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A Photographic Study of Freezing of Water Droplets Falling Freely in Air

Description: From Summary: "A photographic technique for investigating water droplets of diameter less than 200 microns falling freely in air at temperatures between 0 C and -50 C has been devised and used to determine: (1) The shape of frozen droplets, (2) The occurrence of collisions of partly frozen or of frozen and liquid droplets, and (3) The statistics on the freezing temperatures of individual free-falling droplets."
Date: February 25, 1952
Creator: Dorsch, Robert G. & Levine, Joseph
Partner: UNT Libraries Government Documents Department

Experimental investigation of effects of simulated nacelles and wing-root freedoms on supersonic flutter characteristics of a cambered, modified, swept, tapered wing

Description: Report presenting an investigation to determine the effects of simulated engine nacelles and wing-root freedoms on the flutter characteristics of a cambered, modified, swept, tapered, semispan wing through a range of Mach numbers. Wings were tested with and without nacelles and with the model restrained, free to roll, and free to translate in the vertical direction. Results regarding the effect of nacelles, flutter boundary, and effect of wing-mount freedom are provided.
Date: October 16, 1957
Creator: Hanson, Perry W.
Partner: UNT Libraries Government Documents Department

Experimental Investigation of Flutter and Divergence Characteristics of the Rocket-Motor Fin of the ASROC Missile

Description: Report presenting testing of models of rocket-motor fins of the ASROC missile for flutter and divergence in the supersonic flutter tunnel for a range of Mach numbers. Results indicate that both divergence of the overhung leading edge and flutter occur within the sea-level operating conditions of the missile at Mach numbers above 1.0. Results regarding the flutter boundary, type of flutter encountered, possible solutions to flutter problems, and possible effects of nondestructive type of flutter are provided.
Date: July 31, 1958
Creator: Levey, Gilbert M. & Hanson, Perry W.
Partner: UNT Libraries Government Documents Department

Investigation of Wingless Missile Configurations with Folding Controls and Low-Aspect-Ratio Stabilizing Surfaces

Description: Results regarding a wind-tunnel investigation of wingless missile configurations with cylindrical bodies and conical or hemispherical noses, extensible control surfaces aft of the nose, and tails consisting of eight low-aspect-ratio triangular or rectangular fins. Normal-force, axial-force, and pitching-moment coefficients were obtained for several control deflections for Mach numbers 1.2 and 1.9.
Date: September 17, 1958
Creator: Lazzeroni, Frank A.
Partner: UNT Libraries Government Documents Department

A Method for Prevention of Screaming in Rocket Engines

Description: From Summary: "Lateral and longitudinal combustion-pressure oscillations that occurred in screaming combustion of a 1000-pound-thrust rocket engine using white fuming nitric acid and JP-4 fuel as propellants were successfully prevented by means of longitudinal fins in the combustion chamber. Fin position was critical, and complete attenuation was achieved only when the fins were located in a zone approximately 8 to 16 inches from the injector. Fins located in other zones, that is, near the injector or far downstream from the injector, did not stop the oscillations."
Date: August 19, 1954
Creator: Male, Theodore & Kerslake, William R.
Partner: UNT Libraries Government Documents Department

Performance of an All-internal Conical Compression Inlet With Annular Throat Bleed at Mach Number 5.0

Description: Report presenting an investigation of an all-internal conical compression inlet with annular bleed at the throat at Mach number 5.0 and zero angle of attack. Results regarding the performance of the diffuser alone, a Pitot-pressure survey of the flow leaving the diffuser, total-pressure distribution, and inlet efficiencies are provided.
Date: August 6, 1958
Creator: Stitt, Leonard E. & Obery, Leonard J.
Partner: UNT Libraries Government Documents Department

Performance of an Inlet Having a Variable-angle Two-dimensional Compression Surface and a Fixed-geometry Subsonic Diffuser for Application to Reduced Engine Rotative Speeds- Mach Numbers 0.66, 1.5, 1.7, and 2.0

Description: Report presenting the performance of a two-dimensional side inlet with a technique of varying compression-surface angle while retaining a fixed-geometry diffuser at several Mach numbers and zero angle of attack. A 12 degree compression ramp was faired into the diffuser contour in this conventional manner. Results regarding the inlet flow field, application to reduced engine speeds, and a inlet performance with a sudden expansion in the diffuser are provided.
Date: January 30, 1958
Creator: Allen, John L.
Partner: UNT Libraries Government Documents Department

