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Experimental Investigation of an 0.8 Hub-Tip Radius-Ratio, Nontwisted-Rotor-Blade Turbine

Description: "An experimental investigation of a 0.8 hub-tip radius ratio, nontwisted-rotor-blade turbine designed for a stagnation-pressure ratio of 2.5 and an equivalent mean blade speed of 643 feet per second was made in a cold-air turbine with (a) nontwisted stator blades, and (b) twisted stator blades designed to maintain zero rotor-inlet incidence angles. Turbine efficiencies of the order of 0.85 at the design point were obtained with a nontwisted-rotor-blade turbine with a hub-tip radius ratio of 0.80. The turbine with the twisted stator blades gave higher efficiencies at the design point (of the order of 1.5 percentage points) than the turbine with the nontwisted stator blades" (p. 1).
Date: December 12, 1951
Creator: Silvern, David H. & Slivka, William R.
Partner: UNT Libraries Government Documents Department

Recent experimental flutter studies

Description: Report presenting some highlights of recent experimental studies of flutter at high speeds. Flutter problems have become more varied with the advent of transonic flight and importance of aeroelasticity, and the flutter field has merged with other aspect of aeroelasticity such as divergence and buffeting. The two main subjects of flutter, classical flutter and stall flutter, are explored in these studies.
Date: June 12, 1951
Creator: Regier, Arthur A. & Martin, Dennis J.
Partner: UNT Libraries Government Documents Department

Investigation of a 24-inch shock-in-rotor type supersonic compressor designed for simple radial equilibrium behind normal shock

Description: A 24-inch-diameter shock-in-rotor supersonic compressor rotor designed to obtain simple radial equilibrium behind the normal shock obtained a maximum total-pressure ratio of 2.02 at an adiabatic efficiency of 0.74 and a weight flow of 61.5 pounds per second at design speed. Although this design method considerably reduced the radial forces, there was no apparent reduction in the radial forces, there was no apparent reduction in the radial redistribution of mass flow over the radial redistribution obtained in the previous investigation. This investigation indicates that the shock boundary-layer interaction pattern and associated effects have a very large effect on the radial redistribution of mass flow through the shock-in-rotor supersonic-compressor rotor.
Date: December 12, 1951
Creator: Lown, Harold & Hartmann, Melvin J.
Partner: UNT Libraries Government Documents Department

A Method for the Design of Sweptback Wings Warped to Produce Specified Flight Characteristics at Supersonic Speeds

Description: Memorandum presenting a method for designing a wing to be self-trimming at a given set of flight conditions. The spanwise distribution of load on the wing is made to be approximately elliptical, in an effort to maintain low wing drag. The procedure is illustrated using several examples.
Date: September 12, 1951
Creator: Tucker, Warren A.
Partner: UNT Libraries Government Documents Department

Flow Separation Ahead of a Blunt Axially Symmetric Body at Mach Numbers 1.76 to 2.10

Description: "The pressure distribution and drag were determined for a spherical-nosed axially symmetric body with thin projecting rods at Mach numbers of 1.76, 1.93, and 2.10. The upstream projection distance of the rods was varied over a wide range to study changes in the character of the flow separation and to determine the variation of drag and pressure distribution with tip projection. Drag coefficients between 0.18 and 0.30 were obtained for most tip projections at each Mach number" (p. 1).
Date: December 12, 1951
Creator: Moeckel, W. E.
Partner: UNT Libraries Government Documents Department

Effect of angle of incidence of second-stage vane assembly on third-stage compressor-blade vibration and engine performance

Description: Strain-gages were used to measure blade vibrations causing failures in the third stage of a production 11-stage axial-flow compressor. After the serious third-stage vibration was detected, a series of investigations were conducted with second-stage vane assemblies of varying angles of incidence. Curves presented herein show the effect of varying the angle of incidence of second-stage vane assembly on third-stage rotor-blade vibration amplitude and engine performance. A minimum vibration amplitude was obtained without greatly affecting the engine performance with a second-stage vane assembly of 9deg. greater angle of incidence than the assembly normally furnished with the engine.
Date: June 12, 1951
Creator: Meyer, André J., Jr. & Calvert, Howard F.
Partner: UNT Libraries Government Documents Department

Control Performance of General Electric Fuel and Torque Regulator Operating on T31-3 Turbine-Propeller Engine in Sea-Level Test Stand

Description: A .General Electric fuel and torque regulator was tested in conjunction with a T31-3 turbine-propeller engine in the sea-level static test stand at the NACA Lewis laboratory. The engine and control were operated over the entire speed range: 11,000 rpm, nominal flight idle, to 13,000 rpm, full power. Steady-state and transient data were recorded and are presented with a description of the four control loops being used in the system. Results of this investigation indicated that single-lever control operation was satisfactory under conditions of test. Transient data presented showed that turbine-outlet temperature did overshoot maximum operating value on acceleration but that the time duration of overshoot did not exceed approximately 1 second. This temperature limiting resulted from a control on fuel flow as a function of engine speed. Speed and torque first reached their desired values 0.4 second from the time of change in power-setting lever position. Maximum speed overshoot was 3 percent.
Date: July 12, 1951
Creator: Oppenheimer, Frank L. & Lazar, James
Partner: UNT Libraries Government Documents Department

