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Acoustic radiation from two-dimensional rectangular cutouts in aerodynamic surfaces

Description: From Introduction: "The experiments in high-speed flow showed that an intense, high-frequency acoustic radiation is an essential feature of the problem. Consequently, a study of the acoustic field (involving schlieren observations and frequency and intensity measurements) was undertaken. This report presents the salient features of the study, which was mainly exploratory."
Date: August 1955
Creator: Krishnamurty, K
Partner: UNT Libraries Government Documents Department

Acoustic, thrust, and drag characteristics of several full-scale noise suppressors for turbojet engines

Description: From Introduction: " Considerable analytical and experimental research has been done to find means of reducing the noise levels of the turbojet transports. Noise levels can be decreased by engine redesign to reduce the jet-exit velocity (ref. 1), proper flight-climb techniques (ref. 2), and the use of noise-suppression exhaust nozzles (refs. 3 to 5). The present report is concerned with the last method."
Date: April 1958
Creator: Ciepluch, Carl C; North, Warren J; Coles, Willard D & Antl, Robert J
Partner: UNT Libraries Government Documents Department

Acoustical treatment for the NACA 8- by 6-foot supersonic propulsion wind tunnel

Description: From Introduction: "This report presents results of a research and engineering program performed during the first half of 1950 that resulted in an acoustical treatment for the 8- by 6-foot supersonic wind tunnel at the Lewis Flight Propulsion Laboratory."
Date: June 1955
Creator: Beranek, Leo L; Labate, Samuel & Ingard, Uno
Partner: UNT Libraries Government Documents Department

Acoustics of a nonhomogeneous moving medium.

Description: Report discussing theoretical basis of the acoustics of a moving nonhomogeneous medium. Experiments that illustrate or confirm some of the theoretical explanation or derivation of these acoustics are also included.
Date: February 1956
Creator: Blokhintsev, D I
Partner: UNT Libraries Government Documents Department

An active particle diffusion theory of flame quenching for laminar flames / Dorothy M. Simon and Frank E. Belles

Description: An equation for quenching distance based on the destruction of chain carriers by the surface is derived. The equation expresses the quenching distance in terms of the diffusion coefficients and partial pressures of the chain carriers and gas phase molecules, the efficiency of the surface as a chain breaker, the total pressure of the mixture, and a constant which depends on the geometry of the quenching surface. Quenching distances measured by flashback for propane-air flames are shown to be consistent with the mechanism. The derived equation is used with the lean inflammability limit and a rate constant calculated from burning velocity data to estimate quenching distances for propane-air (hydrocarbon lean) flames satisfactorily.
Date: March 4, 1952
Creator: Simon, Dorothy M & Belles, Frank E
Partner: UNT Libraries Government Documents Department

Adaptation of a Cascade Impactor to Flight Measurement of Droplet Size in Clouds

Description: A cascade impactor, an instrument for obtaining: the size distribution of droplets borne in a low-velocity air stream, was adapted for flight cloud droplet-size studies. The air containing the droplets was slowed down from flight speed by a diffuser to the inlet-air velocity of the impactor. The droplets that enter the impactor impinge on four slides coated with magnesium oxide. Each slide catches a different size range. The relation between the size of droplet impressions and the droplet size was evaluated so that the droplet-size distributions may be found from these slides. The magnesium oxide coating provides a permanent record. of the droplet impression that is not affected by droplet evaporation after the. droplets have impinged.
Date: September 18, 1951
Creator: Levine, Joseph & Kleinknecht, Kenneth S.
Partner: UNT Libraries Government Documents Department

Adaptation of Combustion Principles to Aircraft Propulsion, Volume 1, Basic Considerations in the Combustion of Hydrocarbon Fuels with Air

