Abstract: A flow directing element (such as a rotor blade 34 or a stator vane 44) for the turbine section 16 of a rotary machine is disclosed. Various construction details are developed which increase the aerodynamic efficiency of the flow directing element. In one embodiment, the flow directing element is a rotor blade 34 having a roughened surface which approximates the critical roughness characteristic of the airfoil. In one particular embodiment, the roughness average of the surface lies between 120 to 200 AA microinches.

Abstract: A turbine stage comprising a set of fixed vanes (1) fixed to the stator (3) of the turbine and supporting a diaphragm, followed by a set of moving vanes (8) mounted on a disk (9) which is fixed to the rotor (6) of the turbine, the periphery of the set of moving vanes (8) having seals (10) constituted by a plurality of chambers (11). The disk (9) includes suction orifices (16) opening out into the space between the diaphragm (4) and the disk (9) and disposed in the vicinty of the peripheral portion of the disk (9). The suction orifices (15) are connected by ducts (17) passing through at least some of the moving vanes (8) to outlet orifices (18) which open out in the tips of the vanes (8) downstream from the seals (10) within a chamber (11) thereof. The disturbed flow at the roots of the fixed vanes (2) and the leakage flow between the diaphragm (4) and the rotor (6) are sucked into the orifices (16), thereby improving efficiency.

Abstract: In a stator assembly for a turbomolecular pump, each stator is assembled from two semicircular portions mutually aligned and secured in place by tongue and grooves means, each such stator including a plurality of radially directed blades connecting an inner circular edge and outer circular edge of the stator, such edges occupying respective parallel displaced planes. The outer edge of each stator includes regularly outward projected tabs which bear between spacer rings to maintain axial alignment.

Abstract: A vertical shaft pump to be disposed in a pump pit comprises a pump casing having a suction opening, and an impeller disposed in the pump casing below a position corresponding to the lowest water level in the pump pit below which the pump starts to suck air through the suction opening during operation. A series of intake ports are provided in the pump casing below the impeller with equal intervals in the circumferential direction of the pump casing. These intake ports act to introduce atmospheric air into the pump casing through intake pipes when the pressure at the intake ports is lowered below the atmospheric pressure.

Abstract: The casing 24 of an axial flow compressor 12 is provided with a plurality of axially extending circumferentially spaced slots 30 in its internal cylindrical surface 32 adjacent the tips of at least one row of blades 26. A benefit in both surge margin improvement and a reduction in efficiency deficit may be achieved by positioning the leading edge of the slot 30 such that it leads the leading edge of the blade 26 by an amount termed the overhang or by reducing the closed to open ratio of the slots 30. A further reduction in efficiency deficit may be achieved by combining the overhang which individually gave the best surge margin improvement with a slot 30 closed to open ratio somewhat higher than the value which individually gave the best surge margin improvement.

Abstract: An impulse turbine stage comprising a set (1) of fixed vanes (2) fixed to the stator (3) of the turbine and supporting a diaphragm (4), followed by a set (7) of moving vanes (8) mounted on a disc (9) fixed to the rotor (6) of the turbine, the stage being characterized in that said disk (9) is provided with through ducts (12) parallel to the axis of the rotor (6) and in that the inlets to the ducts (12) opening out into the gap between the diaphragm (6) and the disk (9) are provided with scoops (15) open sideways in the direction of rotation to direct fluid into the ducts (12). The invention serves to reduce the secondary losses of an impulse turbine.

Abstract: A steam turbine including a plurality of rows of rotating blades interspersed with a plurality of rows of stationary blades incorporates a water barrier extending substantially across a suction side of each blade of at least one of the rows of stationary blades. Each of the water barriers is positioned relatively near a radially outer end of a respective blade and approximately parallel to an end wall of the steam turbine. Moisture which accumulates on the radially outer end of the stationary blades is trapped between the end of the blade and the water barrier. Any water which attempts to flow over the top of the barrier is picked up by the steam flow and broken into small droplets while being rapidly accelerated. Water held behind the barrier and which flows off the trailing edge of the stationary blade only impacts a limited extent of the following rotating blade row.

