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Flight Comparison of Performance and Cooling Characteristics of Exhaust-Ejector Installation with Exhaust-Collector-Ring Installation (open access)

Flight Comparison of Performance and Cooling Characteristics of Exhaust-Ejector Installation with Exhaust-Collector-Ring Installation

Flight and ground investigations have been made to compare an exhaust-ejector installation with a standard exhaust-collector-ring installation on air-cooled aircraft engines in a twin-engine airplane. The ground investigation allowed that, whereas the standard engine would have overheated above 600 horsepower, the engine with exhaust ejectors cooled at take-off operating conditions at zero ram. The exhaust ejectors provided as much cooling with cowl flaps closed as the conventional cowl flaps induced when full open at low airspeeds. The propulsive thrust of the exhaust-ejector installation was calculated to be slightly less than the thrust of the collector-ring-installation.
Date: February 14, 1947
Creator: Acker, Loren W. & Kleinknecht, Kenneth S.
Object Type: Report
System: The UNT Digital Library
Investigations of Compression Shocks and Boundary Layers in Gases Moving at High Speed (open access)

Investigations of Compression Shocks and Boundary Layers in Gases Moving at High Speed

The mutual influences of compression shocks and friction boundary layers were investigated by means of high speed wind tunnels.Schlieren optics provided a clear picture of the flow phenomena and were used for determining the location of the compression shocks, measurement of shock angles, and also for Mach angles. Pressure measurement and humidity measurements were also taken into consideration.Results along with a mathematical model are described.
Date: January 1947
Creator: Ackeret, J.; Feldmann, F. & Rott, N.
Object Type: Report
System: The UNT Digital Library
Tests of a Horizontal-Tail Model through the Transonic Speed Range by the NACA Wing-Flow Method (open access)

Tests of a Horizontal-Tail Model through the Transonic Speed Range by the NACA Wing-Flow Method

"A 1/12-scale model of a horizontal tail of a fighter airplane was tested through the transonic speeds in the high-speed flow over an airplane wing, the surface of which served as a reflection plane for the model. Measurements of lift, elevator-hinge moment, angle of attack, and elevator angle were made in the Mach number range from 0.75 to 1.04 for elevator deflections ranging from 10 degrees to minus 10 degrees, and for angles of attack of minus 1.2 degrees, 0.4 degrees, and 3.4 degrees. The equipment used to measure the hinge moments of the model proved to be unsatisfactory, and for this reason the hinge-moment data are considered to be only qualitative" (p. 1).
Date: April 11, 1947
Creator: Adams, Richard E. & Silsby, Norman S.
Object Type: Report
System: The UNT Digital Library
Effects of Combinations of Aspect Ratio and Sweepback at High Subsonic Mach Numbers (open access)

Effects of Combinations of Aspect Ratio and Sweepback at High Subsonic Mach Numbers

Report discussing an investigation to determine the effects of sweepback and low aspect ratio on the aerodynamic characteristics of a wing at high subsonic Mach numbers. Tests were performed at aspect ratios of 2, 3, and 5 and sweepback angles of 0, 30, and 45 degrees. Generally, sweepback and low aspect ratio were found to both delay and lessen the effects of compressibility.
Date: June 4, 1947
Creator: Adler, Alfred A.
Object Type: Report
System: The UNT Digital Library
Drag Measurements of a 34 Degree Swept-Forward and Swept-Back NACA 65-009 Airfoil of Aspect Ratio 2.7 as Determined by Flight Tests at Supersonic Speeds (open access)

Drag Measurements of a 34 Degree Swept-Forward and Swept-Back NACA 65-009 Airfoil of Aspect Ratio 2.7 as Determined by Flight Tests at Supersonic Speeds

Report presenting the results of flight testing to determine the zero-lift drag of an NACA 65-009 airfoil at a specified aspect ratio. The results are compared to previous testing of unswept and swept-back arrangements. The swept-forward and swept-back airfoils were found to produce lower values of zero-drag lift than the unswept airfoil.
Date: February 20, 1947
Creator: Alexander, Sidney R.
Object Type: Report
System: The UNT Digital Library
Drag Measurements of a Swept-Back Wing Having Inverse Taper as Determined by Flight Tests at Supersonic Speeds (open access)

Drag Measurements of a Swept-Back Wing Having Inverse Taper as Determined by Flight Tests at Supersonic Speeds

