Study of the canard configuration with particular reference to transonic flight characteristics and low-speed characteristics at high lift (open access)

Study of the canard configuration with particular reference to transonic flight characteristics and low-speed characteristics at high lift

Report presenting a study of the flight characteristics of the canard configuration at transonic and supersonic speeds. Known problems concerning the low-speed characteristics of the canard are also investigated.
Date: November 16, 1949
Creator: Mathews, Charles W.
System: The UNT Digital Library
Critical Stress of Ring-Stiffened Cylinders in Torsion (open access)

Critical Stress of Ring-Stiffened Cylinders in Torsion

"A chart in terms of nondimensional parameters is presented for the theoretical critical stress in torsion of simply supported cylinders stiffened by identical equally spaced rings of zero torsional stiffness. The results are obtained by solving the equation of equilibrium by means of the Galerkin method. Comparison of the theoretical results with experimental results indicates that ring-stiffened cylinders buckle, on the average, at a buckling stress about 15 percent below the theoretical buckling stress" (p. 1).
Date: November 1949
Creator: Stein, Manuel; Sanders, J. Lyell, Jr. & Crate, Harold
System: The UNT Digital Library
Effect of tunnel configuration and testing technique on cascade performance (open access)

Effect of tunnel configuration and testing technique on cascade performance

"An investigation has been conducted to determine the influence of aspect ratio, boundary-layer control by means of slots and porous surfaces, Reynolds number, and tunnel end-wall condition upon the performance of airfoils in cascades. A representative compressor-blade section (the NACA 65-(12)(10) of aspect ratios of 1, 2, and 4 has been tested at low speeds in cascades with solid and with porous side walls. Two-dimensional flow was established in porous-wall cascades of each of the three aspect ratios tested; the flow was not two-dimensional in any of the solid-wall cascades" (p. 263).
Date: November 30, 1949
Creator: Erwin, John R. & Emery, James C.
System: The UNT Digital Library
Flight Investigations at High-Subsonic, Transonic, and Supersonic Speeds to Determine Zero-Lift Drag of Fin-Stabilized Bodies of Revolution having Fineness Ratios of 12.5, 8.91, and 6.04 and Varying Positions of Maximum Diameter (open access)

Flight Investigations at High-Subsonic, Transonic, and Supersonic Speeds to Determine Zero-Lift Drag of Fin-Stabilized Bodies of Revolution having Fineness Ratios of 12.5, 8.91, and 6.04 and Varying Positions of Maximum Diameter

Rocket-powered models were flown at high-subsonic, transonic, and supersonic speeds to determine the zero-lift drag of fin-stabilized parabolic bodies of revolution differing in fineness ratio and in position of maximum diameter. The present paper presents the results for fineness ratio 12.5, 8.91 and 6.04 bodies having maximum diameters located at stations of 20, 40, 60, and 80 percent of body length. All configurations had cut-off sterns and all had equal base, frontal, and exposed fin areas. For most of the supersonic-speed range models having their maximum diameters at the 60-percent station gave the lowest values of drag coefficient. At supersonic speeds, increasing the fineness ratio generally reduced the drag coefficient for a given position of maximum diameter.
Date: November 30, 1949
Creator: Hart, Roger G. & Katz, Ellis R.
System: The UNT Digital Library
On the Motions of an Oscillating System Under the Influence of Flip-Flop Controls (open access)

On the Motions of an Oscillating System Under the Influence of Flip-Flop Controls

"So-called flip-flop controls (also called "on-off-course controls") are frequently preferred to continuous controls because of their simple construction. Thus they are used also for the steering control of airplanes. Such a body possesses-even if one thinks, for instance, only of the symmetric longitudinal motion - three degrees of freedom so that a study of its motions under the influence of an intermittent control is at least lengthy. Thus, it is suggested that an investigation of the basic effect of such a control first be made on a system with one degree of freedom" (p. 1).
Date: November 1949
Creator: Flügge-Lotz, I. & Klotter, K.
System: The UNT Digital Library
Performance of Axial-Flow Supersonic Compressor of the XJ55-FF-1 Turbojet Engine. 4 - Analysis of Compressor Operation over a Range of Equivalent Tip Speeds from 801 to 1614 Feet Per Second (open access)

