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Investigation of Two-Stage Counterrotating Compressor. 3: Design of Second-Stage Rotor and Preliminary Over-All Performance

Description: At the design speed of a two-stage counterrotating compressor, an overall average pressure ratio of 4.3 was obtained at a specific weight flow of 27.2 pounds per second per square foot frontal area with an adiabatic efficiency of 0.75. Preliminary tests indicate that a weight-flow mismatching exists between the two rotors that causes the first rotor to operate at less than peak efficiency at design speed. At lower speeds, the first stage was forced to operate in the stalled region in single-stage tests. With the second rotor installed, no periodic rotating stall was observed, although random fluctations of similiar magnitude were noted.
Date: October 22, 1956
Creator: Wilcox, Ward W. & Wright, Linwood C.
Partner: UNT Libraries Government Documents Department

Analysis of stage matching and off-design performance of multistage axial-flow compressors

Description: From Introduction: "The present report is intended to give a qualitative picture of the operation of each stage of a multistage compressor over a range of actual operating conditions from 50 to 100 percent design speed and to point out some means of achieving improved off-design performance. The method used in the report is primarily analytical and is based on single-stage-performance results."
Date: June 27, 1952
Creator: Finger, Harold B & Dugan, James F , Jr
Partner: UNT Libraries Government Documents Department

Analysis of part-speed operation for high-pressure-ratio multistage axial-flow compressors

Description: From Introduction: "For the analysis reported herein, the same hypothetical 12-stage compressor discussed in reference 6 was chosen, and the effects of inlet-stage stall characteristics and stage interactions were estimated by arbitrary adjustment of the stall characteristics and stage interactions were estimated by arbitrary adjustment of the stalled characteristics of the individual stages."
Date: December 4, 1953
Creator: Benser, William A.
Partner: UNT Libraries Government Documents Department

An analytical investigation using aerodynamic limitations of several designs of high stage pressure ratio multistage compressors

Description: From Introduction: "As more quantitative information becomes available, more will be known of the maximum stage total-pressure ratios that can be used while maintaining acceptable efficiences and weight flows. Because quantitative knowledge is limited, the qualitative nature of limiting factors and trends are investigated herein."
Date: December 1951
Creator: Voit, Charles H. & Thomson, Arthur R.
Partner: UNT Libraries Government Documents Department

Analysis of transonic rotor-blade passage loss with hot-wire anemometers

Description: From Introduction: "This report presents data from measurements of the flow in a single-stage research compressor, which supports the model of reference 1. A calculated shock technique similar to that of reference 1 is incorporated with these experimental results. Another approach for estimating passage shock loss given a flow rate and blade geometry was reported in reference 2."
Date: June 5, 1958
Creator: Lewis, George W.; Tysl, Edward R. & Fessler, Theodore E.
Partner: UNT Libraries Government Documents Department

Effect of Various Blade Modifications in Performance of a 16-Stage Axial-flow Compressor. IV - Effect on Over-all Performance Characteristics of Decreasing Twelfth through Fifteenth Stage Stator-blade Angles 3 deg and Increasing Stator Angles in the Inlet Stages

Description: The performance of a 16-stage axial-flow compressor, in which two modifications of unloaded inlet stages were combined with loaded exit stages, has been determined. In the first modification the exit stages were loaded by decreasing the twelfth through fifteenth stage stator angles 3 deg. as compared with the blade angles in the original compressor, and the inlet stages were unloaded by increasing the blade angles the following amounts: guide vanes and first-stage stator, 6 deg; second- and third-stage stators, 4 deg.; and fourth-stage stators, 3 deg. The over-all performance of this configuration was compared with that of the compressor with the original blade angles. The peak efficiency was increased at all speeds below design and the weight flow was higher at speeds below 80 percent of design, the same at 80 percent of design, and lower at speeds abovce 80 percent of design. The maximum reduction in weight flow occurred at design speed. The surge limit line was higher at speeds between 75 and 90 percent of design when presented on a pressure ratio against weight flow basis. The second configuration was the same as the first with the exception that the second-, third-, and fourth-stage stator blade angles were the same as in the compressor with the original blade angles. A comparison of the performance of this configuration with that of the compressor with the original blade angles showed the same general trends of changes in performance as the first configuration. Comparisons were made of compressor configurations to show the effects upon the performance of decreased loading in the inlet stages. Below 75 percent of design speed, decreased loading results in increased weight flow and peak efficiency; above 80 percent of design speed, decreased loading in the inlet stages results in decreased weight flow and small changes in peak ...
Date: March 17, 1952
Creator: Hatch, James E. & Medeiros, Arthur A.
Partner: UNT Libraries Government Documents Department

Design and investigation of a transonic axial-flow compressor rotor with an inlet hub-tip radius ratio of essentially zero

