Showing papers on "Axial compressor published in 1970"

Performance Estimation of Axial Flow Turbines

Abstract: A comprehensive method of estimating the performance of axial flow steam and gas turbines is presented, based on analysis of linear cascade tests on blading, on a number of turbine test results, and on air tests of model casings. The validity of the use of such data is briefly considered. Data are presented to allow performance estimation of actual machines over a wide range of Reynolds number, Mach number, aspect ratio and other relevant variables. The use of the method in connection with three-dimensional methods of flow estimation is considered, and data presented showing encouraging agreement between estimates and available test results. Finally ‘carpets’ are presented showing the trends in efficiencies that are attainable in turbines designed over a wide range of loading, axial velocity/blade speed ratio, Reynolds number and aspect ratio.

Intra-Stator Transport of Rotor Wakes and Its Effect on Compressor Performance

Abstract: Rotor wakes intrastator transport effects on high Mach number axial flow compressors performance, considering stagnation temperature profile and rotor blade loss factor

Fan engine with counter rotating geared core booster

Abstract: The disclosure describes a turbofan engine having high and low pressure compressors wherein the low pressure compressor, or booster, comprises two counter rotating elements, a rotating duct which carries fan blades on its exterior surface and compressor blades on its interior surface and a conventional compressor rotor which rotates in a direction counter to the direction of rotation of the rotating duct. Alternative gearing schemes for coupling the rotation of the fan to the rotation of the low pressure compressor are shown.

Gas turbine engines with compressor rotor cooling

Abstract: The disclosure shows a system for cooling the rotor of an axial flow compressor incorporated in a gas turbine engine. Air is ducted from the first compressor stage discharge into the interior of the rotor. This cooling air flows to the downstream end of the rotor and is then ducted back into the compressor inlet.

Guide blades of axial compressors

Abstract: A guide blade arrangement of axial compressors in which the guide blades are provided with openings for sucking off the boundary layer, which are in communication by way of hollow spaces provided in the blades with a space of relatively low pressure

Jet engine air compressor

Abstract: A gas turbine jet engine is modified to act as an air compressor by removing the propulsion nozzle to increase the expansion ratio across the driving turbine and by injecting steam generated in the jet exhaust into the driving turbine to restore volume flow lost by removal of compressed air from the compressor.

Control system for rotary compressors

Abstract: A Control system for a motor-driven, rotary air compressor which includes a suction control throttling valve at the compressor inlet. The control system automatically shuts down the driving motor whenever the compressor operates near its unloaded condition for an extended period of time. The control system also restarts the driving motor upon a subsequent demand for compressed air.

Split compressor gas turbine

Abstract: A GAS TURBINE ENGINE HAS A DOBULE-ENTRY CENTRIFUGAL COMPRESSOR, COMBUSTION APPARATUS SUPPLIED BY THE COMPRESSOR, AND A TURBINE HAVING VARIABLE NOZZLE AREA SUPPLIED FROM THE COMBUSTION APPARATUS AND DRIVING THE COMPRESSOR. THE TURBINE MAY DRIVE THE LOAD OR A SECOND POWER TURBINE IN SERIES WITH THE COMPRESSOR DRIVING TURBINE MAY BE PROVIDED. A REGENATOR TO EXCHANGE HEAT BETWEEN TURBINE EXHAUST AND COMPRESSED AIR IS PREFERABLY PROVIDED. ONE SIDE OF THE DOUBLE-ENTRY COMPRESSOR IS PROVIDED WITH A SHUT OFF VALVE WHICH CLOSES THE ENTRANCE TO THIS SIDE FOR OPERATION AT IDLING AND UNDER LIGHT LOADS. THE VALVE IS OPENED COMPLETELY FOR HIGHER POWER OUTPUT OF THE ENGINE.

Three-dimensional vortex theory for axial compressor blade rows at subsonic and transonic speeds

Abstract: The three-dimensional, inviscid, small-perturbation, compressible flow past a lifting axial compressor rotor is analyzed. Because of its three-dimensional nature the solution applies for transonic as well as subsonic relative speeds. A potential solution is constructed, representing B lifting blades each with bound vorticity of total strength F(r). If F(r) is nonuniform, vorticity is shed downstream, which in turn induces a modified flowfield at the rotor. In addition, for supersonic relative tip Mach numbers, acoustic radiation occurs. Both of these effects introduce drag at the blades. Given F(r), or the mean change in circumferential velocity, the first-order static and total pressure rise, axial velocity change, etc., are determined. A second-order calculation yields the power required, including the effects of induced and wave-drag. An ideal efficiency is defined which indicates the penalty associated with departure from constant work design, as well as with losses due to acoustic radiation. For a 20% variation of F across the blade span, the combination of both types of losses for a typical, but lightly-loaded, transonic rotor are of the order of 0.5%.