Performance of Axial-Flow Supersonic Compressor of the XJ55-FF-1 Turbojet Engine. 4 - Analysis of Compressor Operation over a Range of Equivalent Tip Speeds from 801 to 1614 Feet Per Second

"An investigation was conducted to determine the performance characteristics of the axial-flow supersonic compressor of the XJ55-FF-1 turbojet engine. An analysis of the performance of the rotor was made based on detailed flow measurements behind the rotor. The compressor apparently did not obtain the design normal-shock configuration in this investigation. A large redistribution of mass occurred toward the root of the rotor over the entire speed range; this condition was so acute at design speed that the tip sections were completely inoperative" (p. 1).
Date: November 18, 1949
Creator: Graham, Robert C. & Hartmann, Melvin J.
System: The UNT Digital Library
Two-Dimensional Potential Flows (open access)

Two-Dimensional Potential Flows

Contents include the following: Characteristic differential equations - initial and boundary conditions. Integration of the second characteristic differential equations. Direct application of Meyer's characteristic hodograph table for construction of two-dimensional potential flows. Prandtl-Busemann method. Development of the pressure variation for small deflection angles. Numerical table: relation between deflection, pressure, velocity, mach number and mach angle for isentropic changes of state according to Prandtl-Meyer for air (k = 1.405). References.
Date: November 1949
Creator: Schäefer, Manfred & Tollmien, W.
System: The UNT Digital Library
Rotationally Symmetric Potential Flows (open access)

Rotationally Symmetric Potential Flows

This paper includes the following topics: 1) Characteristic differential equations; 2) Treatment of practical examples; 3) First example: Diffuser; and 4) Second Example: Nozzle.
Date: November 1949
Creator: Schäefer, Manfred & Tollmien, W.
System: The UNT Digital Library
Hydrodynamic Qualities of a 1/10-Size Powered Dynamic Model of the XP5Y-1 Flying Boat in Smooth Water: Langley Tank Model 246, TED No. NACA DE 320 (open access)

Hydrodynamic Qualities of a 1/10-Size Powered Dynamic Model of the XP5Y-1 Flying Boat in Smooth Water: Langley Tank Model 246, TED No. NACA DE 320

"The hydrodynamic characteristics of a 1/10-size powered dynamic model of the XP5Y-1 flying boat were determined in Langley tank no. 1. Stable take-offs were possible at all practicable positions of the center of gravity and flap deflections. An increase in gross load from 123.5 to 150.0 pounds (21.5 percent) had only a slight effect on the stable range for take-off" (p. 1).
Date: November 15, 1949
Creator: Woodward, David R.; Weinstein, Irving & Whitaker, Walter E., Jr.
System: The UNT Digital Library
Measurement of Oil-Film Pressures in Journal Bearings under Constant and Variable Loads (open access)

Measurement of Oil-Film Pressures in Journal Bearings under Constant and Variable Loads

"In a study of journal bearings, the measurement of the oil-film strength produces some significant information. A new instrument is described by means of which the pressure of the oil film in bearings (under constant or alternating load) can be measured and recorded. With this device, the pressure distribution in the lubricating film of a bearing bushing was measured (under different operating conditions on a journal bearing) in the pulsator-bearing-testing machine" (p. 1).
Date: November 1949
Creator: Buske, A. & Rolli, W.
System: The UNT Digital Library
General Characteristics of a Airspeed System using Fuselage Static Vents on a Swept-Wing Airplane (open access)

General Characteristics of a Airspeed System using Fuselage Static Vents on a Swept-Wing Airplane

"Studies have been made by the NACA wing-flow method of the use of fuselage static orifices between the wing and tail of a swept-wing airplane for possible application to service airspeed installations. The tests were made at zero angle of attack. The results indicate that, although the maximum errors are large, these locations are usable from the consideration that the local Mach numbers at the locations studied are sensitive to variation of the true Mach number within the test Mach number range of 0.7 to 1.2" (p. 1).
Date: November 3, 1949
Creator: Johnston, J. Ford & O'Bryan, Thomas C.
System: The UNT Digital Library
Altitude performance and operational characteristics of 29-inch-diameter tail-pipe burner with several fuel systems and flame holders on J35 turbojet engine (open access)