Description: Report presenting an investigation of an axial-flow compressor rotor with an inlet hub-tip radius ratio of basically zero. Results regarding the radial distribution of total-pressure ratio and efficiency, measured pressure ratio at design speed, weight flow, and low-speed cascade data are provided.
Date: March 11, 1957
Creator: Westphal, Willard R. & Maynard, John W., Jr.
Partner: UNT Libraries Government Documents Department

Analysis of two-spool turboprop-engine characteristics

Description: From Introduction: "The purpose of this report is to present the results of an analytical investigation of the engine characteristics of two-spool engines with high over-all compressor pressure ratio (12.0 at design). Some of the turbine design problems encountered in a single-spool engine with current compressor pressure ratio (7.32 at design) were investigated in reference 1. The investigation was extended in reference 2 to cover the effect of mode of engine operation on the turbine design requirements and engine performance for a single-spool engine with current compressor pressure ratio."
Date: June 3, 1957
Creator: Davison, Elmer H
Partner: UNT Libraries Government Documents Department

Analysis of a form of peak holding control

Description: From Introduction: "The general objective of this report is a study of the characteristics of the described form of peak holding control. The control has not yet been used in experimental turbojet-engine study.This study is concerned with only one method of extracting the maximum amount of information from a peak output for the purpose of maintaining that peak. The criteria sought in this control process are: maintenance of peak average output, minimum duration of time in undesirable operation, quickness in response to command to reach peak condition, least amount of excursion in the undesirable region, and type of stability."
Date: March 30, 1956
Creator: Delio, G J
Partner: UNT Libraries Government Documents Department

Aerodynamic Design of Axial-Flow Compressors, Volume 2

Description: Available experimental two-dimensional-cascade data for conventional compressor blade sections are correlated. The two-dimensional cascade and some of the principal aerodynamic factors involved in its operation are first briefly described. Then the data are analyzed by examining the variation of cascade performance at a reference incidence angle in the region of minimum loss. Variations of reference incidence angle, total-pressure loss, and deviation angle with cascade geometry, inlet Mach number, and Reynolds number are investigated. From the analysis and the correlations of the available data, rules and relations are evolved for the prediction of the magnitude of the reference total-pressure loss and the reference deviation and incidence angles for conventional blade profiles. These relations are developed in simplified forms readily applicable to compressor design procedures.
Date: August 1, 1956
Partner: UNT Libraries Government Documents Department

Aerodynamic design of axial-flow compressors: Volume III

Description: 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.
Date: August 1, 1956
Creator: Johnsen, Irving A.; Bullock, Robert O.; Graham, Robert W.; Costilow, Eleanor L.; Huppert, Merle C.; Benser, William A. et al.
Partner: UNT Libraries Government Documents Department

Development of a Mobile Compressor and Utility Station

Description: Report issued by the U.S. Bureau of Mines on the development of a mobile compressor and utility station in the oil-shale mine near Rifle, Colorado during 1949. The report includes photographs and illustrations of the mobile station.
Date: July 1950
Creator: Wright, Fred D. & Ballinger, Homer J.
Partner: UNT Libraries Government Documents Department

An analysis of the potentialities of a two-stage counterrotating supersonic compressor

Description: From Introduction: "The supersonic axial-flow compressor, for example, appears to offer advantages of high stage pressure ratio and height weight flows (reference 1) but problems peculiar to this compressor type have accompanied its introduction. For high single-stage pressure ratios (>4) the problem of converting the high dynamic energy to useful pressure arises (reference 2). In addition, the high tip speeds and weight flows combine to create a difficult situation for the turbine designer."
Date: July 9, 1952
Creator: Wilcox, Ward W
Partner: UNT Libraries Government Documents Department

A technique applicable to the aerodynamic design of inducer-type multistage axial-flow compressors

Description: Report presenting a method for presenting the preliminary design calculation of high-pressure ratio, multistage, axial-flow compressors using the solid-body inducer-type design. Calculations are presented for various inlet hub-tip ratios, weight flows, and average pressure ratios per stage.
Date: March 1952
Creator: Savage, Melvyn & Beatty, Loren A.
Partner: UNT Libraries Government Documents Department

Apparent effect of inlet temperature on adiabatic efficiency of centrifugal compressors

Description: From Introduction: "The results of varying only Reynolds number for several equivalent tip speeds are presented and probable reasons for the apparent variation of adiabatic efficiency with inlet temperature are discussed."
Date: February 1948
Creator: Anderson, Robert J; Ritter, William K & Parsons, Shirley R
Partner: UNT Libraries Government Documents Department

Airplane superchargers

Description: Discussed here are the principles and operation of aircraft engine superchargers used to maintain and increase engine power as aircraft encounter decreases in the density of air as altitude rises. Details are given on the design and operation of the centrifugal compressors. A method is given for calculating the amount of power needed to drive a compressor. The effects of the use of a compressor on fuel system operation and design are discussed. Several specific superchargers that were in operation are described.
Date: May 1921
Creator: Noack, W. G.
Partner: UNT Libraries Government Documents Department