Full-scale, free-jet investigation of methods of improving outlet flow distribution in a side-inlet supersonic diffuser

Description: Report presenting a full-scale, free-jet investigation to determine the performance of a side-inlet supersonic diffuser designed for a flight Mach number of 2.75. Several internal modifications made to improve diffuser-outlet flow uniformity were also evaluated. Results regarding the general characteristics of the diffuser and effect of diffuser modifications on flow distribution are provided.
Date: March 28, 1955
Creator: Farley, John M. & Seashore, Ferris L.
Partner: UNT Libraries Government Documents Department

Determination of rate, area, and distribution of impingement of of waterdrops on various airfoils from trajectories obtained on the differential analyzer

Description: From Summary: "The trajectories of waterdrops in air flowing over airfoils are determined for three airfoil-angle-of-attack combinations using the differential analyzer to solve the differential equations of motion of the waterdrops. From these trajectories the rate of water impingement, the area of impingement, and the distribution of impingement are determined as functions of two dimensionless moduli. Comparisons are made of the rate of water impingement on these airfoils and the rate of water impingement on cylinders."
Date: February 16, 1949
Creator: Guibert, A. G.; Janssen, E. & Robbins, W. M.
Partner: UNT Libraries Government Documents Department

Design and performance of flight-type liquid-hydrogen heat exchanger

Description: Report presenting an investigation of a liquid-hydrogen fuel system developed to operate one of the turbojet engines in a twin-engine light bomber at an altitude of 50,000 feet and Mach number 0.75. The heat exchanger was evaluated in an altitude test chamber in conjunction with the complete aircraft fuel system. Results regarding calculated heat-exchanger performance, experimental heat-exchanger performance, and reliability are provided.
Date: August 19, 1957
Creator: Fenn, David B.; Braithwaite, Willis M. & Ordin, Paul M.
Partner: UNT Libraries Government Documents Department

Combustion of gaseous hydrogen at low pressures in a 35 degree sector of a 28-inch-diameter ramjet combustor

Description: Report presenting testing of gaseous hydrogen fuel burned in a connected-pipe combustor with a cross section equal to 35 degrees sector of a 28-inch diameter. Eleven shrouded fuel-injector configurations were used to obtain combustion data at specified high-altitude ramjet combustor conditions. Results regarding shroud air blockage, mixing tabs, higher equivalence-ratio burning, injector size, flameholder durability, burner length, combustion efficiency, and temperature profile are provided.
Date: April 22, 1958
Creator: Kerslake, William R.
Partner: UNT Libraries Government Documents Department

Analysis of rocket, ramjet, and turbojet engines for supersonic propulsion of long-range missiles. 3: Ramjet engine performance

Description: Report presenting ramjet engine performance data over a range of engine design variables to permit selection and evaluation of a ramjet engine configuration for a long-range supersonic missile. Results include engine thrust, drag, fuel consumption, area ratios, and weight, and are suitable for use in design studies of missiles incorporating either internally or externally mounted ramjet engines.
Date: August 5, 1954
Creator: Weber, Richard J. & Luidens, Roger W.
Partner: UNT Libraries Government Documents Department

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

Description: From Summary: "Procedures for applying these analytical methods to experimentally measured blade-metal temperatures are presented. Data are presented for the leading and trailing edge of a symmetrical water-cooled blade to illustrate the validity of the methods for those portions of the blade. In addition to the application to turbine blades, the methods can be applied to any heat-transfer apparatus having a profile that can be approximated by the shape discussed."
Date: April 10, 1950
Creator: Brown, W. Byron & Esgar, Jack B.
Partner: UNT Libraries Government Documents Department

Analysis of low-temperature nuclear-powered ramjet missile for high altitudes

Description: From Summary: "The reactor operating conditions were varied to enable selection of values giving a good compromise between low uranium investment and loss gross weight at each altitude and flight Mach number considered. The corresponding values of reactor and missile operating conditions are presented in the report."
Date: November 9, 1955
Creator: Rom, F. E. & Sams, E. W.
Partner: UNT Libraries Government Documents Department

Analysis of a liquid-metal turbine-propeller cycle for propulsion of low-speed nuclear- powered aircraft