Abstract: An airfoil for a compression section 12 of a rotary machine 10 is disclosed. Various construction details are developed to increase the efficiency of the compression section 12. In one detailed embodiment, the airfoil has a spanwise axis 52 or stacking line which extends in a generally radial direction. The stacking line or spanwise axis 52 is straight over the mid-section of the airfoil and is angled circumferentially toward the radial direction in the end wall regions 58, 66 of the airfoil.

Abstract: A centrifugal fluid handling apparatus such as, for example, a centrifugal fuel pump for, for example, an aircraft engine, which includes a impeller rotatably mounted in a housing, with an annular diffuser ring being disposed about a periphery of the impeller. The annular diffuser ring includes at least one passage for discharging a fluid from the impeller, and a passive control is provided in a diffuser throat of the at least one passage at an entrance area thereof for providing a stabilized fluid discharge pressure through the at least one passage throughout an entire flow range of the fuel pump.

Abstract: Power output of a steam turbine is increased by removal of at least one stage of blading in order to increase mass flow through the turbine. A flow guide or annular ring is installed in the space in the inner cylinder or blade ring surrounding the area from which the blading stage has been removed. The flow guide has a radially inner surface conforming generally to the surface configuration of the inner cylinder surrounding the turbine blades. The flow guide presents a relatively smooth, continuous surface to inlet steam flow so that flow separation and turbulence are reduced with a corresponding increase in efficiency.

Abstract: A gas friction pump has an inlet arranged to be coupled to a vessel to be evacuated; an outlet and an outlet-side pumping stage formed of a helical gas pumping channel. The pump further has a scavenging gas inlet circumferentially surrounding the helical gas pumping channel for exposing the channel to a scavenging gas.

Abstract: The rotor has a body with recesses formed therein in which airfoil-type blades are secured. The blades have platforms which abut one another to define an annular wall which circumscribes the rotor body. One edge of each of the platforms, which abuts an adjacent platform, has a rectilinear cut-out formed therein. The resulting void constitutes a slot which extracts fluid therethrough, and each void has an evacuating duct in communication therewith for venting the extracted fluid. The voids and ducts bleed off a minimal volume of the fluid handled by the rotor, principally the volume which comprises the secondary flows. These are the secondary flows which, otherwise, would result in the formation of eddies and vortices which are susceptible of eroding the roots of the blades.

Abstract: A centrifugal fluid machine such as a pump or compressor has a diffuser with fixed vane geometry which provides significantly increased range, as compared to conventional fixed geometry diffusers, by developing what appear to be flow accelerating stall bubbles in the diffuser throat that forestall the onset of surge in the portion of the operating range near and approaching the surge point. The stall bubbles are created by fixing the suction sides of the vanes, relative to the flow impinging upon their leading edges at angles slightly more radial than is conventional, thereby creating higher than normal angles of incidence with the flow delivered by the impeller.

Abstract: In a radial compressor the device for extending the performance at small throughputs by stabilizing the impeller flow in the inlet region comprises a recess (5) in the form of a groove which is oriented in the circumferential direction of the inlet duct (6) of the compressor, whereas in the flow direction it extends with a given axial width to the impeller (2). A stabilization ring (3) is integrated into said recess (5), being arranged in front of the impeller (2) and outside the principal flow (7) of the transported medium. A plurality of blades (4,4a), which are placed on the outer circumference of the stabilization ring (3), are in turn anchored to the inner contour of the recess (5).

Abstract: A system for affecting the flow of a fluid medium relative to an object including a first plurality of surface deviations disposed on the surface of the object in contact with the fluid medium. The deviations are arranged into at least one predetermined pattern which includes a plurality of radially extending deviation sets. A second plurality of surface deviations are disposed on at least one of the first plurality of surface deviations. The second plurality of surface deviations are arranged in a second predetermined pattern which includes a plurality of radially extending deviation sets. The deviations may be indentations or projections from the surface.