Description: The report summarizes source material on combustion for flight-propulsion engineers. First, several chapters review fundamental processes such as fuel-air mixture preparation, gas flow and mixing, flammability and ignition, flame propagation in both homogenous and heterogenous media, flame stabilization, combustion oscillations, and smoke and carbon formation. The practical significance and the relation of these processes to theory are presented. A second series of chapters describes the observed performance and design problems of engine combustors of the principal types. An attempt is made to interpret performance in terms of the fundamental processes and theories previously reviewed. Third, the design of high-speed combustion systems is discussed. Combustor design principles that can be established from basic considerations and from experience with actual combustors are described. Finally, future requirements for aircraft engine combustion systems are examined.
Date: April 1, 1955
Creator: Barnett, Henry C. & Hibbard, Robert R.
Partner: UNT Libraries Government Documents Department

Adaptation of Combustion Principles to Aircraft Propulsion, Volume 2, Combustion in Air-Breathing Jet Engines

Description: This volume continues the NACA study of combustion principles for aircraft propulsion. The various aspects of combustion pertinent to jet engines are organized and interpreted with quite extensive information, particularly for basic or fundamental. subject matter. The report concerns only air-breathing engines and hydrocarbon fuels, and not rocket engines and high-energy fuels. Since the references have been selected to illustrate important points, the bibliographies, while thorough, are not complete. This volumes describes the observed performance and design problems of engine combustors of the principal types. These include combustor-inlet conditions; starting, acceleration, combustion limits, combustion efficiency, coke deposits, and smoke formation in turbojets; ram-jet performance; and afterburner performance and design.
Date: May 2, 1956
Partner: UNT Libraries Government Documents Department

Additional comparisons between computed and measured transonic drag-rise coefficients at zero lift for wing-body-tail configurations

Description: From Introduction: "This report makes further comparisons of the theoretical computing method with available experimental results, showing effects of wing plan-form changes, and the effect of an airfoil-section change on a wing of given plan form."
Date: August 15, 1955
Creator: Holdaway, George H
Partner: UNT Libraries Government Documents Department

Additional fatigue tests on effects of design details in 355-T6 sand-cast aluminum alloy

Description: From Introduction: "Reported herein are results of the additional direct-stress fatigue tests on: (1) a plate-type specimen with cored centrally located hole and (2) 0.300-inch-diameter round polished specimens with various degrees of porosity."
Date: March 10, 1954
Creator: Eaton, I D & Youra, John A
Partner: UNT Libraries Government Documents Department

Additional measurements of the low-speed static stability of a configuration employing three triangular wing panels and a body of equal length

Description: From Introduction: "The results of an investigation of the low-speed static stability of a simplified model of such an arrangement having one of the airfoils placed vertically on top of the body and the other two as wing panels having negative dihedral are presented in reference 1. In order to provide information for predicting the effects of changes in the basic configuration on the low-speed stability characteristics presented in reference 1, additional measurements have been made."
Date: July 25, 1955
Creator: Delany, Noel K
Partner: UNT Libraries Government Documents Department

Additional results of an investigation at transonic speeds to determine the effects of a heated propulsive jet on the drag characteristics of a series of related afterbodies

Description: From Introduction: "Presented in this report are the basic data obtained from investigation. The data are presented with limited analysis in order to expedite their availability to those concerned with jet-exit-afterbody design."
Date: September 24, 1956
Creator: Henry, Beverly Z JR & Cahn, Maurice S
Partner: UNT Libraries Government Documents Department

Additional Results on the Static Longitudinal and Lateral Stability Characteristics of a 0.05-Scale Model of the Convair F2Y-1 Airplane at High Subsonic Speeds