Altitude performance and operational characteristics of 29-inch-diameter tail-pipe burner with several fuel systems and flame holders on J35 turbojet engine

From Summary: "An investigation of turbojet-engine thrust augmentation by means of tail-pipe burning has been conducted in the NACA Lewis altitude wind tunnel. Several fuel systems and flame holders were investigated in a 29-inch-diameter tail-pipe burner to determine the effect of fuel distribution and flame-holder design on tail-pipe-burner performance and operational characteristics over a range of simulated flight conditions. At an altitude of 5000 feet, the type of flame holder used had only a slight effect on the combustion efficiency."
Date: November 8, 1949
Creator: Conrad, E. William & Prince, William R.
System: The UNT Digital Library
Altitude-wind-tunnel investigation of J47 turbojet-engine performance (open access)

Altitude-wind-tunnel investigation of J47 turbojet-engine performance

From Introduction: "Data are presented in graphical form to show the engine performance over a range of altitudes from 5000 to 50,000 feet and flight Mach numbers from 0.21 to 0.97. Curves are presented to show the windmilling characteristics of the engine. All engine performance data obtained in the investigation are also presented in tabular form."
Date: November 15, 1949
Creator: Conrad, E. William & Sobolewski, Adam E.
System: The UNT Digital Library
Downwash in Vortex Region Behind Trapezoidal-Wing Tip at Mach Number 1.91 (open access)

Downwash in Vortex Region Behind Trapezoidal-Wing Tip at Mach Number 1.91

Report presenting the results of an experimental investigation to determine the downwash in the region of the trailing vortex behind a trapezoidal-wing tip in a supersonic stream. Results regarding the downwash at spanwise stations, downwash at chordwise stations, and wake survey are provided.
Date: November 10, 1949
Creator: Cummings, J. L.; Mirels, H. & Baughman, L. E.
System: The UNT Digital Library
Wing-tunnel investigation at low transonic speeds of the effects of number of wings on the lateral-control effectiveness of an RM-5 test vehicle (open access)

Wing-tunnel investigation at low transonic speeds of the effects of number of wings on the lateral-control effectiveness of an RM-5 test vehicle

Report presenting an investigation to determine the effects of number of wings on the aileron rolling effectiveness of an RM-5 test vehicle using the free-rolling wind-tunnel testing technique through a speed range to Mach number 0.9. The wings tested had neither taper nor sweepback and were equipped with full-span 20-percent-chord sealed and faired ailerons. Results indicated that increasing the number of wings resulted in a decrease in rolling effectiveness so that results obtained from the test of the three-wing model were closer to conventional-airplane-configuration results than the four-wing data.
Date: November 29, 1949
Creator: Johnson, Harold S.
System: The UNT Digital Library
Spin-Tunnel Investigation of the Jettisoning of External Fuel Tanks in Spins (open access)

Spin-Tunnel Investigation of the Jettisoning of External Fuel Tanks in Spins

"A spin-tunnel investigation has been made to determine the probability of external fuel tanks striking an airplane after being jettisoned in a spin. The investigation showed that for straight-wing fighter-type designs in any case in which jettisoning of tanks in a spin might aid spin recovery the tanks would probably clear all parts of the airplane" (p. 1).
Date: November 30, 1949
Creator: Berman, Theodore
System: The UNT Digital Library
Analytical determination of effect of water injection on power output of turbine-propeller engine (open access)

Analytical determination of effect of water injection on power output of turbine-propeller engine

From Introduction: "Water injection at the compressor inlet has been successfully used to increase the thrust of turbojet engines. References 1 and 2 indicate that the sea-level static thrust of a centrifugal-flow-type turbojet engine may be increased about 25 percent by use of liquid injection. Reference 3 indicates that greater thrust augmentation is possible at a compressor pressure ratio of 11 than of 4."
Date: November 3, 1949
Creator: Ross, Albert O. & Huppert, Merle C.
System: The UNT Digital Library
Model ditching investigation of the Douglas DC-4 and DC-6 airplanes (open access)