Report discussing the results of flight tests to determine the drag at zero lift of a swept-back wing of inverse taper using an NACA 65-009 airfoil. The data was compared to untapered wings with a similar degree of sweepback. The tapered wing was found to have a lower drag coefficient than the 34-degree swept-back untapered wing but a higher drag coefficient than the 45-degree swept-back untapered wing.
Date: April 8, 1947
Creator: Alexander, Sidney R.
Object Type: Report
System: The UNT Digital Library
Drag Measurements of Symmetrical Circular-Arc and NACA 65-009 Rectangular Airfoils Having an Aspect Ratio of 2.7 as Determined by Flight Tests at Supersonic Speeds (open access)

Drag Measurements of Symmetrical Circular-Arc and NACA 65-009 Rectangular Airfoils Having an Aspect Ratio of 2.7 as Determined by Flight Tests at Supersonic Speeds

Report discussing testing to determine the drag characteristics at zero lift of a wing with a circular-arc airfoil section with a maximum thickness of 9 percent chord. The results were compared to previous testing on an NACA 65-009 airfoil. It was found that the NACA airfoil had lower drag coefficients than the circular-arc airfoil tested in this experiment.
Date: March 7, 1947
Creator: Alexander, Sidney R.
Object Type: Report
System: The UNT Digital Library
Results of Tests to Determine the Effect of a Conical Windshield on the Drag of a Bluff Body at Supersonic Speeds (open access)

Results of Tests to Determine the Effect of a Conical Windshield on the Drag of a Bluff Body at Supersonic Speeds

Tests to evaluate the effect of a conical windshield on the drag of a bluff body at supersonic speeds were performed for the following configurations: a sharp nose fuselage with stabilizing fins,a blunt nose fuselage with a hemispherical shape, and a blunt nose fuselage with a conical point. Results of the drag coefficient are described at Mach 1.0 and the greatest Mach number of 1.37.
Date: January 14, 1947
Creator: Alexander, Sidney R.
Object Type: Report
System: The UNT Digital Library
Drag characteristics of rectangular and swept-back NACA 65-009 airfoils having aspect ratios of 1.5 and 2.7 as determined by flight tests at supersonic speeds (open access)

Drag characteristics of rectangular and swept-back NACA 65-009 airfoils having aspect ratios of 1.5 and 2.7 as determined by flight tests at supersonic speeds

Report presenting tests to determine the effects of sweepback angle and aspect ratio on the drag of an NACA 65-009 airfoil at supersonic speeds. The results indicated that for the range of Mach numbers investigated, increasing the sweepback angle and decreasing the aspect ratio reduced the value of the wing drag coefficient.
Date: February 24, 1947
Creator: Alexander, Sidney R. & Katz, Ellis
Object Type: Report
System: The UNT Digital Library
Flight Tests to Determine the Effect of Length of a Conical Windshield on the Drag of a Bluff Body at Supersonic Speeds (open access)

Flight Tests to Determine the Effect of Length of a Conical Windshield on the Drag of a Bluff Body at Supersonic Speeds

Flight tests were conducted to determine the effect of length of a conical windshield on the drag of a bluff body moving at supersonic speeds. A comparison is made between results obtained and results of previous drag tests of body-windshield combinations.The effect of increasing the length of the windshield is discussed.
Date: January 29, 1947
Creator: Alexander, Sidney R. & Katz, Ellis
Object Type: Report
System: The UNT Digital Library
Flight Tests to Determine the Effect of Taper on the Zero-Lift Drag of Wings at Low Supersonic Speeds (open access)

Flight Tests to Determine the Effect of Taper on the Zero-Lift Drag of Wings at Low Supersonic Speeds

Report presenting the results of tests to determine the effect of taper on the zero-lift drag of wings of constant exposed aspect ratio at low supersonic speeds. Findings indicated that maximum thickness, leading-edge, and trailing-edge sweep are all important in determining the drag coefficient of a tapered wing.
Date: July 13, 1947
Creator: Alexander, Sidney R. & Nelson, Robert L.
Object Type: Report
System: The UNT Digital Library
The Effect of Compressibility on the Growth of the Laminar Boundary Layer on Low-Drag Wings and Bodies (open access)

The Effect of Compressibility on the Growth of the Laminar Boundary Layer on Low-Drag Wings and Bodies