Centrifugal Compressor Machines

Abstract: : The book discusses fundamentals of theory, calculation and design of centrifugal compressor machines. There are examined processes of flow and losses in elements of the stage and the effect of separate structural factors of the flow area on efficiency. There is substantiated the rational selection of elements of the flow area: rotor wheel, diffuser, return stator and volute. There are provided calculations of compressor machines with cooling, calculations of disks for strength and of shaft for critical number of revolutions. There are examined systems of automatic control of compressor machines, and also questions of their testing. (Author)

Pressure equalizer for unloading a compressor during start-up

Abstract: A pressure equalization passage, controlled by a normally open valve, intercouples the discharge outlet and suction inlet of a motor-driven compressor anytime the compressor is inoperative With an equalized pressure across and therefore no load on the compressor, the starting torque requirement for the motor will be minimized Upon and responsive to compressor operation, the valve closes and interrupts the passage to segregate the discharge outlet and suction inlet from each other This is achieved by a spring-biased axially movable nozzle in the discharge line from the compressor, which nozzle serves as a movable valve member When the compressor operates, fluid flow in the nozzle creates a pressure differential resulting in a force which moves the nozzle in opposition to its spring bias and to an operating position effective to close a vent in the equalization passage In response to termination of fluid flow, occurring when the compressor ceases operation, the nozzle returns to a home position under the influence of its spring bias and unblocks the vent In one application of the invention where the compressor pumps fluid in a closed series flow path, the nozzle also functions as the nozzle section of a jet pump which entrains or syphons fluid, previously diverted from the flow path and used for compressor motor cooling, back into the discharge line

Method and device for providing a control of the velocity profile of the working medium in the inlet of flow medium

Abstract: A method and apparatus for controlling the velocity profile of the working medium of fluid actuated or fluid impelling mechanisms, such as water and gas turbines, turbopumps, compressors, etc., having radial or axial flow patterns in which a control fluid of the same character as the working fluid is introduced tangentially into the working fluid at the working fluid inlet to impart a rotational motion to the working fluid either in the same direction as the direction of rotation of the rotor of the mechanism or in a direction opposite to the direction of rotation of the rotor, and at a substantial distance forward of the rotor, with respect to the direction of flow of working fluid, and the rotational movement is then amplified by restricting the flow path of the working fluid prior to its contact with the rotor. Preferably, the control fluid is introduced through a plurality of orifices or nozzles distributed along radially disposed conduits in the working fluid inlet and the control fluid is obtained from the outlet of the machine or from both the outlet and an external source and is passed through a control apparatus, such as a fluid amplifier system, to control the volume, pressure and distribution through the orifices or nozzles.

Steam or gas damper with axial and radial baffle plates

Abstract: A damper for steam or gas comprising an inlet, a first axial flow section, a second radial flow section and an outlet flow section. The axial flow section is formed of a conduit having a plurality of successively larger diameter perforated plates. The radial section is formed of a plurality of perforated coaxial cylinders. The housing surrounds the first and second sections and provides an annular tortuous passage to atmosphere.

Method of changing capacity of fluid reaction device

Abstract: The capacity of a centrifugal compressor having an overhung rotor with a plurality of separate stage impellers is changed by machining the free curved edge of each impeller blade by an equal amount for each impeller along the entire curved edge length from the radially extending axial flow edge to the axially extending radial flow edge. Additional separate shrouds are provided that differ in diameter from the shrouds supplied with the impellers before machining by an amount equal to the diametric change occurring during machining. Further, separate annular diffusers are provided, with each diffuser having integral blades with free terminal edges lying in a common plane perpendicular to the axis of rotation and engaging the adjacent shroud, so that these radially extending diffuser blade edges may be machined by an amount equal to the axial component of machining on the corresponding impeller blades.

Oil metering system for rotary compressor

Abstract: An oil metering system for a rotary compressor of the sliding vane type in which a valve assembly continuously meters oil flow into the compressor during its operation and is effective to prohibit oil flow into the compressor during its ''''off'''' cycle, thereby preventing reverse rotation of the compressor rotor previously caused by balancing or equalizing of the inlet and outlet pressures internally of the compressor.