Abstract: A method for optimizing thermodynamic performance of a steam turbine by matching a last stage blade flow area to condenser pressure by adjusting blade angular orientation to set gaging to an optimum value. The method is also used to correct incidence by setting blade angular orientation upstream of the last blade row.

Abstract: A method and system for maintaining forward flow direction and controlling the path of steam flow following trips of reheat turbines, by maintaining pressure differentials to control the direction and path of the steam flow. After a turbine trip, pressure at the exhaust stage is reduced by extracting steam at a point just upstream of the exhaust and dumping it to a lower pressure zone, feedwater heater, or condenser. Additionally, pressure is increased at the inlet by introducing HP exhaust into the impulse chamber. Secondly, pressure is reduced on the concave, pressure side of turbine blading nearest the turbine exhaust by applying suction to steam collection channels running the length of the pressure surfaces thereof, thereby keeping the path of steam flow in contact with the pressure surfaces of the blades.

Abstract: The disclosure illustrates a range improvement feature for a compressor wheel in which a chamber adjacent the inlet is separated from the outer periphery of the impeller wheel vanes by a wall through which communication is established between the chamber and the impeller wheel. Communication is provided by either an annular slot or a series of radial holes. The feature may be used on single stage or multistage compressors. The area of the communication is such that at high rpm, and/or high flow, flow is from the chamber inward and at lower flows the flow is from the impeller wheel outward. This bidirectional flow improves the range over twhich the compressor may operate without encountering surge.

Abstract: A compressor stage or a turbocharger having a compressor stage having an inducer shroud with two or more vents. A first vent is provided with a second vent upstream thereof, allowing for outflow during surge conditions and inflow during choking conditions. Surge line characteristics may be varied by selectively locating the position of the first and of the second vents, and by selectively determining the effective width of the vents. The vents may be circumferential slots, and may be slanted. An outer shroud is provided forming a venting chamber for recirculation of gas into the gas intake. A third vent may be provided to vent the diffuser.

Abstract: An axial fan is disclosed that includes a hub supported for rotation around the longitudinal axis of the fan, a plurality of impeller blades attached to the hub and extending radially from the axis of rotation, a shroud assembly including a band encircling the blades and spaced from the tips of the blades a sufficient distance to provide ample clearance to avoid contact between the blades and the band during shipment and operation of the fan, the shroud further including an orifice positioned upstream of the blades for preventing air from flowing between the orifice and the band, the orifice having a downstream end located adjacent to but spaced from the impeller blades and having a diameter such that the impeller blades extend outwardly from the hub beyond the orifice so that the flow of air over the tips of the impeller blades is substantially reduced, which increases the efficiency of the fan.

Abstract: A generally tubular-shaped or cylindrical vehicle for operation in a fluid medium is formed with a bluff or stubby afterbody and utilizes an actuator disc type propeller of approximately one-half to three-fourths of the diameter of its housing at its rear for propulsion. The propeller, in addition to driving the vehicles, is spaced from the body such that it inducts half or more of the boundary layer flow, thereby acting to draw the flow smoothly over the after part of the vehicle with a minimum of flow separation and turbulence and drag caused thereby. Steering in pitch and yaw is provided by a plurality of fins located just forward of the bluff rear surface of the vehicle. In this location the fins are more than usually effective, hence smaller than customary, because they are exposed to a fluid velocity which is near or above free stream velocity rather than at a lower velocity which is usual in vehicles having tapered afterbodies.

Abstract: A method and apparatus for work expanding a cryogenic liquid wherein the liquid is expanded in a manner to avoid a transient pressure drop below the flash point thus reducing the potential for cavitation and consequent operating inefficiencies.

Abstract: An improved diffuser is provided for centrifugal compressors and the like. The diffuser has a movable wall to which is attached a plurality of ribbed vanes.

Abstract: A rotary pump with an inlet flow duct having a convergent section upstream the tips of the rotor blades. The convergent section decreases the cross-sectional flow area of the inlet flow duct prior to the flow being introduced into the rotor, thereby creating a substantially uniform velocity profile in the flow just upstream the rotor blades.

