Abstract: A tapered twisted rotating blade for the fourth rotating blade row of a BB71 and BB471 turbine has a shroud segment integrally formed on the tip of the airfoil portion such that the shroud is dimensionalized according to materials used so that the tuned frequencies remain the same regardless of materials used, based on changes in Young's modulus due to use of different materials. The blade also has a pitch to chord ratio that increases linearly with length of the blade.

Abstract: A process for manufacturing impellers of turbine pumps provides for subjecting disks corresponding to the impeller to be obtained to electrical discharge machining, using tools in form of plates provided with radial slits extending along at least an arc of circumference and opening into hollow areas. A combined motion of rotation and translation is imparted to the disks, thus generating twisted blades having a profile with defined geometric characteristics. A one-piece rotor can be manufactured employing open tools with slits formed along a semicircumference, and two passages in succession of the workpiece through the tools, moving the workpiece with a combined motion of rotation and translation. An advantageous application of the articles manufactured by this process is for rotors of turbomolecular pumps, since the compression ratio and the pumping speed are optimized and a considerable structural sturdiness of the article is obtained.

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 regenerative toric pump in which undesirable noise generation and leakage through the clearance gaps between the impeller and housing is minimized includes an impeller having vanes lying in general planes radiating from the impeller axis disposed at variable spacings from each other in a geometrically balanced pattern. Recesses in one of opposed side surfaces on the impeller and housing are arranged in a pattern such as to minimize leakage through the clearance gap between those surfaces from points in the pump chamber which are at different pressures.

Abstract: A freestanding mixed tuned taper-twisted steam turbine blade having an X-X axis parallel to a rotor axis, includes a root portion having a root center line defined by a root center line radius, a platform portion connected to the root portion; and an airfoil portion connected to the platform portion and having a leading edge, a trailing edge, a convex section-side surface, a concave pressure-side surface and a profiled tip, the platform portion having a concave edge, a convex edge, a first end in vertical proximity to the leading edge of the airfoil portion and a second end in vertical proximity to the trailing edge of the airfoil portion, the concave edge being sloped towards the root center line radius at a predetermined angle of slope to define an arcuate sloped surface, and having a sloped flat cut-out surface formed at the second end of the platform portion, the flat cut-out surface having the same predetermined angle of slope as the concave edge and sloping towards the X-X axis.

Abstract: A turbine blade includes an airfoil portion, a platform portion from which the airfoil portion extends upwardly, and a root portion extending downwardly from the platform portion, the root portion includes in descending order an upper-most root neck, an intermediate root neck, and a lower-most root neck, an upper-most lug being formed beneath the upper-most root neck, an intermediate lug being formed beneath the intermediate neck, and a lower-most lug being formed beneath the lower-most root neck. The upper-most neck includes a first top radius R1 and a second lower radius R2, wherein a length of R1 is about 30% greater than a length of R2.

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: The fan blades of a hot gas blower are cooled by the forced passage of cooling air or gas through the blades, the cooling air or gas being vented either into the hot gases or being isolated therefrom and being recirculated after cooling.

Abstract: Crack formation in the root portion of a turbine blade is prevented by locating the trailing edge of the air foil portion at the base section thereof in close vertical proximity to the uppermost root neck, thus minimizing trailing edge overhang which has been determined to be the cause of root tracking.

Abstract: A liquid ring vacuum pump includes a vacuum pump housing composed by two opposed end walls spaced by an annular wall defining a vacuum pump chamber; a shaft extends into the vacuum pump chamber; a rotor is mounted on the shaft and is arranged eccentrically in the chamber; the rotor includes a rotor central portion and a plurality of vacuum pump vanes extending therefrom toward the annular wall; the rotor central portion and the vanes having at least one lateral edge adjacent the end walls facing the annular wall, the lateral edges and the end walls form a clearance therebetween; and the clearance between the edges and at least one of the adjacent end walls of the vacuum pump chamber increases towards the annular wall. A combination of the liquid ring vacuum pump with a centrifugal pump for pumping multi-phase liquids such as gas and solids containing fiber suspensions of the pulp and paper industry is also provided.

