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Ability of pilots to control simulated short-period yawing oscillations

Description: Report discussing an investigation into the ability of human pilots to control short-period yawing oscillations using a yaw simulating device. The ability to control the oscillations was determined to be a function of period, control effectiveness, and inherent damping. Pilot control effectiveness was found to improve with practice.
Date: November 13, 1950
Creator: Phillips, William H. & Cheatham, Donald C.

Acceleration characteristics of a turbojet engine with variable-position inlet guide vanes

Description: Report presenting a study of the acceleration characteristics of a turbojet engine equipped with variable-position inlet guide vanes in the altitude test chamber. Maximum acceleration values for 3 engines of the same model were also obtained during testing and were found to differ as much as 50 percent. Results regarding the effect of fuel step size and inlet guide vane on acceleration, effect of flight condition, reproducibility of engine acceleration, compressor pressure ratio in relation to acceleration, and acceleration with inlet air distortion are provided.
Date: July 7, 1955
Creator: Dobson, W. F. & Wallner, Lewis E.

Acceleration of high-pressure-ratio single-spool turbojet engine as determined from component performance characteristics 1: effect of air bleed at compressor outlet

Description: From Summary: "An analytical investigation was made to determine from component performance characteristics the effect of air bleed at the compressor outlet on the acceleration characteristics of a typical high-pressure-ratio single-spool turbojet engine. Consideration of several operating lines on the compressor performance map with two turbine-inlet temperatures showed that for a minimum acceleration time the turbine-inlet temperature should be the maximum allowable, and the operating line on the compressor map should be as close to the surge region as possible throughout the speed range. Operation along such a line would require a continuously varying bleed area."
Date: March 10, 1953
Creator: Rebeske, John J., Jr. & Rohlik, Harold E.

Acceleration of high-pressure-ratio single-spool turbojet engine as determined from component performance characteristics 2: effect of compressor interstage air bleed

Description: Report presenting an analytical investigation to determine the effect of compressor interstage air bleed with the use of constant-area bleed ports on the acceleration characteristics of a typical high-pressure-ratio single-spool turbojet engine. Constant-area interstage bleed, properly located, gave smaller acceleration times than variable-area compressor exit bleed. Results regarding acceleration with interstage bleed, acceleration using constant-area interstage bleed in combination with compressor outlet bleed, variable-area interstage bleed, and comparison of acceleration modes are provided.
Date: July 3, 1953
Creator: Rebeske, John J., Jr. & Dugan, James F., Jr.

Acceleration of high-pressure-ratio single-spool turbojet engine as determined from component performance characteristics 3: effect of turbine stator adjustment

Description: From Summary: "An analytical investigation was made to determine from component performance the effect of turbine stator adjustment on the acceleration characteristics of a typical high-pressure-ratio single-spool turbojet engine. Turbine stator adjustment was adequate to permit engine operation in the intermediate-speed range, but was less satisfactory than the relatively simple schemes of compressor-interstage and -outlet bleed."
Date: August 2, 1954
Creator: Rohlik, Harold E. & Rebeske, John J.

Accelerations in fighter-airplane crashes

Description: From Introduction: "This report describes some measurements of these quantities obtained by crashing fighter aircraft under circumstances approximating those observed in service."
Date: November 4, 1957
Creator: Acker, Loren W.; Black, Dugald O. & Moser, Jacob C.

An active particle diffusion theory of flame quenching for laminar flames

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.

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

Description: From Summary: "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."
Date: September 18, 1951
Creator: Levine, Joseph & Kleinknecht, Kenneth S.

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.

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

Additional experimental heat-transfer and durability data on several forced-convection, air-cooled, strut-supported turbine blades of improved design

Description: Report presenting an investigation at the Lewis laboratory to develop air-cooled, strut-supported turbine blades. Six blades were investigated in a full-scale turbojet engine to obtain data on blade durability and blade-cooling effectiveness and strut temperature. Results regarding the heat-transfer investigation and blade-durability investigation are provided.
Date: January 19, 1955
Creator: Schum, Eugene F.

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.

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.

Additional studies of the stability and controllability of an unswept-wing vertically rising airplane model in hovering flight including studies of various tethered landing techniques

Description: Report discussing the results of an investigation to determine the stability and control characteristics of a flying model of an unswept-wing vertically rising airplane. Information about stabilization, maneuverability, rolling motions, and landings is provided.
Date: November 6, 1951
Creator: Bates, William R.; Lovell, Powell M., Jr. & Smith, Charles C., Jr.

The adhesion of molten boron oxide to various materials

Description: This report includes the description and results of an experiment evaluating the amount of adhesion existing between the liquid boron oxide and various materials used in engines.
Date: April 1, 1958
Creator: Witzke, W. R.

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.

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.