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Preliminary empirical design requirements for the prevention of tumbling of airplanes having no horizontal tails

Description: Report presenting an investigation of the design characteristics and loadings conducive to the tumbling of airplanes with no horizontal tails. Empirical design requirements based on model testings of 18 different configurations and an explanation of the phenomena of tumbling are provided.
Date: October 11, 1950
Creator: Bryant, Robert L.
Partner: UNT Libraries Government Documents Department

High-Subsonic Performance Characteristics and Boundary-Layer Investigations of a 12 10-Inch-Inlet-Diameter Conical Diffuser

Description: Performance and boundary-layer data were taken in a 12 degree 10-inch inlet-diameter conical diffuser of 2:1 exit- to inlet-area ratio. These data were taken for two inlet-boundary-layer conditions. The first condition was that of a thinner inlet boundary later (boundary-layer displacement thickness, delta* approximately equal to 0.034) produced by an inlet section approximately 1 inlet diameter in length between the entrance bell and the diffuser. The second condition was a thicker inlet boundary layer (delta* approximately equal to 0.120) produced by an additional inlet section length of approximately 6 diameters. Longitudinal static-pressure distributions were measured fro wall static orifices. Transverse total- and static-pressure surveys were made at the inlet and exit stations. Boundary-layer velocity distributions were measured at seven stations between the inlet and exit. These data were obtained for a Reynolds number (based on inlet diameter) range of 1 x 10(exp 6) to 3.9 x 10(exp 6). The corresponding Mach number range was from M = 0.2 to choking. At the maximum-power-available condition supersonic flow was obtained as far as 4.5 inches downstream from the diffuser inlet with a maximum Mach number of M approximately equal to 1.5. The total-pressure loss through the diffuser in percentage of inlet dynamic pressure was approximately 2.5 percent for the thinner inlet boundary later and 5.5 percent for the thicker inlet boundary later over the lower subsonic range. These valued increased with increasing flow rate- the values for the thicker inlet boundary later more than those for the thinner inlet boundary layer. The diffuser effectiveness, expressed as the ratio of the actual static-pressure rise to the ideal static-pressure rise, was about 85 percent for the thinner inlet boundary layer and about 67 percent for the thicker inlet boundary later in the lower subsonic range. These values decrease with increasing flow rate. Separated flow ...
Date: May 11, 1950
Creator: Little, B. H., Jr. & Wilbur, Stafford W.
Partner: UNT Libraries Government Documents Department

Calibration of instruments for measuring wind velocity and direction

Description: From Summary: "Signal Corps wind equipment AN/GMQ-1 consisting of a 3-cup anemometer and wind vane was calibrated for wind velocities from 1 to 200 miles per hour. Cup-shaft failure prevented calibration at higher wind velocities. The action of the wind vane was checked and found to have very poor directional accuracy below a velocity of 8 miles per hour. After shaft failure was reported to the Signal Corps, the cup rotors were redesigned by strengthening the shafts for better operation at high velocities. The anemometer with the redesigned cup rotors was recalibrated, but cup-shaft failure occurred again at a wind velocity of approximately 220 miles per hour."
Date: September 11, 1950
Creator: Vogler, Raymond D. & Pilny, Miroslav J.
Partner: UNT Libraries Government Documents Department

Preliminary flight investigation of the wing-dropping tendency and lateral-control characteristics of a 35 degree swept-wing airplane at transonic Mach numbers

Description: Report presenting results from a preliminary flight investigation on a swept-wing airplane of the lateral-control characteristics and wing-dropping tendency encountered at high Mach numbers. Measurements of aileron and rudder-control effectiveness are presented and used with estimated damping-in-roll characteristics and data from steady sideslips to approximate the variation of effective dihedral with Mach number.
Date: September 11, 1950
Creator: Rathert, George A., Jr.; Rolls, L. Stewart; Winograd, Lee & Cooper, George E.
Partner: UNT Libraries Government Documents Department

Preliminary flight investigation of the dynamic longitudinal-stability characteristics of a 35 degree swept-wing airplane

Description: Report presenting flight measurements of the dynamic longitudinal-stability characteristics of a 35 degree swept-wing airplane. The results indicated that a sharp reduction in damping at a Mach number of 0.92 with maximum damping occurred at Mach number of 0.88 and 0.94. Results regarding oscillation periods, damping coefficients, scatter, and number of cycles required for oscillations to damp to a certain amplitude are provided.
Date: December 11, 1950
Creator: Triplett, William C. & Van Dyke, Rudolph D., Jr.
Partner: UNT Libraries Government Documents Department

Flight measurements with the Douglas D-558-II (BuAero No. 37974) research airplane : determination of the aerodynamic center and zero-lift pitching-moment coefficient of the wing-fuselage combination by means of tail-load measurements in the Mach num

Description: Report presenting flight measurements of aerodynamic tail loads made on the Douglas D-558-II from which the variation with Mach number of the wing-fuselage aerodynamic center, static-longitudinal-stability parameter, the tail load per g, and the zero-lift wing-fuselage pitching-moment coefficient determined up to Mach number 0.87.
Date: July 11, 1950
Creator: Mayer, John P.; Valentine, George M. & Mayer, Geraldine C.
Partner: UNT Libraries Government Documents Department

