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Altitude-Wind-Tunnel Investigation of a 4000-Pound-Thrust Axial-Flow Turbojet Engine, Part 1, Performance and Windmilling Drag Characteristics

Description: From Summary: "The results of altitude-wind-tunnel tests conducted to determine the performance of an axial-flow-type 4000-pound-thrust turbojet engine for a range of pressure altitudes from 5000 to 40,000 feet and ram pressure ratios from 1.02 to 1.86 are presented and the experimental and analytical methods employed are discussed. By means of suitable generalizing factors applied to the measured performance data, curves were obtained from which the engine performance at any altitude for a given ram pressure ratio can be estimated. The data presented include the windmilling drag characteristics of the turbojet engine for the ranges of altitudes and ram pressure ratios covered by the performance data."
Date: August 3, 1948
Creator: Fleming, William A.
Partner: UNT Libraries Government Documents Department

Altitude-Wind-Tunnel Investigation of a 4000-Pound-Thrust Axial-Flow Turbojet Engine. 2 - Operational Characteristics

Description: From Summary: "An investigation was conducted in the Cleveland altitude wind tunnel to determine the operational characteristics of an axial flow-type turbojet engine with a 4000-pound-thrust rating over a range of pressure altitudes from 5,000 to 50,000 feet, ram pressure ratios from 1.00 to 1.86, and temperatures from 60 deg to -50 deg F. The low-flow (standard) compressor with which the engine was originally equipped was replaced by a high-flow compressor for part of the investigation. The effects of altitude and airspeed on such operating characteristics as operating range, stability of combustion, acceleration, starting, operation of fuel-control systems, and bearing cooling were investigated."
Date: August 6, 1948
Creator: Fleming, William A.
Partner: UNT Libraries Government Documents Department

Preliminary results of natural icing of an axial-flow turbojet engine

Description: Report presenting a flight investigation in natural icing conditions to determine the effect of ice formations on the performance of an axial-flow turbojet engine. Results regarding the tail-pipe temperature, engine jet thrust, and characteristics of ice formation are provided. No general conclusions can be reached from the data because the icing condition was relatively light.
Date: August 6, 1948
Creator: Acker, Loren W.
Partner: UNT Libraries Government Documents Department

The effects of yawing thin pointed wings at supersonic speeds

Description: From Summary: "An approximate relation is derived for the surface velocity potential of thin pointed wings at supersonic speeds when they are contained within the Mach cone from the vertex. This relation is applied to obtain the pressure distributions, the lift and drag coefficients, the center of pressure, and the rolling moments as a function of angle of yaw for the delta wing. Theoretical curves are presented for a Mach number of the square root of 2 to illustrate the relations."
Date: September 1947
Creator: Evvard, John C.
Partner: UNT Libraries Government Documents Department

Distribution of wave drag and lift in the vicinity of wing tips at supersonic speeds

Description: From Summary: "The point-source-distribution method of calculating the aerodynamic coefficients of thin wings at supersonic speeds was extended to include the effect of the region between the wing boundary and the foremost Mach wave from the wing leading edge. The effect of this region on the surface velocity potential has been determined by an equivalent function, which is evaluated over a portion of the wing surface. In this manner, the effect of angles of attack and yaw as well as the asymmetry of top and bottom wing surfaces may be calculated."
Date: July 1947
Creator: Evvard, John C.
Partner: UNT Libraries Government Documents Department

The determination of elastic stresses in gas-turbine disks

Description: Report presenting a method for the calculation of elastic stresses in symmetrical disks typical of those of a high-temperature gas turbine. Illustrative examples are presented to demonstrate how to treat solid disks, disks with central holes, and disks constructed of a single material or two or more welded materials.
Date: May 1947
Creator: Manson, S. S.
Partner: UNT Libraries Government Documents Department

A linearized solution for time-dependent velocity potentials near three-dimensional wings at supersonic speeds

Description: Report presenting a source-distribution method for deriving a solution for the time-dependent surface velocity potential of thin finite wings at supersonic speeds. It is illustrated by evaluating the upwash over the tip of an arbitrary-plan-boundary wing with a supersonic and subsonic leading edge.
Date: September 1948
Creator: Evvard, John C.
Partner: UNT Libraries Government Documents Department

Theoretical distribution of lift on thin wings at supersonic speeds (An extension)