Abstract: In a mobile blade of a gas turbine engine comprising a root, a platform, and a vane forming the aerodynamic portion of the blade, the vane is arranged so that the geometric locus of the centers of gravity of successive cross-sections of the vane between the platform and the tip of the blade vane is a curve including at least one straight line portion which is offset relative to a radial straight line contained in the axial plane of symmetry of the blade root and which is joined progressively to the origin where the radial straight line intersects the junction of the vane with the platform and root of the blade. In the case of a blade with an intermediate shoulder or fin on the vane, the locus of the centers of gravity of the vane cross-sections includes a second straight line portion offset relative to the first straight line portion and connecting assembly therewith in the region of the fin.

Abstract: A blade for a steam turbine has a concave, pressure-side surface which has a constant radius of curvature, while the convex, suction-side surface has a continuously increasing radius curvature. The constantly increasing radius of curvature allows fluid to accelerate and thus ensure a small boundary layer of thickness. The center of gravity of the blade tenon is located above the center of gravity of the airfoil which will reduce the steam bending stress applied at the base of the airfoil as well as at the root of the rotor blade.

Abstract: In a turbomolecular pump, the blade angle of each of rotor blades relative to the plane of a rotor gradually decreases from its base toward its outer most periphery, and the opening ratio and relative blade interval of said rotor blades are made substantially constant from the base of the rotor blade to the outer most periphery of said rotor blade.

Abstract: A turbine blade is designed to avoid having to machine a part of the last blade assembled in a row in order to make a fit. The location of the root pivot center was carefully selected to be located in vertical proximity to a leading edge of the platform.

Abstract: This pump for refrigerating systems, in particular for aeronautical applications, comprises a pump body accommodating an impeller rotatable about a main axis; the impeller is substantially disk-shaped and has, on at least one of its faces, a plurality of radial blades arranged along a circular crown which is concentric to the main axis. The radial blades are accommodated in an annular duct which extends in the pump body concentrically to the main axis and is axially delimited, on one side, by the blade bearing face of the impeller; the annular duct has an intake port and a delivery port which are angularly spaced with respect to the main axis for the inflow and outflow of a fluid and is closed in an axial direction at least in the region not affected by the ports, so that when the impeller rotates the fluid advances along the annular duct from the intake port to the delivery port forming vortices about the circumference defined by the annular duct.

Abstract: A two-stage turbine includes a first stage comprising a first stator having blades configured for accelerating the drive fluid to supersonic velocities and directing the fluid to the impulse blades of the first rotor. The turbine's second stage includes a second stator having blades configured for directing the fluid from the first stage to the reaction blades of a second rotor at a sonic velocity. Efficient operation of the turbine over a broad range of drive fluid velocities is achieved by providing the stators and rotors with elliptical leading edges to form high angles of attack and providing extended stator tail sections to control fluid flow to the rotors.

Abstract: An improved gas turbine engine blade having increased resistance to foreign object damage is disclosed. The blade includes a swept-back leading edge portion in the tip region of the blade for improving resistance to tip curl due to foreign object impact.

Abstract: A retrofitted rotor blade having a longer length than an original rotor blade provided for a steam turbine rotor assembly has a tuned airfoil portion with natural resonant frequencies in a plurality of vibrational directions similar to the original rotor blade. Since lengthening the blade causes a decreased and resonant frequency, a unique combination of tuning techniques raises the resonant frequencies to the required levels. The tip of the retrofitted rotor blade is profiled to increase the natural resonant frequency in the second mode of vibration, which is in the axial direction of the rotor.

Abstract: Replacement low pressure end blading for a utility power steam turbine having an extended length compared to original equipment end blading providing higher efficiency. The blading incorporates extended flat areas on the blade trailing edge for improved flow characteristics and reduced losses. Mass distribution is used to tune the blade to avoid natural harmonic frequencies coincidental with turbine rotational frequencies or harmonics thereof. Blade root modifications are included to facilitate installation.

Abstract: Directly driven propeller whose propeller blades are provided with slats and which is designed for a lower blade tip Mach number in order to reduce the propeller noise. The slats are rigidly connected to the propeller blades and the slat tips lie on a diameter given by the equation ##EQU1## where LTLP=lower transonic limit of the particular blade configuration including slata.sub.o =velocity of sound in airv.sub..infin. =flight speedn=propeller rotational speed.