Analytical determination of local surface heat-transfer coefficients for cooled turbine blades from measured metal temperatures

Description: Analytical methods are presented for the determination of local values of outside and inside heat-transfer coefficients and effective gas temperatures by use of turbine-blade-temperature measurements. The methods are derived for a number of configurations that can be applied to typical cooled-turbine-blade shapes as well as to other types of heat-transfer apparatus.
Date: August 11, 1950
Creator: Brown, W. Byron & Esgar, Jack B.
Partner: UNT Libraries Government Documents Department

Extension of boundary-layer heat-transfer theory to cooled turbine blades

Description: An equation for average heat transfer of a surface was derived when the boundary layer changed from laminar to turbulent. Influences on the heat transfer through a laminar boundary layer of Mach number, temperature ratio (gas temperature divided by wall temperature), and exponents of gas-property temperature relations were shown to be relatively small for air with Mach numbers less than 2 and temperature ratios between 1 and 4. Good agreement was obtained with experimental results from cylinders, an airfoil, and turbine blades.
Date: August 11, 1950
Creator: Brown, W. Byron & Donoughe, Patrick L.
Partner: UNT Libraries Government Documents Department

Altitude performance characteristics of tail-pipe burner with variable-area exhaust nozzle

Description: From Introduction: "Data are presented to show the effects of tail-pipe fuel-air ratio, altitude, and flight Mach number on tail-pipe-burner performance at rated engine speed and approximately constant turbine-outlet temperature. Operational characteristics of the tail-pipe burner and variable-area exhaust nozzle are also reported."
Date: August 11, 1950
Creator: Jansen, Emmert T. & Thorman, H. Carl
Partner: UNT Libraries Government Documents Department

Wind-tunnel investigation of a 1/6-scale model of the Bumblebee XPM missile at high subsonic speeds

Description: Report presenting the results of an investigation of a model of the Bumblebee XPM missile to determine the causes of booster-fin failures on full-scale missiles. Results indicated that failures of the fins were due to launching shoes which caused the missile to try at increasingly negative angles of attack as the Mach number increased.
Date: December 11, 1950
Creator: Nelson, Warren H.
Partner: UNT Libraries Government Documents Department

Effect of fuel volatility on altitude starting limits of a turbojet engine

Description: The effect of fuel volatility on altitude starting limits of an axial-flow-compressor-type turbojet engine was investigated using fuels with Reid vapor pressures of 1.1 and 5.4 pounds per square inch. At flight Mach numbers from 0.40 to 0.85, the AN-F-58 fuel allowed consistent windmilling at altitudes 2000 to 8000 feet higher than was obtained with the 1.1-pound Reid vapor pressure fuel. At a flight Mach number of 0.25, ignition could not be established at any altitude with the lower-volatility fuel.
Date: September 11, 1950
Creator: Wilsted, H. D. & Armstrong, J. C.
Partner: UNT Libraries Government Documents Department

Effects of the Lateral Oscillation of Fixing the Rudder and Reflexing the Flaps on the Bell X-1 Airplane

Description: Memorandum presenting flight tests made on the Bell X-1 airplane with the 10-percent-thick wing and the 8-percent-thick tail to evaluate the effects of fixing the rudder and changing the inclination of the principal axes of inertia. The data were obtained during power-off glides at altitudes between 32,000 and 16,000 feet.
Date: December 11, 1950
Creator: Drake, Hubert M.
Partner: UNT Libraries Government Documents Department

Calculated Performance of Nuclear Turbojet Powered Airplane at Flight Mach Number of 0.9

Description: "An analysis was made at flight Mach number of 0.9 to estimate performance of nuclear-energy-powered turbojet engine and optimum engine operating conditions and to determine gross weight and load-carrying capacity of airplane powered by such an engine. The size of airplane required to carry disposable load of 20,000 pounds was found to vary from approximately 300,000 to 900,000 pounds depending on assumptions. For a reactor tube-wall mean temperature of 2500 degrees R, turbine-inlet temperature of 2000 degrees R, reactor-free-flow-area ratio of 0.33, reactor-shielding-material specific gravity of 6.0, shielding thickness of 3.0 feet, and altitude of 30,000 feet, the airplane gross weight required to carry a 20,000 payload is 545,000 pounds" (p. 1).
Date: May 11, 1950
Creator: Doyle, Ronald B.
Partner: UNT Libraries Government Documents Department

Wind-tunnel investigation of a 1/6-scale model of the Bumblebee XPM missile at high subsonic speeds

Description: Report presenting an investigation of a model of the Bumblebee XPM missile to determine the causes of booster-fin failures for a range of Mach numbers and Reynolds numbers. The cause of fin failure was determined to be the launching shoes that caused the missiles to trim at increasingly negative angles of attack. Additional testing with wing spoilers and alternate booster fins was also conducted.
Date: December 11, 1950
Creator: Nelson, Warren H.
Partner: UNT Libraries Government Documents Department