Description: Additional results on the static longitudinal and lateral stability characteristics of a 0.05-scale model of the Convair F2Y-1 water-based fighter airplane were obtained in the Langley high-speed 7- by 10-foot tunnel over a Mach number range of 0.50 to 0.92. The maximum angle-of-attack range (obtained at the lower Mach numbers) was from -2 degrees to 25 degrees. The sideslip-angle range investigated was from -4 degrees to 12 degrees. The investigation included effects of various arrangements of wing fences, leading-edge chord-extensions, and leading-edge notches. Various fuselage fences, spoilers, and a dive brake also were investigated. From overall considerations of lift, drag, and pitching moments, it appears that there were two modifications somewhat superior to any of the others investigated: One was a configuration that employed a full-chord fence and a partial-chord fence located at 0.63 semispan and 0.55 semispan, respectively. The second was a leading-edge chord-extension that extended from 0.68 semispan to 0.85 semispan in combination with a leading-edge notch located at 0.68 semispan. With plus or minus 10 degrees aileron, the estimated wing-tip helix angle was reduced from 0.125 at a Mach number of 0.50 to 0.088 at a Mach number of 0.92, with corresponding rates of roll of 4.0 and 5.2 radians per second. The upper aft fuselage dive brake, when deflected 30 degrees and 60 degrees, reduced the rudder effectiveness about 10 to 20 percent and about 35 to 50 percent, respectively.
Date: August 10, 1954
Creator: Spreeman, Kenneth P. & Few, Albert G.
Partner: UNT Libraries Government Documents Department

Additional static and fatigue tests of high-strength aluminum-alloy bolted joints

Description: From Introduction: "Early in 1951 the National Advisory Committee for Aeronautics published, as Technical Note 2276 (ref. 1), a report by the Aluminum Research Laboratories of the Aluminum Company of America on the results of static and fatigue tests of high-strength aluminum alloy monobloc specimens and bolted joints. In view of special interest shown by several aircraft companies, certain expansions of the test program were undertaken by the Aluminum Research Laboratories and are reported herein."
Date: July 1954
Creator: Hartmann, E C; Holt, Marshall & Eaton, I D
Partner: UNT Libraries Government Documents Department

Adhesive and protective characteristics of ceramic coating A-417 and its effect on engine life of forged Refractaloy-26 (AMS 5760) and cast stellite 21 (AMS 5385) turbine blades

Description: The adhesive and protective characteristics of National Bureau of Standards Coating A-417 were investigated, as well as the effect of the coating on the life of forged Refractaloy 26 and cast Stellite 21 turbine blades. Coated and uncoated blades were run in a full-scale J33-9 engine and were subjected to simulated service operations consisting of consecutive 20-minute cycles (15 min at rated speed and approximately 5 min at idle). The ceramic coating adhered well to Refractaloy 26 and Stellite 21 turbine blades operated at 1500 degrees F. The coating also prevented corrosion of the Refractaloy 26, a corrosion-sensitive nickel-base alloy, and of the Stellite 21, a relatively corrosion-resistant cobalt-base alloy. Although the coating prevented corrosion of both alloys, it had no apparent effect on blade life.
Date: February 12, 1953
Creator: Garrett, Floyd B & Gyorgak, Charles A
Partner: UNT Libraries Government Documents Department

Advanced Designs of Magnetic Jack-Type Control Rod Drive

Description: Report containing information regarding magnetic jacks, which are devices used "for positioning the control rods in a nuclear reactor, especially in a reactor containing water under pressure" (page 9). Contains a description of the device, its use, test results, and illustrations.
Date: November 1959
Creator: Young, Joseph N.
Partner: UNT Libraries Government Documents Department

AEC Hot Cells and Related Facilities

Description: Foreward: The primary purpose of this report is to present as an accumulation of basic information on the hot cells constructed to date by the United States Atomic Energy Commission.
Date: May 1958
Creator: Fosdick, Ellery R.
Partner: UNT Libraries Government Documents Department

Aerodynamic and hydrodynamic characteristics of a deck-inlet multijet water-based-aircraft configuration designed for supersonic flight

Description: From Introduction: "In the present investigation, lift, drag, and pitching moment were determined over a Mach number range 0.6 to 1.42. Smooth-water takeoff and landing stability and resistance were investigated. A brief check of the rough-water spray and behavior was also made."
Date: December 5, 1956
Creator: Bielat, Ralph P; Coffee, Claude W , Jr & Petynia, William W
Partner: UNT Libraries Government Documents Department