Description: Report presenting a derivation of a point-source method based on the linearized theory for obtaining the pressure coefficient on thin wings at supersonic speeds. The analysis is continued to formulate the velocity potential for regions influenced by so-called subsonic trailing edges.
Date: May 1948
Creator: Evvard, John C.
Partner: UNT Libraries Government Documents Department

Comparative performance of two vaneless diffusers designed with different rates of passage curvature for mixed-flow impellers

Description: Report presenting an investigation of the effect of diffuser performance of the passage curvature of two vaneless diffusers designed with a 6 degree equivalent-cone divergence angle along a logarithmic-spiral path in combination with two mixed-flow impellers. The peak of overall adiabatic efficiency is compared with the corresponding diffuser efficiency. Results regarding the variation of diffuser efficiency with load-coefficient parameter and peak overall adiabatic efficiencies and corresponding diffuser efficiencies of the two compressors are provided.
Date: November 1947
Creator: Barina, Frank J.
Partner: UNT Libraries Government Documents Department

Flight investigation of the heat requirements for ice prevention on aircraft windshields

Description: Report presenting a flight investigation conducted to establish the heat requirements for ice prevention on aircraft windshields mounted on the forebody of an airplane at several angles. Electrically heated windshields were used in order to provide accurate measuring of heat input to the windshield. Results regarding the quantity of heat provided, amount of water collection, ideal windshield angle, ranges in airplane velocity, and icing conditions are provided.
Date: September 5, 1947
Creator: Kleinknecht, Kenneth S.
Partner: UNT Libraries Government Documents Department

Calculation of compressible flows past aerodynamic shapes by use of the streamline curvature

Description: "A simple approximate method is given for the calculation of isentropic irrotational flows past symmetrical airfoils, including mixed subsonic-supersonic flows. The method is based on the choice of suitable values for the streamline curvature in the flow field and the subsequent integration of the equations of motion. The method yields limiting solutions for potential flow. The effect of circulation is considered" (p. 1).
Date: June 1947
Creator: Perl, W.
Partner: UNT Libraries Government Documents Department

The optical system of the NACA 400,000-frame-per-second motion-picture camera

Description: Report presenting the optical principle of the NACA ultrahigh-speed camera. Simplified sketches are included illustrating the optical principle and main design features of the camera, but without minor design details. A detailed description of the camera is provided as well as some sample photographs taken with the camera.
Date: August 1947
Creator: Miller, Cearcy D.
Partner: UNT Libraries Government Documents Department

Ice protection of turbojet engines by inertia separation of water 1: alternate-duct system

Description: Aerodynamic and icing investigations of internal water-inertia separation inlets designed to prevent automatically entrance of large quantities of water into a turbojet engine in icing conditions was conducted on a one-half scale model. A simplified analytical approach to the design of internal water-inertia separation inlets is included. Results show that in order to be effective in preventing screen and guide-vane icing for an inlet of this type, a ram-pressure recovery of 75 percent was attained at design inlet-velocity ratio in an icing condition. For nonicing operation, ram-pressure recovery is comparable to direct-ram inlet.
Date: May 28, 1948
Creator: von Glahn, Uwe
Partner: UNT Libraries Government Documents Department

Design and performance of experimental axial-discharge mixed-flow compressor 2: performance of impeller

Description: Report presenting an analysis of an axial-discharge mixed-flow compressor designed to combine the compactness, reliability, and wide operating range of a mixed-flow compressor with the high flow capacity per unit of frontal area that characterizes the axial-flow compressor. The primary objective of this design was to maximize the flow capacity for a predetermined pressure ratio. Results regarding the flow distribution at the impeller inlet, flow distribution at the impeller outlet, and impeller performance are provided.
Date: August 12, 1948
Creator: Wilcox, Ward W.
Partner: UNT Libraries Government Documents Department

Lead susceptibility of paraffins, cycloparaffins, and olefins

Description: "General relationships for the lead susceptibilities of paraffins, cycloparaffins, and olefins are presented. Methods are described by which the lead response may be estimated for these hydrocarbon classes, whether the lead response is indicated by octane number, critical compression ratio, or indicated mean effective pressure as limited by knock" (p. 1).
Date: May 1943
Creator: Barnett, Henry C.
Partner: UNT Libraries Government Documents Department

Knocking combustion observed in a spark-ignition engine with simultaneous direct and Schlieren high-speed motion pictures and pressure records