Abstract: A turbine blade produced from reinforced plastic material having a plurality of reinforcement sections (4, 6), arranged so that the direction of the reinforcement, and/or the structure, and/or the material in one section (4) differs from the corresponding reinforcement in another section, (5, 6), but that the reinforcement material in one section extends mainly in the same direction. The turbine blade also is so designed, that the deformations caused by loads and stresses optimize its pitch at increasing load.

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: A swept leading edge blade (10) rotates in a stream of air (26) and experiences supersonic relative air velocities over at least a portion of the blade surface. The maximum camber points (28, 40) of adjacent blade segments (20, 18) are located to prevent intensification of the compression wave generated by each segment (20, 18).

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: To minimize secondary losses and flow maldistribution, an aerofoil such as a gas turbine nozzle guide vane, is designed so that in the throat defined by the trailing edge of one aerofoil and the flank of the adjacent aerofoil, the local gas flow streamlines are normal to the trailing edge of the aerofoil at the point of intersection.

Abstract: A gas turbine engine nozzle guide vane has "barrelled" shape, producing an "hourglass" shaped passage between adjacent vanes. These shapes promote radial pressure gradients which reduce secondary flaws in the motive gas passages.

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: A device and method for reducing the flow resistance of air foils utilizes one or more flow compressors on the leading edge of the foil. The gas flowing in front of the leading edge is compressed and is expanded on the upper surface of the wing so that through induction of the expanded gas, gas from the area of the lower surface of the wing is admixed to increase the flow on the upper surface of the wing. The direction of the admixed gases is such that the velocity of the gas flowing out at the trailing edge of the wing is identical over the entire wing length. The separation point of the flow is displaced towards the trailing edge of the wind and, in the direction of the tip of the wing, the pressure of the gas flowing over the upper surface of the wing is increased.

Abstract: The invention comprises a blade for a gas turbine engine including an airfoil portion having a non-linear stacking axis which is effective for generating a compressive component of bending stress due to centrifugal force acting on the blade. The compressive component of bending stress is provided in a life-limiting section of the blade, which, for example, includes trailing and leading edges of the blade. Inasmuch as the stacking axis, which represents the locus of centers of gravity of transverse sections of an airfoil portion of the blade, is non-linear, an increased amount of a compressive component of bending stress can be generated at a life-limiting section between root and tip sections of the blade without substantially increasing bending stress at the root of the blade.

Abstract: A rotor or stator blade for an axial flow compressor has one or both of its end portions designed to minimize the interference between the annulus boundary layer and the blade. The basis of the invention is that the aerofoil is designed so that each section of the aerofoil through the boundary layer performs a constant amount of work per unit height.

Abstract: A rotor for a gas turbine exhibits three-dimensionally curved blades which are curved counter to the direction of rotation of the rotor in the radial flow region. The blades are arranged on a hub with a disc-shaped terminal region. In order to achieve a more highly aerodynamic blade shape with a simultaneous reduction of the moment of inertia of the rotor, the blades exhibit in the axial direction mean camber lines which extend centrally in the radial direction between the pressure side and the suction side of the blades, the mean camber lines being describable by a 2nd order curve equation.

Abstract: A turbine blade of a low blade profile loss with a crossing point of an inlet angle .alpha..sub.1 an outlet angle .alpha..sub.2 being located in a position in which a distance between a crossing point of the outlet end of the blade is greater than one-half of the blade width L.sub.ax, with the inlet angle .alpha..sub.1 being in the range of 35.degree.-40.degree. and the outlet angle .alpha..sub.2 being in the range of 25.degree.-28.degree.. A ratio of a narrowest width S.sub.2 of the flow channel at the blade outlet end to a narrowest width S.sub.1 of a flow channel defined between a backside of the blade in an area of the crossing point and a front side of adjacent blade lies in the range of 0.81-0.96. A ratio of a distance L.sub.ax to a blade width L.sub.ax is in the range of 0.5-0.54, with a ratio of a distance L.sub.m from an outlet end of the blade to the blade width L.sub.ax being in a range of 0.75-0.89.

