a highly efficient, low cost fan blade assembly construction.

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: In an axial fan, the angle of curvature of the median line of each blade in axial projection is nil at the hub and for about one third of the radial extension of the blade from the hub. The blade angle of each blade is substantially constant along the blade and the chord between the leading edge and the trailing edge of each blade is substantially constant along the blade between the hub and the outer ring.

Abstract: The invention relates to a radial-flow wheel for a turbo-engine comprising a hub and blades distributed on the hub-side outer circumference, the meridian section contour of the outer surface of the hub being a catenarian curve. This radial-flow wheel has the advantage of low frictional losses.

Abstract: An axial flow fan operates with increased efficiency, reduced noise, and improved resistance to stall. These benefits are achieved by providing a fan shroud with a bellmouth and a hub with a curved bellmouth wherein both have a substantially parabolic shape, and by providing a blade shape with an air pressure distribution that promotes smooth airflow and resists stall. The blade is provided with a twist that varies with distance from the blade root such that the work done on the air moved by the blade, whether at the blade root or tip, is substantially equal.

Abstract: The invention relates to an axial fan with an essentially cylindrical outer housing and with a fan wheel which rotates therein and the hub of which is located on the rotor of an electric drive motor, the stator of the drive motor being held by webs extending on the delivery side relative to the outer housing. The vanes of the axial fan are radially twisted and possess a forward curvature with a camber varying from the hub cross-section to the outer cross-section. In order to achieve a pressure increase, at the same time with a reduction of the operating noise, the vanes have in the hub region a cross-section designed for a low flow per unit volume and small pressure increase, but in the outer region a cross-section designed for higher values of flow per unit volume and pressure increase.

Abstract: A rotor blade includes a root, tip, leading edge, trailing edge, forward surface, and aft surface, and a pitch section disposed equidistantly between the root and tip. The blade has a forward sweep from at least the pitch section to the blade tip relative to incoming streamsurfaces of a fluid flowable over the blade.

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: A hydrodynamic retarder has a stationary element and a rotary element, each of which has a semi-toroidal cavity with a plurality of blade members disposed therein. The semi-toroidal cavities are presented in facing relation with the blade curvatures being oppositely directed. The blade members each have a fluid flow profile that accommodates constant acceleration of the fluid from entrance to exit.

Abstract: A quiet tail rotor (QTR) blade for helicopters that provides reduced noise levels and increased thrust efficiency. The QTR blade includes a first segment for connecting the QTR blade to a helicopter tail rotor hub and an outboard segment, integral with the first segment, having a configuration that reduces high speed impulsive noise and blade vortex interaction noise and provides increased thrust efficiency. The outboard segment includes an inboard segment integral with the first segment and a swept, tapered tip segment integral with the inboard segment. The inboard segment has a constant chord and a predetermined constant airfoil section profile defined by constant upper and lower surface contours. The predetermined constant airfoil section profile has a t/c ratio greater than about twelve percent of the chord at any station. The swept, tapered tip segment has a variable chord and a predetermined airfoil section profile defined by constant upper and lower surface contours.

Abstract: The known rotor blade for use with axial-flow machines is improved. The improvement resides in a novel configuration of the blade body of the rotor blade. A leading edge of a tip end portion of the blade body is inclined forward (in the upstream direction of flow) and also advances in a direction of rotation, towards a tip end surface of the blade body. In the tip end portion between the tip end surface and a cross section displaced from the tip end surface towards the central portion of the blade body by 1/2 of a chord length of the tip end surface, the configuration of the leading edge of the tip end portion is such that an angle S of skew thereof over which the leading edge of the tip end portion advances in the direction of rotation and an effective skew amount .THETA..sub.s eff thereof of the angle over which the leading edge of the tip end portion is inclined forward in the upstream direction falls in a particular region in a graph of S vs. .THETA..sub.

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 blade is overtwisted in the extremity zone from at least 0.85R so that the resulting twist is at least equal to a limiting twist .theta.limC according to the plane form Co/C(r) of the blade in this zone and so that the lift coefficient Cz has, in a first fraction of the extremity zone extending at least between r=0/85R and r=0.9R, a decreasing value remaining lower than a first limiting value CZlim1=Czm-a(r/R-b), Czm being the mean lift coefficient of the rotor and a and b being experimental constants, and in a second extremity fraction extending between r=0.9R and at least r=0.95R, the lift coefficient continues to decrease by remaining less than or equal to a second limiting value Czlim2 linearly decreasing from the value Czlim1 for r=0.9R as far as the zero value for r=R.

Abstract: A propulsor blade for an aircraft engine includes an airfoil section formed in the shape of a scimitar. A metallic blade spar is interposed between opposed surfaces of the blade and is bonded to the surfaces to establish structural integrity of the blade. The metallic blade spar includes a root end allowing attachment of the blade to the engine.