Description: Simultaneous direct and Schlieren photographs at 40,000 frames per second and correlated pressure records were taken of knocking combustion in a special spark-ignition engine to ascertain the intensity of certain end-zone reactions previously noted from Schlieren photography alone. A violent propagated homogeneous autoignition, or a similar phenomenon, previously observed, was again observed. The pressure records show autoignition of varying violence before the passage of a probable detonation wave. Extensive autoignition without occurrence of gas vibrations was seen in one explosion.
Date: 1948
Creator: Osterstrom, Gordon E.
Partner: UNT Libraries Government Documents Department

Determination of Stress-Rupture Parameters for Four Heat-Resisting Alloys

Description: Stress-rupture data for four heat-resisting alloys are analyzed according to equations of the theory of rate processes. A method for determining the four parameters of structure and composition is demonstrated and the four parameters are determined for each of the alloys: forged S816, cast S816, cast S590, and cast Vitallium. It is concluded that parameters can be determined for an alloy provided sufficient reliable experimental data are available.
Date: August 25, 1947
Creator: Lidman, William G.
Partner: UNT Libraries Government Documents Department

X-ray diffraction investigation of minor phases of 20 high-temperature alloys

Description: Report presenting the use of x-ray diffraction methods to identify the minor phases present in 20 high-temperature alloys in current use. The minor phases were noted in seven of the 20 alloys. A description of the relation of the alloys to one another and their chemical properties are provided.
Date: July 1948
Creator: Rosenbaum, B. M.
Partner: UNT Libraries Government Documents Department

Investigation of the Aerodynamic and Icing Characteristics of a Recessed Fuel Cell Vent Assembly 1: Rear Wall Vent Tube Mounting

Description: An investigation conducted in the icing research tunnel on a ramp type recessed fuel cell vent assembly to determine its aerodynamic, rain, and icing characteristics. Although the vent-tube openings are located in the region of maximum ramp pressure, vent-tube static pressures are marginal for a low flight speed.
Date: March 29, 1948
Creator: Ruggeri, Robert S.
Partner: UNT Libraries Government Documents Department

Investigation of the aerodynamic and icing characteristics of a recessed fuel cell vent assembly 3: NACA flush-inlet-type vent

Description: An investigation conducted in the icing research tunnel to determine aerodynamic and icing characteristics of two flush-inlet-type fuel cell vent installations. The vent tubes were mounted in two different locations in the two installations. The vents were aerodynamically investigated to obtain vent-tube static-pressure differentials and pressure surveys as a function of tunnel-air velocity and angle of attack.
Date: April 23, 1948
Creator: Ruggeri, Robert S.
Partner: UNT Libraries Government Documents Department

Theoretical analysis of the performance of a supersonic ducted rocket

Description: Report presenting calculated performance characteristics of a ducted rocket with gasoline and liquid oxygen as the fuel mixture and with a mass flow of 1 slug per second. Evaluations of net thrust, frontal area, thrust per unit frontal area, and specific fuel consumption are given for all of the flight conditions under which it might operate.
Date: February 13, 1948
Creator: Hensley, Reece V.
Partner: UNT Libraries Government Documents Department

Ice protection of turbojet engines by inertia separation of water 3: annular submerged inlets

Description: Aerodynamic and icing studies were conducted on a one-half-scale model of an annular submerged inlet for use with axial-flow turbojet engines. Pressure recoveries, screen radial-velocity profiles, circumferential mass-flow variations, and icing characteristics were determined at the compressor inlet. In order to be effective in maintaining water-free induction air, the inlet gap must be extremely small and ram-pressure recoveries consequently are low, the highest achieved being 65 percent at inlet-velocity ratio of 0.86. All inlets exhibited considerable screen icing. Severe mass-flow shifts occurred at angles of attack.
Date: June 8, 1948
Creator: von Glahn, Uwe
Partner: UNT Libraries Government Documents Department

Ice protection of turbojet engines by inertia separation of water 2: single-offset-duct system

Description: Investigation of a single-offset-duct system designed to prevent entrance of water into a turbojet engine was conducted on a half-scale nacelle model. An investigation was made to determine ram-pressure recovery and radial velocity profiles at the compressor section and icing characteristics of such a duct system. At a design inlet velocity of 0.77, the maximum ram-pressure recovery attained with effective water-separating inlet was 77 percent, which is considerably less than attainable with a direct-ram inlet. Continuous heating of the accessory-housing surface would be required for inlets that have a small ice storage space.
Date: June 8, 1948
Creator: von Glahn, Uwe
Partner: UNT Libraries Government Documents Department