Abstract: The present invention provides improvements to fan rotor blades of turbofan gas turbine engines. Increased low cycle fatigue life is sought, and a specific object is to obtain a more nearly uniform chordwise distribution of maximum stress levels across the root sections of fan blades.In one effective embodiment incorporating concepts of the present invention the root section of a fan blade is contoured to an arcuate geometry which approximates the contour of the airfoil cross section at the inner wall of the working medium flowpath. Further contour specifications for reducing local stress levels are discussed.

Abstract: A kinetic hydro energy conversion system having a turbine for mounting in a hydro energy source, wherein the turbine comprises a rotor having conformal blades and a screen for horizontally deflecting debris from the blades.

Abstract: A torque converter apparatus having a sprag-type stator is improved by grinding the fluid directing vanes to have a substantially flat surface and by replacing the one-way rotating sprag with a non-rotating solid sprag billet.

Abstract: The invention comprises a blade for a gas turbine engine including an airfoil portion having a non-linear stacking axis intersecting a reference radial axis that is effective for generating a compressive component of bending stress due to centrifugal force acting on the blade. The compressive component of bending stress is provided in a life-limiting section of the blade, which, for example, includes trailing and leading edges of the blade. Inasmuch as the stacking axis, which represents the locus of centers of gravity of transverse sections of an airfoil portion of the blade, is non-linear, an increased amount of a compressive, component of bending stress can be generated at a life-limiting section between a root and tip of the blade without substantially increasing bending stress at the root of the blade due to the non-linear stacking.

Abstract: A dual alloy turbine wheel manufacture of a cast integral blade ring pressure-sealed to a wrought alloy hub and thereafter bonded thereto by hot isostatic pressing.

Abstract: A turbine which rotates in the same directional sense for both directions of throughflow of a working medium contains rotor blades possessing an aerofoil-shaped profile which at least over a portion of the length of the rotor blades is subdivided into profile parts or portions in order to improve the flow of the working medium about the rotor blades. The profile parts of the rotor blades are non-symmetrically constructed or arranged at least in part with respect to each plane which is perpendicular to the momentary throughflow direction of the rotor. It is therefore possible to reduce the dimensions of the turbine with essentially the same power output. Such type of turbine is particularly suitable for extracting energy from the movement of waves of bodies of water, such as the sea water of the ocean, and air moved by the waves alternately in opposite directions serves as the working or flow medium.

Abstract: Axial flow impeller having at least two rows, preferably three rows, of a plurality of blades secured substantially radially to a rotor for rotation in a plane about the axis of the rotor. The blades have the same pitch throughout their lengths with the blades of the first row having a pitch angle less than the stall angle of the blades, preferably about 22.degree., the blades of the second row having a pitch angle greater than the pitch angle of the blades of the first row and less than the stall angle of the blades, preferably about 13.degree. greater than the pitch angle of the first row of blades, and the blades of a third row of blades having a pitch angle greater than the pitch angle of the blades of the second row and less than the stall angle of the blades, preferably about 13.degree. greater than the pitch angle of the second row of blades.

Abstract: The present invention relates to turbine blades and in particular to turbine blades for use in gas turbine engines. Tensile stresses are introduced into turbine blades when they rotate at high speeds on a turbine rotor. In order to minimize the stresses in an outer skin of an aerofoil of the turbine blade, the outer skin is secured to a platform and an inner core, and in operation a temperature difference is set up between the outer skin and the inner core. The temperature difference produces a thermal compressive stress in the outer skin which opposes the tensile stress produced due to the rotation of the turbine blade. The extremities of the outer skin may be secured to the platform with either a tensile or compressive prestress depending upon the temperature difference between the outer skin and inner core at normal operating conditions.

Abstract: A guide blade set for diverging jet streams in a steam turbine which has blades (2, 2') whose concave and convex surfaces are orthogonal firstly to the jet stream floor plate (3) and secondly to the jet stream passage ceiling plate (4) at their respective ends.Efficiency is improved by reducing losses in the neighbourhood of the jet stream ceiling plate.