Report presenting a consideration of the development of the laminar boundary layer in a compressible fluid. Formulas are given for determining the boundary-layer thickness and the boundary-layer Reynolds number, which is a measure of the boundary-layer stability, for airfoils and bodies of revolution.
Date: July 1947
Creator: Allen, H. Julian & Nitzberg, Gerald E.
Object Type: Report
System: The UNT Digital Library
The interaction of boundary layer and compression shock and its effect upon airfoil pressure distributions (open access)

The interaction of boundary layer and compression shock and its effect upon airfoil pressure distributions

Report presenting an investigation of the mechanism of interaction of compression shock with boundary layer. Shockless pressure distributions at supercritical Mach numbers were found to be accounted for by a marked thickening of the boundary layer for some distance ahead of a shock wave.
Date: April 10, 1947
Creator: Allen, H. Julian; Heaslet, Max A. & Nitzberg, Gerald E.
Object Type: Report
System: The UNT Digital Library
GAS COOLED PEBBLE PILES (open access)

GAS COOLED PEBBLE PILES

None
Date: August 1, 1947
Creator: Amorosi, A.
Object Type: Report
System: The UNT Digital Library
An Investigation at Low Speed of a Large-Scale Triangular Wing of Aspect Ratio Two 1: Characteristics of a Wing Having a Double-Wedge Airfoil Section With Maximum Thickness at 20-Percent Chord (open access)

An Investigation at Low Speed of a Large-Scale Triangular Wing of Aspect Ratio Two 1: Characteristics of a Wing Having a Double-Wedge Airfoil Section With Maximum Thickness at 20-Percent Chord

Report presenting an investigation of the low-speed characteristics of a 25-foot span triangular wing with an aspect ratio of 2. the airfoil section of the wing was a symmetrical double wedge with 5-percent maximum thickness at 20-percent chord. Results regarding the longitudinal characteristics, lateral characteristics, and directional characteristics are provided.
Date: November 13, 1947
Creator: Anderson, Adrien E.
Object Type: Report
System: The UNT Digital Library
An Investigation at Low Speed of a Large-Scale Triangular Wing of Aspect Ratio Two 2: The Effect of Airfoil Section Modifications and the Determination of the Wake Downwash (open access)

An Investigation at Low Speed of a Large-Scale Triangular Wing of Aspect Ratio Two 2: The Effect of Airfoil Section Modifications and the Determination of the Wake Downwash

Report presenting a study of the characteristics of a large-scale triangular wing to include the effects of section modifications. The wing in this report is the same as the one in the previous report but features various degrees of rounding of the wing leading edge and wing maximum thickness rather than having sharp edges. Results regarding the effects of airfoil section modifications, visible trailing vortices, and surveys in the extended chord plane are provided.
Date: December 10, 1947
Creator: Anderson, Adrien E.
Object Type: Report
System: The UNT Digital Library
Wind Tunnel Development of Means to Alleviate Buffeting of the North American XP-82 Airplane at High Speeds (open access)

Wind Tunnel Development of Means to Alleviate Buffeting of the North American XP-82 Airplane at High Speeds

"This report presents the results of wind-tunnel tests of a 0.22-scale model of the North American XP-82 airplane with several modifications designed to reduce the buffeting of the airplane. The effects of various modifications on the air flow over the model are shown by means of photographs of tufts. The drag, lift, and pitching-moment coefficients of the model with several of the modifications are shown" (p. 1).
Date: January 9, 1947
Creator: Anderson, Joseph L.
Object Type: Report
System: The UNT Digital Library
An Investigation of the Effect of Blade Curvature on Centrifugal-Impeller Performance (open access)

An Investigation of the Effect of Blade Curvature on Centrifugal-Impeller Performance

Note presenting an investigation of three centrifugal impellers, the same except for angular blade curvature, to determine the effect of the distribution of blade loading on impeller performance. Results regarding impeller efficiency, energy addition and pressure ratio, flow characteristics, and operating range are provided.
Date: May 1947
Creator: Anderson, Robert J.; Ritter, William K. & Dildine, Dean M.
Object Type: Report
System: The UNT Digital Library
Half-Scale Model Tests on the Three Quarter Wave R.F. System for the 184-inch Frequency Modulated Cyclotron (open access)

