Optimized turning-vane design for an intake elbow of an axial-flow compressor
Elbow turning vane design for high recovery and Uniform distribution at exit of 90 deg intake elbow of axial flow compressor
ELBOW↗
SEARCH · Search NASA
Results for “COMPRESSORS - RADIAL FLOW”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Analysis of Off-design Performance of a 16-stage Axial-flow Compressor with Various Blade Modifications
The over-all performance of a 16-stage axial-flow compressor was determined with various stator-blade resettings and a reduction in solidity of the rotor blades in the last three stages. It was shown that little control over the sudden change in slope of the surge-limit line at intermediate speeds was obtained with the blade modifications attempted, except that some change in speed at which the change in slope occurred could be effected by stator-blade resettings. Interstage data indicated that the severe surge limit at intermediate speeds was caused by stall of the inlet stage, which, because of stage interaction effects, resulted in a simultaneous decrease in performance of the following five or six stages. Stage data are presented which indicate the flow and pressure-ratio range over which each stage is required to operate at compressor speeds from 50 to 100 percent of design speed.
COMPRESSORS - AXIAL-FLOW↗
Blade selection for a modern axial-flow compressor
The procedures leading to successful design of an axial flow compressor are discussed. The three related approaches to cascade selection are: (1) experimental approach which relies on the use of experimental results from identical cascades to satisfy the velocity diagrams calculated, (2) a purely analytical procedure whereby blade shapes are calculated from the theoretical cascade and viscous flow equations, and (3) a semiempirical procedure which used experimental data together with the theoretically derived functional relations to relate the cascade parameters. Diagrams of typical transonic blade sections with uncambered leading edges are presented.
Wright, L. C.↗
Analysis of effect of basic design variables on subsonic axial-flow-compressor performance
A blade-element theory for axial-flow compressors has been developed and applied to the analysis of the effects of basic design variables such as Mach number, blade loading, and velocity distribution on compressor performance. A graphical method that is useful for approximate design calculations is presented. The relations among several efficiencies useful in compressor design are derived and discussed. The possible gains in useful operating range obtainable by the use of adjustable stator blades are discussed and a rapid approximate method of calculating blade-angle resettings is shown by an example. The relative Mach number is shown to be a dominant factor in determining the pressure ratio.
Sinnette, John T , Jr↗
Experimental evaluation of outer case blowing or bleeding of single stage axial flow compressor. Part I - Design of rotor and bleeding and blowing configurations
Rotor design to evaluate outer case blowing or bleeding of single stage axial flow compressor
BLOWING↗
Multiple over-all performance and rotating-stall characteristics of a 15-stage experimental axial-flow compressor at an intermediate speed
The 15-stage experimental axial-flow compressor was investigated at 78.5 percent of design speed, which falls in the region of the surge-limit line discontinuity. In this region indications of multiple characteristic curves of compressor operation had been found. On the basis of previous stage-matching analyses, these multiple performance characteristics appear to be the result of multiple-valued stage performance characteristics. At this speed of 78.5 percent, at least six separate characteristic performance curves were found, associated with five different numbers of rotating stall configurations, from zero to four stall zones. It was difficult in many cases to repeat a given performance curve by approaching the test speed in a similar manner, and many of the curves were not stable, the no-stall curve being the only definitely repeatable one. In some cases a jump from one curve to another took place at the surge point, while in others the change occurred within the usual limits of a conventional performance curve and without any sudden obvious changes in observed data. In general, as the number of zones in the rotating-stall pattern decreased, the maximum weight flow, maximum efficiency, and maximum pressure ratio of the resultant curves were increased. It appears, therefore, that multiple performance characteristics at the given speed are encountered in the region of the discontinuity of the surge line.
Lucas, James G↗
Program For Analysis Of Axial-Flow Compressors
CSPAN (Compressor SPanline ANalysis) computer program assists in design of axial-flow compressors. Enables design engineer to study relationships among number of stages, flow-path radii, gas velocities, flow angles, and resultant variation of compressor efficiency. Rapidly provides conceptual designs for preliminary design studies of air-breathing engines. Written in FORTRAN 77.
Glassman, Arthur J.↗
Computer program for definition of transonic axial-flow compressor blade rows
A method is presented for designing axial-flow compressor blading from blade elements defined on cones which pass through the blade-edge streamline locations. Each blade-element centerline is composed of two segments which are tangent to each other. The centerline and surfaces of each segment have constant change of angle with path distance. The stacking line for the blade elements can be leaned in both the axial and tangential directions. The output of the computer program gives coordinates for fabrication and properties for aeroelastic analysis for planar blade sections. These coordinates and properties are obtained by interpolation across conical blade elements. The program is structured to be coupled with an aerodynamic design program.
Crouse, J. E.↗
Performance of a tandem-rotor/tandem-stator conical-flow compressor designed for a pressure ratio of 3
A conical-flow compressor stage with a large radius change through the rotor was tested at three values of rotor tip clearance. The stage had a tandem rotor and a tandem stator. Peak efficiency at design speed was 0.774 at a pressure ratio of 2.613. The rotor was tested without the stator, and detailed survey data were obtained for each rotor blade row. Overall peak rotor efficiency was 0.871 at a pressure ratio of 2.952.