Abstract: A bladed flow duct, for example in an axial flow turbo engine, is defined between two adjacent blades and the respective duct floor. In order to reduce secondary flow losses, the flow duct is provided with an arched zone (13, 13') projecting from the duct floor (10, 10') and extending along a portion of the suction side of the adjacent blade wall for producing a pressure rise or a reduction in the transverse pressure gradient over a relatively long forward and/or central portion of the duct as viewed in the flow direction (17) from the entrance end (21) to the exit end (22) of the duct. For this purpose the arched zone (13, 13') has a number of sections in the flow direction (17). A first section (23) starting in the entrance side of the duct is substantially or completely concave for causing said pressure rise. A second or central section (24) forms a convex peak and particularly a duct throat near the exit side of the duct. A third section (25) slopes down to the exit end (22).

Abstract: A flow directing assembly 14 having an airfoil section or shape 28 of the type adapted for use in an axial flow gas turbine engine is disclosed. The cambered meanline MCL of the airfoil shape is formed of a front circular arc FA and a rear circular arc RA. A thickness distribution TD is applied to the meanline to form the convex suction surface 20 and the concave pressure surface 22. The airfoil section exhibits good aerodynamic performance as compared with an equivalent circular arc airfoil in a transonic flow field. A method for making the airfoil shape is disclosed. The method includes the steps of: forming a cambered meanline of two circular arcs; forming a thickness distribution about the conical chord line B.sub.t ; and applying thickness distribution to the cambered meanline such that a portion of the suction surface is stretched and a portion of the pressure surface is compressed.

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: An article such as a gas turbine rotor blade or bladed rotor is made by consolidation of metal powders contained in a mould using the technique of hot isostatic pressing. Different properties are produced in different portions of the mould corresponding to those parts with either metal powders of different alloys or with metal powders made from one alloy but differently pretreated, e.g. by rolling, to impart mechanical strain into the powders.

Abstract: A turbine or like rotary machine of the kind in which a fluid, either a liquid or gas, is arranged to act on a plurality of generally radially extending rotor blades, has each rotor blade fixed in position relative to the rotor hub and is substantially symmetrical about a plane perpendicular to the rotor axis, the blades having surfaces which are of generally aerofoil shape and being mounted with their leading edges facing in the same circumferential direction. The rotor of such a turbine can be driven by a generally axial flow of fluid, the direction of rotation being unchanged when the direction of flow of the fluid is reversed, so that it can be used to advantage in an oscillating or periodically reversing fluid flow. Such a flow may be provided or produced for example, by naturally occurring movement of air or water.

Abstract: The invention finds application in the manufacture of working blades of a length exceeding that of the blades known so far, without infringing the limitations issuing from flow considerations and strength of the rotor. The blade comprises two different sheets deliminated by a suitably selected intermediary cross section of the blade. Each of the sheets is formed according to a different law dictated by strength and flow considerations. Beginning from the cross-section which delimits the sheets, the sheets are twisted in opposite directions.

Abstract: A gas turbine unit comprising an expansion turbine, a compressor and a turbine engine arranged in sequence on a common shaft. The rotor element of the expansion turbine comprises fan blades having a straight non-curved profile. Guide vanes are provided upstream of the expansion turbine to form a throttling device for controlling the flow of air to the expansion turbine. The guide vanes are adjustable relative to the blades of the expansion turbine to deflect the air to vary the throttling effect to cause the expansion turbine to operate alternately as a compressor and a turbine in response to the adjustment of the guide vanes.

Abstract: An improved rotor for a side-channel compressor in which the ratio of the pressure of the compressor at zero output and the suction pressure of the compressor is greater than or equal to 1.79 and which rotor includes a plurality of spaced-apart blades having cells interposed therebetween. The improvement of the invention comprises the blades having a thickness dimension chosen so that the ratio of the blade cell volume to the sum of the blade cell volume and the blade volume is a maximum value of 0.72 and a minimum value of 0.45/(p.sub.max /p.sub.1 -1).sup.2.

Abstract: A turbine arrangement for a gas turbine engine having a sloped gas flowpath through the turbine. The radial axes of the rotor blades and stator vanes in the sloped flowpath are tilted such that the axes are substantially normal to the mean flow streamline of the gases. This arrangement reduces tip losses and thereby increases engine efficiency.