Abstract: A flow fence for a turbo fan jet engine, as taught by Stein et al. in U.S. Pat. No. 3,841,790, is modified by the provision of serrations about its internal circumference. Thus, when the modified flow fence is inserted into or removed from the flow field, a more gradual transition occurs in the flow thereby improving surge margins.

Abstract: A system for affecting the flow of a fluid medium relative to an object including a plurality of surface deviations disposed on the surface of the object. The deviations are grouped into at least one set and the sets are arranged into at least one predetermined pattern. The deviations cover only a portion of the object's surface.

Abstract: An axial-flow fan having a stepped housing defined by an inlet part and an outlet part, the outlet part having the inside diameter smaller than the inside diameter of the inlet part, the inlet part adjoined to an inlet tube of an inside diameter substantially equal to the inside diameter of the outlet part of the housing. The outlet part of the housing accommodates a rotor having blades arranged such that their forward tips are located in the inlet part of the housing and a ferrule being secured at a certain distance from the inlet tube coaxially with the housing to form with the housing an annular chamber having on the side of the rotor an inlet passage and on the side of the inlet tube an outlet passage. Rigidly affixed in this chamber are guide vanes pointing by their heels to the inlet tube. The heels of the guide vanes extend to the inlet tube and are radially curved at a portion between the inlet tube and the ferrule to form an annular radial grill.

Abstract: A method and apparatus for eliminating vortex whistle noise in a radial-to-axial compressor intake uses a plurality of flow fences (36) disposed along the radially inner gas passage boundary (10). The fences (36) disrupt a portion of the swirling gas flow (32) resulting from the position of a plurality of pivotal inlet guide vanes (28) disposed about the radially outward facing inlet (18).

Abstract: A gas turbine engine having a turbine casing with a contoured entry. The contoured entry is located upon the housing such that upon assembly of the engine the contoured entry is located relatively directly prior to the turbine blades. The contoured entry is positioned relatively directly prior to a spacing between the tips of the turbine blades and the housing such that gases are directionally restricted away from the spacing and into the turbine blades.

Abstract: The present invention provides a vortex-free shrouded inducer assembly comprising a forwardly extended shroud (24) and surfaces (36,38) defining a recess proximate to the forward lip (42) of the shroud for favorably diffusing and mixing the flow (54) tending to recirculate about the outer periphery (30) of the inducer prior to its being discharged through nozzle (40).

Abstract: A turbine stage which has a stationary blade set (204) followed by a moving blade set (205) which have blades (206, 207) mounted between a floor plate (201, 211) and a ceiling plate (202, 212). The surfaces of the ceiling plate (202, 212) and/or of the floor plate (201, 211) have as their meridian lines sinusoids with the maximum for the ceiling plate (202, 212) and the maximum or the minimum for the floor plate (201, 211) located in the plane between the blade sets. The curvature of the sinusoid at the outlet end of the stationary blade set (204) is calculated so as to make the tangential static pressure gradient equal to the radial static pressure gradient at the ceiling plate and/or at the floor plate equal at the outlet end of the stationary blade set (204). The disturbances are confined to restricted zones and the efficiency of the stage is thereby improved.

Abstract: A turbo-molecular pump has stator discs 2 separated from one another by spacer rings 3 constructed in such a manner that gases streaming back can re-enter the suction space 8 through reduced portions 5 at the outer diameter and through radial recesses 6. Inner reduced portions 7 serve for the additional location of the stator discs 2.

Abstract: A turbomachinary airfoil in one form comprises a pressure side and a suction side curved circumferentially outward in the direction that the suction side faces. The invention is effective for reducing both radial and circumferential boundary layer pressure gradients thereby reducing airfoil aerodynamic losses. In another form of the invention the airfoil is a vane of a turbine vane assembly having an inner and outer shroud wherein the vane in addition to being curved is leaned circumferentially outward in the direction that the suction side faces.