Half-Scale Model Tests on the Three Quarter Wave R.F. System for the 184-inch Frequency Modulated Cyclotron

Performance curves and test results on a half scale model of the radio frequency system designed to accelerate protons in the Berkeley 184-inch cyclotron are presented. This report is a sequel to K. R. Mackenzie's report on the three quarter wave radio frequency system for frequency modulated cyclotrons.
Date: December 30, 1947
Creator: Anderson, Robert L.
Object Type: Report
System: The UNT Digital Library
Determination of Coupled Modes and Frequencies of Swept Wings by Use of Power Series (open access)

Determination of Coupled Modes and Frequencies of Swept Wings by Use of Power Series

"A solution is presented for the coupled modes and frequencies of swept wings mounted on a fuselage. The energy method is used in conjunction with power series to obtain the characteristic equations for both symmetrical and asymmetrical vibration. A numerical example which is susceptible to exact solution is presented, and the results for the exact solution and the solution presented in this paper show excellent agreement" (p. 1).
Date: October 20, 1947
Creator: Anderson, Roger A.
Object Type: Report
System: The UNT Digital Library
Flight Measurements of the Flying Qualities of a Lockheed P-80A Airplane (Army No. 44-85099): Lateral- and Directional-Stability and Control Characteristics (open access)

Flight Measurements of the Flying Qualities of a Lockheed P-80A Airplane (Army No. 44-85099): Lateral- and Directional-Stability and Control Characteristics

"This report contains the flight-test results of the lateral and directional-stability and control phase (including tests with wing-tip tanks) of a general flying-qualities investigation of the Lockheed P-80A airplane (Army No. 44-85099). These tests were conducted at indicated airspeeds up to 494 miles per hour (0.691 Mach number) at low altitude and up to 378 miles per hour (0.816 Mach number) at high altitude. These tests showed that the flying qualities of the airplane were for the most part in accordance with the requirements of the Army Air Forces Stability and Control Specifications" (p. 1).
Date: October 24, 1947
Creator: Anderson, Seth B. & Cooper, George E.
Object Type: Report
System: The UNT Digital Library
Flight Measurements of the Flying Qualities of a Lockheed P-80A Airplane (Army No. 44-85099) - Stalling Characteristics (open access)

Flight Measurements of the Flying Qualities of a Lockheed P-80A Airplane (Army No. 44-85099) - Stalling Characteristics

This report contains the flight-test results of the stalling characteristics measured during the flying-qualities investigation of the Lockheed P-8OA airplane (Army No. 44-85099). The tests were conducted in straight and turning flight with and without wing-tip tanks. These tests showed satisfactory stalling characteristics and adequate stall warning for all configurations and conditions tested.
Date: December 4, 1947
Creator: Anderson, Seth B. & Cooper, George E.
Object Type: Report
System: The UNT Digital Library
Flight Measurements of the Flying Qualities of a Lockheed P-80A Airplane (Army No. 44-85099): Longitudinal-Stability and -Control Characteristics (open access)

Flight Measurements of the Flying Qualities of a Lockheed P-80A Airplane (Army No. 44-85099): Longitudinal-Stability and -Control Characteristics

This report contains the flight-test results of the longitudinal-stability and -control phase of a general flying qualities investigation of the Lockheed P-80A airplane (Army No. 44-85099). The tests were conducted at indicated airspeeds up to 530 miles per hour (0.76 Mach number) at low altitude and up to 350 miles per hour (0.82) Mach number) at high altitude. These tests showed that the flying qualities of the airplane were in accordance with the requirements of the Army Air Forces Stability and Control Specification except for excessive elevator control forces in maneuvering flight and the inadequacy of the longitudinal trimming control at low airspeeds.
Date: July 1, 1947
Creator: Anderson, Seth B.; Christofferson, Frank E. & Clousing, Lawrence A.
Object Type: Report
System: The UNT Digital Library
Analyses of Arizona, California, Idaho, Nevada and Oregon Coals (open access)

Analyses of Arizona, California, Idaho, Nevada and Oregon Coals

Technical paper issued by the Bureau of Mines over analyses of coals from many western states. The characteristics of the coals found in each state are discussed in detail. This paper includes tables, and maps.
Date: 1947
Creator: Andrews, David A.; Hendricks, Thomas A. & Huddle, John W.
Object Type: Report
System: The UNT Digital Library