Generalization of Turbojet and Turbine-Propeller Engine Performance in Windmilling Condition

Description: Windmilling characteristics of several turbojet and turbine-propeller engines were investigated individually over a wide range of flight conditions in the NACA Lewis altitude wind tunnel. A study was made of all these data and windmilling performance of gas turbine engines was generalized. Although internal-drag, air-flow, and total-pressure-drop parameters were generalized to a single curve for both the axial-flow type engines and another for the centrifugal-flow engine. The engine speed, component pressure changes, and windmilling-propeller drag were generalized to single curves for the two turbine-propeller-type engines investigated. By the use of these curves the windmilling performance can be estimated for axial-flow type gas turbine engines similar to the types investigated over a wide range of flight conditions.
Date: December 12, 1951
Creator: Wallner, Ewis E. & Welna, Henry J.
Partner: UNT Libraries Government Documents Department

Investigation at Mach number 1.91 of side and base pressure distributions over conical boattails without and with jet flow issuing from base

Description: Experimental side and blade pressure distributions over a series of conical boattails without and with jet flow from the base are presented at a Mach number of 1.91. For the case of no jet flow the methods of characteristics and linearized theory are shown to overpredict the side pressure drag. A semi-empirical theory is presented to predict the effect of boattail angle on base pressure. With the boattail extending to a sharp edge at the nozzle exit, the over-pressure jet is shown to decrease the side pressure drag. Presence of an annular base may eliminate the effect of the jet on the side pressure drag, but the jet effect on the base pressure drag may greatly increase or decrease the total boattail drag.
Date: September 12, 1951
Creator: Cortright, Edgar M., Jr. & Schroeder, Albert H.
Partner: UNT Libraries Government Documents Department

Large-Scale Flight Measurements of Zero-Lift Drag at Mach Numbers from 0.90 to 1.95 of an Arrow Wing in Combination with a Small Body

Description: Report presenting a flight investigation at high subsonic, transonic, and supersonic speeds and at high Reynolds numbers to determine the zero-lift drag of an arrow wing-body combination and of the body without the wing. Results regarding the drag coefficient, Reynolds number, and normal-force coefficient against Mach number are provided.
Date: January 12, 1951
Creator: Gillespie, Warren, Jr. & Arbic, Richard G.
Partner: UNT Libraries Government Documents Department

The effect of end plates, end struts, and depth of submergence on the characteristics of a hydrofoil

Description: Report presenting an investigation into the effect of end plates and end-mounted struts on the lift-drag ratios of a hydrofoil at several speeds and Reynolds numbers that were all above the limiting speed of wave propagation. Information about the lift-drag ratio, effective aspect ratio, and comparison of the results versus theoretical calculations is included.
Date: April 12, 1951
Creator: Wadlin, Kenneth L.; Fontana, Rudolph E. & Shuford, Charles L., Jr.
Partner: UNT Libraries Government Documents Department

Characteristics throughout the subsonic speed range of a plane wing and of a cambered and twisted wing, both having 45 degrees of sweepback

Description: Report presenting a wind-tunnel investigation of two semispan wing models with 45 degrees of sweepback, an aspect ratio of 5, and a taper ratio of 0.565. One wing had no camber or twist while the other was cambered for a design lift coefficient of 0.4 and twisted to relieve loading at the tip. Results regarding the plane wing, cambered and twisted wing, wing-body combinations, effect of camber and twist, effect of fences, effect of surface roughness, and lift-drag ratio are provided.
Date: July 12, 1951
Creator: Johnson, Ben H., Jr. & Shibata, Harry H.
Partner: UNT Libraries Government Documents Department

Water landing investigation of a hydro-ski model at beam loadings of 18.9 and 4.4

Description: Report presenting an investigation of water landings in the impact basin with a model with a flat rectangular planing surface, a pulled-up bow, and a simulated landing wheel. Runs were made at several wave conditions, trim ranges, flight-path angles, and beam loadings. The results were found to be applicable in predicting loads and motions exhibited by a flat rectangular ski during impact with a water surface.
Date: September 12, 1951
Creator: Batterson, Sidney A.
Partner: UNT Libraries Government Documents Department

Lift, drag, and pitching moment of low-aspect-ratio wings at subsonic and supersonic speeds: twisted and cambered triangular wing of aspect ratio 2 with NACA 0003-63 thickness distribution

Description: This report presents the results of an investigation to ascertain the lift, drag, and pitching moment of a wing-body combination having a triangular wing of aspect ratio 2 with NACA 0003-63 thickness distribution in streamwise planes and twisted and cambered for a nearly elliptical span load distribution. Results are shown for Mach numbers from 0.60 to 0.90 and from 1.30 to 1.70 at Reynolds numbers of 3.0 million and 7.5 million.
Date: June 12, 1951
Creator: Hall, Charles F. & Heitmeyer, John C.
Partner: UNT Libraries Government Documents Department