Investigation of blade-row flow distributions in axial-flow-compressor stage consisting of guide vanes and rotor-blade row

Description: A 30-inch tip-diameter axial-flow compressor stage was investigated with and without rotor to determine individual blade-row performance, interblade-row effects, and outer-wall boundary-layer conditions. Velocity gradients at guide-vane outlet without rotor approximated design assumptions, when the measured variation of leaving angle was considered. With rotor in operation, Mach number and rotor-blade effects changed flow distribution leaving guide vanes and invalidated design assumption of radial equilibrium. Rotor-blade performance correlated interpolated two-dimensional results within 2 degrees, although tip stall was indicated in experimental and not two-dimensional results. Boundary-displacement thickness was less than 1.0 and 1.5 percent of passage height after guide vanes and after rotor, respectively, but increased rapidly after rotor when tip stall occurred.
Date: November 28, 1950
Creator: Mahoney, John J.; Dugan, Paul D.; Budinger, Raymond E. & Goelzer, H. Fred
Partner: UNT Libraries Government Documents Department

Effects of obstructions in compressor inlet on blade vibration in 10-stage axial-flow compressor

Description: Report presenting a blade-vibration survey that was conducted during normal operation of a 10-stage axial-flow compressor powered by part of a complete jet engine. Strain-gage records were obtained from all stages during acceleration, deceleration, and constant-speed runs. Results regarding the inlet disturbances and damping characteristics are provided.
Date: February 13, 1950
Creator: Meyer, André J., Jr.; Calvert, Howard F. & Morse, C. Robert
Partner: UNT Libraries Government Documents Department

Investigation of an Experimental Supersonic Axial-Flow Compressor

Description: An investigation is in progress at the Langley Laboratory of the NACA to explore the possibilities of axial-flow compressors operating with supersonic velocities relative to the blade rows. The first phase of this investigation, a study of supersonic diffusers, has been reported. The second phase, an analysis of supersonic compressors, has also been reported. Preliminary calculations have shown that very high pressure ratios across a stage, together with somewhat increased mass flows, are possible with compressors which decelerate air through the speed of sound in their rotor blading. These performance characteristics are desirable in compressors for aircraft jet propulsion units, gas turbines, or superchargers. The third phase, presented here, is a preliminary experimental investigation of a supersonic compressor designed to produce a high pressure ratio in a single stage.
Date: August 7, 1947
Creator: Erwin, John R.; Wright, Linwood C. & Kantrowitz, Arthur
Partner: UNT Libraries Government Documents Department

Calibration of Air-Flow Meters for J33 Compressor Investigation

Description: Flow-metering devices used by the NACA and by the manufacturer of the J33 turbojet engine were calibrated together to determine whether an observed discrepancy in weight flow of approximately 4 percent for the two separate investigations might be due to the different devices used to meter air flow. A commercial adjustable orifice and a square-edge flat-plate orifice used by the NACA and a flow nozzle used by the manufacturer were calibrated against surveys across the throat of the nozzle. It was determined that over a range of weight flows from 18 to 45 pounds per second the average weight flows measured by the metering device used for the compressor test would be 0.70 percent lower than those measured by the metering device used in the engine tests and the probable variation about this mean would be +/- 0.39 percent. The very close agreement of the metering devices shows that the greater part of the discrepancy in weight flow is attributable to the effect of inlet pressure.
Date: August 16, 1948
Creator: Kovach, Karl & Withee, Joseph R., Jr.
Partner: UNT Libraries Government Documents Department

Experimental investigation of effects of design changes on performance of large-capacity centrifugal compressors

Description: Report presenting an investigation to determine the effects of several design changes on the performance of large-capacity, double-entry, centrifugal compressors. Four modifications of a turbojet engine compressor were operated over a range of equivalent impeller tip speeds an the compressor overall and component performances were determined. Results regarding the impeller performance, diffuser performance, and compressor performance are provided.
Date: March 2, 1951
Creator: Withee, Joseph R., Jr.; Kovach, Karl & Ginsburg, Ambrose
Partner: UNT Libraries Government Documents Department

Investigation of a 10-stage subsonic axial-flow research compressor 3: investigation of rotating stall, blade vibration and surge at low and intermediate compressor speeds

Description: Report presenting an investigation of rotating stall and surge at low and intermediate speeds conducted on a 10-stage subsonic axial-flow research compressor. Fluctuations of rotating stall and surge were detected by hot-wire anemometers and pressure transducers. Results regarding overall performance and rotating stall, rotating stall and blade vibration, surge, and discussion of surge are provided.
Date: May 18, 1953
Creator: Huppert, Merle C.; Costilow, Eleanor L. & Budinger, Ray E.
Partner: UNT Libraries Government Documents Department

Empirical mode constants for calculating frequencies of axial-flow compressor blades

Description: 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.
Date: April 23, 1948
Creator: Millenson, M. B. & Wilterdink, P. I.
Partner: UNT Libraries Government Documents Department