Model ditching investigation of the Douglas DC-4 and DC-6 airplanes

Report presenting the ditching characteristics of the Douglas DC-4 and DC-6 in a water tank. Dynamically similar models of 1/16 scale were used for the investigation, which was conducted in calm and rough water. The ditching characteristics and safest ditching procedures were determined by testing at various landing attitudes, speeds, and simulated conditions of damage.
Date: November 8, 1949
Creator: Fisher, Lloyd J. & Hoffman, Edward L.
System: The UNT Digital Library
Reduction of profile drag at supersonic velocities by the use of airfoil sections having a blunt trailing edge (open access)

Reduction of profile drag at supersonic velocities by the use of airfoil sections having a blunt trailing edge

Report presenting a preliminary theoretical and experimental investigation of the supersonic characteristics of blunt-trailing-edge airfoils. Results regarding the drag measurements at zero lift, measurements at angle of attack, and a general discussion of the theoretical and experimental results is provided.
Date: November 1, 1949
Creator: Chapman, Dean R.
System: The UNT Digital Library
Low-speed pressure-distribution and flow investigation for a large pitch and yaw range of three low-aspect-ratio pointed wings having leading edge swept back 60 degrees and biconvex sections (open access)

Low-speed pressure-distribution and flow investigation for a large pitch and yaw range of three low-aspect-ratio pointed wings having leading edge swept back 60 degrees and biconvex sections

Report presenting an investigation of pressure distributions and flow characteristics at low speed through a range of yaw and angle of attack through the stall for three small-scale low-aspect-ratio pointed wings with varying degrees of trailing-edge sweep. An effort was made to correlate pressure distributions with the strong conical vortex flow observed. Results regarding chordwise pressure distributions and flow characteristics, section lift characteristics at zero yaw, spanwise-load distributions, centers of pressure at zero yaw, and wing force and moment characteristics are provided.
Date: November 18, 1949
Creator: May, Ralph W., Jr. & Hawes, John G.
System: The UNT Digital Library
Altitude-wind-tunnel investigation of compressor performance on J47 turbojet engine (open access)

Altitude-wind-tunnel investigation of compressor performance on J47 turbojet engine

From Introduction: "The effects of variations in altitude, flight Mach number, and exhaust-nozzle-outlet area on the compressor performance characteristics are graphically presented. A complete tabulation of the compressor performance data is also presented."
Date: November 22, 1949
Creator: Prince, William R. & Jansen, Emmert T.
System: The UNT Digital Library
Vibration of loosely mounted turbine blades during service operation of a turbojet engine with centrifugal compressor and straight-flow combustion chambers (open access)

Vibration of loosely mounted turbine blades during service operation of a turbojet engine with centrifugal compressor and straight-flow combustion chambers

Report presenting an experimental investigation to determine the vibration characteristics of loosely mounted turbine blades during service operation of a turbojet engine. High-temperature strain gages were used to measure turbine-blade vibrations. Results regarding oscillograph records, critical speeds and frequencies, vibratory-stress levels, and effect of tightening the blade mount are provided.
Date: November 3, 1949
Creator: Morgan, W. C.; Kemp, R. H. & Manson, S. S.
System: The UNT Digital Library
Aerodynamic Characteristics of a Wing With Quarter-Chord Line Swept Back 45 Degrees, Aspect Ratio 6, Taper Ratio 0.6, and NACA 65A006 Airfoil Section (open access)

Aerodynamic Characteristics of a Wing With Quarter-Chord Line Swept Back 45 Degrees, Aspect Ratio 6, Taper Ratio 0.6, and NACA 65A006 Airfoil Section

Report discussing a wing-alone and wing-fuselage configuration with particular characteristics as part of a series of tests of wings using the transonic-bump test technique. Lift, drag, pitching moment, and root bending moment were obtained for the configurations. The effective downwash angles and dynamic-pressure characteristics in the tail region are also described.
Date: November 1, 1949
Creator: Goodson, Kenneth W. & Few, Albert G., Jr.
System: The UNT Digital Library
Estimation of the forces and moments acting on inclined bodies of revolution of high fineness ratio (open access)

Estimation of the forces and moments acting on inclined bodies of revolution of high fineness ratio

Report presenting a discussion of the aerodynamic forces and moments on inclined bodies of revolution. An approximate theory to allow for the effects of viscosity is developed and applied. Results regarding the variation of lift and pitching moment, and center of gravity are provided.
Date: November 14, 1949
Creator: Allen, H. Julian
System: The UNT Digital Library