Small centrifugal heat pump

Abstract: A variable capacity mechanical refrigeration system for heat pump or cooling operation, with a variable speed centrifugal compressor motor drive that uses an electronic frequency conversion apparatus which is sensitive to and controlled by, discharge or suction pressure and which includes means of preventing overloading during start up of the compressors.

Fluid Mechanics Analysis of High-Pressure-Ratio Centrifugal Compressor Data

Abstract: : The results of a review and distillation of the fluid dynamic information gained during a program to develop superior high-pressure-ratio compressors for small gas turbine service are reported. The objectives were to critically test the design flow models proposed by Welliver and Acurio (1967), to improve these models where feasible, and then to redesign the compressor with concrete guidelines for reaching the U. S. Army Aviation Materiel Laboratories (USAAVLABS) target of pressure ratio 10 and 80% total to static stage efficiency at 2 lbm/sec flow.

Supersonic compressors with conical flow

Abstract: In an axial supersonic compressor with conical flow, compressing of two flows occurs together, only in that portion of their course in the mobile wheel where they are compatible in terms of pressure The compressor thus makes it possible to subject two flows, which are compatible in terms of pressure, to two different compression ratios in one and the same compression stage, either upstream or downstream from this stage

Heat Transfer At The Outer Surface Of ARotating Cylinder In The Presence Of AxialFlows

Abstract: A numerical analysis has been made of forced convection heat transfer for axial flow of air along the outer surface of a rotating cylinder. The analysis was two dimensional with an allowance for a swirling component of velocity around the cylinder. The results show that an exponential law correlates the numerical data well with an exponent of 0.8, such as is obtained for turbulent flow past a flat plate. The results were compared with that available for cross flow of air but it is shown that for axial flow, rotation never becomes dominant enough to make the Nusselt number independent of the blowing Reynolds number.

Calculation of a laminar axial flow of a nonlinear viscoplastic medium in an annular channel

Abstract: We calculate the fundamental field and integral characteristics (velocity profiles, tangential stresses, outflow rate, pressure loss, boundaries of the quasirigid core) for a nonlinear viscoplastic Cesson medium in stationary stabilized flow in a coaxially cylindrical channel.

After-guide-blading of an axial compressor

Abstract: An after-guide blading of an axial compressor, particularly of a supersonic axial compressor, in which a profile ring is provided between the walls defining the after-guide blading which partially projects into the guide blades; the cross-sectional configuration of the profile ring in a plane parallel to and passing through the compressor axis is such that it increases in a first section and decreases again in a second section.

Cold-air investigation of a turbine with transpiration-cooled stator blades. 2 - Stage performance with discrete hole stator blades

Abstract: Cold air tests on axial flow turbine with transpiration cooled discrete hole stator blades to determine coolant flow ejection effect on turbine aerodynamic performance

Analysis of in-flight pressure fluctuations leading to engine compressor surge in an F-111A airplane for Mach numbers to 2.17

Abstract: F-111A airplane in-flight inlet pressure fluctuations for engine compressor surge, discussing average turbulence factor

Experimental Performance in Annular Cascade of Variable Trailing-Edge Flap, Axial-Flow Compressor Inlet Guide Vanes

Abstract: Aerodynamic performance of a variable-geometry axial-flow compressor inlet guide vane configuration for a gas turbine unit was determined in a series of annular cascade tests. The variable-geometry vanes used uncambered, symmetrical airfoil sections as the basic blade profile with the rear 70 percent of the vane profile movable as a trailing-edge flap. Vane flap mechanical setting angles of 0 to 50 deg measured from the axial direction were possible, and performance parameters were determined over this range of angles. Turning angles followed a general trend obtained with Carter’s rule for accelerating cascades with the presently measured values tending to be lower than those obtained with Carter’s rule at higher setting angles. For large camber angles (greater than 35 deg) zero-incidence blade element total-pressure loss coefficients for the 50 percent passage location of the flapped vanes tested were higher than those that might have been obtained with a continously cambered vane row of the same solidity and camber.Copyright © 1970 by ASME

Effect of Reynolds number on overall performance of a 6-inch radial bladed centrifugal compressor

Abstract: Overall performance of centrifugal compressor over range of inlet pressures and corresponding Reynolds number