Abstract: A turbomachinery stage comprising two axially spaced blade rows, one of which is rotatable, wherein the blades of the upstream row are contoured to present a leaned wake to the downstream row. In the preferred embodiment, the blades of the upstream row extend radially from a central hub and, at a radius above the hub, are physically curved circumferentially from a radial line through the hub. The physical lean locally complements the inherent aerodynamic lean at each radius such that the integrated acoustic power of the stage is essentially at a minimum, thus maximizing the acoustic attenuation. Preferably, the constraint is imposed that the blade physical curvature is essentially smooth, continuous and without an inflection point.

Abstract: The rotor and stator wheels of a hydrodynamic retarder, with confronting annular gorges together defining a toroidal channel of circular or slightly elliptical cross-section, have blades within their gorges which are of wedge-shaped cross-section and have slightly rounded edges that may or may not coincide with the radial direction. The blades have flat leading and trailing flanks, the former including an angle of about 45.degree. - 55.degree. with the plane of rotation so as to be inclined to the axial direction at an angle of about 35.degree. to 45.degree.; the vertex angle of the wedges lies between about 15.degree. and 20.degree.. Such a blade structure can be cast in a unitary mold from which it is extracted by a helicoidal twisting motion. A suitable radius of curvature for the edge rounding is in the range of about 1.5% to 4% of the channel diameter.

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: Axial flow turbomachinery having an impeller with a plurality of contoured blades mounted within a diffuser throat and about a central rotatable hub. This blade shape is defined by the ratio of the blade root and tip chords to the minimum midsection blade chord, which is between about 1.25 and about 2.25. The ratio of blade pitch at the root and tip sections as compared with the blade midsection pitch is preferably between about 1.0 and about 1.4.This configuration of a preferred diffuser is described by the following relationship: ##EQU1## Where A.sub.t is the diffuser cross-sectional area at the diffuser throat, A.sub.o is the diffuser cross-sectional area at the outlet, l is the diffuser length from the diffuser throat to the diffuser outlet, x is a distance along the diffuser measured from the diffuser throat toward the diffuser outlet, A.sub.x is the diffuser cross-sectional area x distance from the diffuser throat and n is a value between about 2 and about 4.

Abstract: A rotor blade configuration is disclosed which greatly reduces noise generated by the low pressure compressor, or fan, of a turbofan engine. The leading edge of the blade is swept forwardly from its hub up to a point of sweep reversal and then swept rearwardly to the tip of the blade. The slope of the curved leading edge line relative to the direction of airflow is gradually decreased from the hub to the tip to maintain the velocity component, of air relative to the blade leading edge, subsonic, while the relative velocity of the air to the blade is above a critical value and supersonic. This substantially eliminates noise producing, standing shock waves along the blade leading edges. Also described are methods for determining the configuration of such blades to obtain these ends with a minimum increase in blade weight and a minimum blade bending and blade attachment stresses.

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.

Abstract: A multi-blade impeller for a hydrodynamic pump, fan or the like. Each blade has a curved pressure and a curved suction surface. The pressure surface has a curvature, the angle of inclination of which gradually increases from the leading edge to a first point and then decreases to the trailing edge. The suction surface has a curvature, the angle of inclination of which gradually decreases from the leading edge to a second point and thereafter increases toward the trailing edge. The first point is determined by the intersection of a logarithmic spiral from the trailing edge of the adjoining blade with the pressure surface, while the second point is determined by the intersection of a second logarithmic spiral from the leading edge of the other adjoining blade with the suction surface.

Abstract: An object disposed in a fluid flow and defined by two surfaces, each extending along a stream line and one of said two surfaces having a reference contour. To eliminate the danger that a violent oscillation is generated due to resonance between the natural oscillation of the object and the oscillation caused by Karman's vortex which develops at the downstream end portion of the object, said downstream end portion of the object is so formed as to provide a configuration satisfying the following relations:R1/TV.ltoreq.0.2 and R2/TV=6-10where, R1 is a radius of curvature of the first portion of object's downstream end portion which is continuous with said reference surface, R2 is a radius of curvature of the second portion of object's downstream end portion extending between said first portion and the other surface, and TV is the minimum thickness of the object between said two surfaces measured from the joining point or juncture between said second portion and the other surface.