Description: From Introduction: "The intermediate subsonic speed range is considered and the liquid-metal turbine-propeller cycle discussed in this report. In this report, compressor pressure ratio, heat-exchanger air-inlet Mach number, and turbine-inlet temperature were optimized for maximum engine net thrust per engine-plus-heat exchanger weight (minimum airplane gross weight) for a range of heat-exchanger effective wall temperature."
Date: May 27, 1952
Creator: Rom, F. E. & Wachtl, W. W.
Partner: UNT Libraries Government Documents Department

An Analysis of Air-turborocket Engine Performance Including Effects of Component Changes

Description: Report presenting analytical estimates of the thrust, efficiency, drag, and weight of the air-turborocket engine. The effects of changes in the engine components on design and off-design performance are emphasized. Results regarding the performance, effect of design parameters, effect of subsonic cruising Mach number, geometry variations, engine weight estimates, and comparison with turbojet engines are provided.
Date: April 6, 1956
Creator: Luidens, Roger W. & Weber, Richard J.
Partner: UNT Libraries Government Documents Department

Boundary-Layer-Transition Measurements in Full-Scale Flight

Description: Chemical sublimation has been employed for boundary-layer-flow visualization on the wings of a supersonic fighter airplane in level flight at speeds near a Mach number of 2.0. The tests have shown that laminar flow can be obtained over extensive areas of the wing with practical wing-surface conditions. In addition to the flow visualization tests, a method of continuously monitoring the conditions of the boundary layer has been applied to flight testing, using heated temperature resistance gages installed in a Fiberglas "glove" installation on one wing. Tests were conducted at speeds from a Mach number of 1.2 to a Mach number of 2.0, at altitudes from 35,000 feet to 56,000 feet. Data obtained at all angles of attack, from near 0 deg to near 10 deg, have shown that the maximum transition Reynolds number on the upper surface of the wing varies from about 2.5 x 10(exp 6) at a Mach number of 1.2 to about 4 x 10(exp 6) at a Mach number of 2.0. On the lower surface, the maximum transition Reynolds number varies from about 2 x 10(exp 6) at a Mach number of 1.2 to about 8 x 10(exp 6) at a Mach number of 2.0.
Date: July 28, 1958
Creator: Banner, Richard D.; McTigue, John G. & Petty, Gilbert, Jr.
Partner: UNT Libraries Government Documents Department

Experimental Investigation of Effects of Combustion-chamber Length and Inlet Total Temperature, Total Pressure, and Velocity on Afterburner Performance

Description: Report presenting an investigation of the effects of afterburner-inlet total temperature, total pressure, velocity, fuel-air ratio, and afterburner combustion-chamber length on afterburner performance and stability limits using a cylindrical afterburner installed in a duct test rig. The afterburner was investigated over a range of total temperature, total pressure, velocity, and afterburner fuel-air ratios.
Date: June 3, 1957
Creator: King, Charles R.
Partner: UNT Libraries Government Documents Department

Spark Ignition of Flowing Gases. 2: Effect of Electrode Parameters on Energy Required to Ignite a Propane-Air Mixture

Description: From Summary: "Research was conducted to determine the effect of the electrode parameters of spacing, configuration, and material' on the energy required for ignition of a flowing propane-air mixture. In addition, the data were used to indicate the energy distribution along the spark length and to confirm previous observations concerning the effect of spark duration on ignition energy requirements. The data were obtained with a mixture at a fuel-air ratio of 0.0835 (by weight), a pressure of 3 inches of mercury absolute, a temperature of 80 F, and a mixture velocity of 5 feet per second."
Date: December 18, 1951
Creator: Swett, Clyde C., Jr.
Partner: UNT Libraries Government Documents Department

Some Research on the Lift and Stability of Wing-Body Combinations

Description: The present paper summarizes and correlates broadly some of the research results applicable to fin-stabilized ammunition. The discussion and correlation are intended to be comprehensive, rather than detailed, in order to show general trends over the Mach number range up to 7.0. Some discussion of wings, bodies, and wing-body interference is presented, and a list of 179 papers containing further information is included. The present paper is intended to serve more as a bibliography and source of reference material than as a direct source of design information.
Date: July 2, 1959
Creator: Purser, Paul E. & Fields, E. M.
Partner: UNT Libraries Government Documents Department