Horizontal-tail effectiveness and downwash surveys for two 47.7 degree sweptback wing-fuselage combinations with aspect ratios of 5.1 and 6.0 at a Reynolds number of 6.0 x 10(exp 6)

Description: Report presenting an experimental investigation of the effectiveness of a horizontal tail on two 47.7 degree sweptback wing-fuselage combinations of aspect ratios 5.1 and 6.0. Various combinations of components were tested, including leading-edge flaps, drooped-nose, split flaps, and double slotted flaps, in addition to the flaps-neutral configuration. The primary purpose of the study was to determine the longitudinal stability characteristics of these wings in combination with the fuselage and tail and to determine if the tail is effective in overcoming the unstable variations in pitching moment prior to maximum lift.
Date: January 12, 1951
Creator: Salmi, Reino J.
Partner: UNT Libraries Government Documents Department

Altitude investigation of 16 flame-holder and fuel-system configurations in tail-pipe burner

Description: From Introduction: "The data obtained for each configuration are presented in a manner to show the effects of fuel distribution and flame-holder design on net thrust, specific fuel consumption, exhaust-gas temperature, combustion efficiency, operable range of tail-pipe-burner fuel-air ratios, and maximum altitude limit."
Date: December 12, 1951
Creator: Grey, Ralph E.; Krull, H. G. & Sargent, A. F.
Partner: UNT Libraries Government Documents Department

Considerations on a large hydraulic jet catapult

Description: Report presenting a survey of various types of catapults in connection with the problem of accelerating a large car along a track to a speed of 150 miles per hour. A hydraulic jet catapult seems to be the best-suited for the purpose, and various types of design problems are examined.
Date: April 12, 1951
Creator: Joyner, Upshur T. & Horne, Walter B.
Partner: UNT Libraries Government Documents Department

Velocity and temperature fields in circular jet expanding from choked nozzle into quiescent air

Description: The Mach number and temperature profiles in jets expanding from convergent and convergent-divergent nozzles are presented for several values of nozzle-exit pressure ratio. The effects of jet temperature, Reynolds number, and humidity on jet spreading are briefly evaluated. The results indicated that the downstream Mach number profiles for a heated jet are slightly narrower than those for a unheated jet, whereas the downstream temperature profiles were unaffected by nozzle temperature change, and that the effects of Reynolds number and humidity were negligible.
Date: July 12, 1951
Creator: Rousso, Morris D. & Kochendorfer, Fred D.
Partner: UNT Libraries Government Documents Department

Experimental Evaluation by Thermodynamic Methods of Work Input to a Centrifugal Compressor Operating With Water Injection

Description: Memorandum presenting a thermodynamic method of determining the work input to a centrifugal compressor operating with water injection. The method was used to compute the work input to a double-entry centrifugal compressor, which was operated at a design equivalent impeller speed over a range of inlet-water ratios and varying weight flow.
Date: January 12, 1951
Creator: Kovach, Karl; Beede, William L. & Hamrick, Joseph T.
Partner: UNT Libraries Government Documents Department

Investigations of Slot Configurations for Film-Cooled Turbine Blades by Flow Visualization Methods

Description: Memorandum presenting an investigation on the effectiveness of different slot configurations, which uses the method of making the flow of the cooling air visible. Two methods were used for this purpose: one utilized the traces caused by a reaction between pain spread over the blade surface and a gas mixed with the cooling air, while the second utilized smoke mixed with the cooling air to make it visible. A continuous slot was found to give the best coverage of the cooling-air film.
Date: January 12, 1951
Creator: Eckert, E. R. G.; Jackson, Thomas W. & Francisco, Allen C.
Partner: UNT Libraries Government Documents Department

Tensile Fracturing Characteristics of Several High-Temperature Alloys as Influenced by Orientation in Respect to Forging Direction

Description: Memorandum presenting the effects of specimen-axis orientation with respect to forging direction on the true stress-strain curves and the fracturing characteristics at room temperature of forged and subsequently heat-treated billets of alloys 16-25-6, S-816, and Inconel X. Results regarding plastic properties and fracture properties are provided.
Date: February 12, 1951
Creator: Brown, W. F., Jr.; Schwartzbart, H. & Jones, M. H.
Partner: UNT Libraries Government Documents Department

Experimental Investigation of Air-Cooled Turbine Blades in Turbojet Engine. 7: Rotor-Blade Fabrication Procedures

Description: "An experimental investigation was conducted to determine the cooling effectiveness of a wide variety of air-cooled turbine-blade configurations. The blades, which were tested in the turbine of a - commercial turbojet engine that was modified for this investigation by replacing two of the original blades with air-cooled blades located diametrically opposite each other, are untwisted, have no aerodynamic taper, and have essentially the same external profile. The cooling-passage configuration is different for each blade, however" (p. 1).
Date: September 12, 1951
Creator: Long, Roger A. & Esgar, Jack B.
Partner: UNT Libraries Government Documents Department