Wood, J. R.↗
Empirical mode constants for calculating frequencies of axial-flow compressor blades
The vibration characteristics of a group of axial-flow compressor blades of similar geometry were investigated. Empirical-mode constants were determined for the first three bending and torsional modes. A comparison of experimentally determined frequencies of a second group of blades with frequencies computed using these mode constants showed that the computed values were correct within 10 percent. The approximate limiting ratios of depth to chord and length to chord below which these constants could not be used to compute the natural frequencies were also found experimentally.
COMPRESSORS - STRESS AND VIBRATION↗
Enhanced capabilities and modified users manual for axial-flow compressor conceptual design code CSPAN
Modifications made to the axial-flow compressor conceptual design code CSPAN are documented in this report. Endwall blockage and stall margin predictions were added. The loss-coefficient model was upgraded. Default correlations for rotor and stator solidity and aspect-ratio inputs and for stator-exit tangential velocity inputs were included in the code along with defaults for aerodynamic design limits. A complete description of input and output along with sample cases are included.
Glassman, Arthur J.↗
Effect of Blade-surface Finish on Performance of a Single-stage Axial-flow Compressor
A set of modified NACA 5509-34 rotor and stator blades was investigated with rough-machine, hand-filed, and highly polished surface finishes over a range of weight flows at six equivalent tip speeds from 672 to 1092 feet per second to determine the effect of blade-surface finish on the performance of a single-stage axial-flow compressor. Surface-finish effects decreased with increasing compressor speed and with decreasing flow at a given speed. In general, finishing blade surfaces below the roughness that may be considered aerodynamically smooth on the basis of an admissible-roughness formula will have no effect on compressor performance.
COMPRESSORS - AXIAL FLOW↗
Aerodynamic Design of Axial-flow Compressors. Volume III
Chapters XI to XIII concern the unsteady compressor operation arising when compressor blade elements stall. The fields of compressor stall and surge are reviewed in Chapters XI and XII, respectively. The part-speed operating problem in high-pressure-ratio multistage axial-flow compressors is analyzed in Chapter XIII. Chapter XIV summarizes design methods and theories that extend beyond the simplified two-dimensional approach used previously in the report. Chapter XV extends this three-dimensional treatment by summarizing the literature on secondary flows and boundary layer effects. Charts for determining the effects of errors in design parameters and experimental measurements on compressor performance are given in Chapters XVI. Chapter XVII reviews existing literature on compressor and turbine matching techniques.
COMPRESSORS - PRESSURE RATIO↗
Effect of Reynolds number on overall performance of a 3.7-inch-diameter six-stage axial-flow compressor
A 9.4-centimeter (3.7-in.) diameter six-stage axial-flow compressor was tested in argon over a range of inlet pressures corresponding to a Reynolds number range of 30,600 to 160,000. The effect of Reynolds number on efficiency, pressure ratio, work input, maximum flow, and surge is shown. The Reynolds number effects are discussed in terms of changes in boundary-layer thickness, losses, and the resulting changes in throughflow velocity. Significant deviation was noted from the 0.2 power relation often used to express the variation of loss with Reynolds number.
Heidelberg, L. J.↗
Theoretical effect of inlet hub-tip-radius ratio and design specific mass flow on design performance of axial-flow compressors
Explore the source record for details and available documents.
COMPRESSORS - PRESSURE RATIO↗
Effect of Interstage Bleed on Rotating Stall and Blade Vibration in a 13-stage Axial-flow Compressor in a Turbojet Engine
The compressor case of a 13-stage axial-flow compressor was modified to incorporate air-bleed systems over the fifth and tenth rotor stages. Rotating stall-exited rotor-blade vibrations were measured in the first and second stages at 60 and 68 percent of rated speed, respectively. Either the fifth- or the tenth-stage bleeds satisfactorily eliminated the peak vibratory stresses.
Calvert, Howard F↗
Development of the Seeding System Used for Laser Velocimeter Surveys of the NASA Low-Speed Centrifugal Compressor Flow Field
Consideration is given to an atomizer-based system for distributing high-volume rates of polystyrene latex (PSL) seed material developed to support laser velocimeter investigations of the NASA Low-Speed Compressor flow field. Complete evaporation of the liquid carrier before the flow entering the compressor was of primary concern for the seeder system design. It is argued that the seed nozzle should incorporate a needle valve that can mechanically dislodge accumulated PSL seed material when the nozzle is turned off. Water is less expensive as the liquid carrier and should be used whenever adequate residence times are available to ensure complete evaporation. PSL agglomerates over time and needs to be mixed or blended before use. Arrangement of the spray nozzles needs to be adjustable to provide maximum seeding at the laser probe volume.
Wasserbauer, C. A.↗
Effect of several porous casing treatments on stall limit and on overall performance of an axial flow compressor rotor
Several geometrically different porous casings were tested with an axial-flow compressor rotor to determine their effects upon the rotor stall-limit line and overall performance. The tests were conducted using both uniform and nonuniform inlet-flow conditions. The rotor performance with the various casing treatments is compared with that obtained with a solid casing. The ability of the various casing treatments to displace the rotor stall-limit line to lower weight flows was observed. Significant stall-margin increases were obtained with several of the porous casings. Peak efficiencies with two of the porous casings were as high as or slightly higher than that obtained with solid casing.
Osborn, W. M.↗