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- Abstracts from the German Technical Press: Rates for Flights Organized by the State
- Report presenting tariffs that are written for all aircraft manufacturing companies to follow regarding aircraft orders.
- Abstracts Pertaining to Seaplanes
- Report discussing about 400 references pertaining to the hydrodynamic design of seaplanes have been compiled, and the information is presented in the form of abstracts classified under six main headings.
- Acceleration Characteristics of a Turbojet Engine With Variable-Position Inlet Guide Vanes
- 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.
- Acceleration Characteristics of R-3350 Engine Equipped with NACA Injection Impeller
- From Summary: "Qualitative investigations have shown that use of the NACA injection impeller with the R-3350 engine increases the inertia of the fuel-injection system and, when the standard fuel-metering system is used, this increase in inertia results in poor engine acceleration characteristics. This investigation was therefore undertaken to determine whether satisfactory acceleration characteristics of the engine equipped with the injection impeller could be obtained by simple modifications to the fuel-monitoring system. The engine was operated with two types of carburetor; namely, a hydraulic-metering carburetor incorporating a vacuum-operated accelerating pump and a direct-metering carburetor having a throttle-actuated accelerating pump."
- Acceleration Measurements During Landing in Rough Water of a 1/7-Scale Dynamic Model of Grumman XJR2F-1 Amphibian - Langley Tank Model 212: TED No. NACA 2378
- From Summary: "Tests of a 1/7 size model of the Grumman XJR2F-1 amphibian were made in Langley tank no.1 to examine the landing behavior in rough water and to measure the normal and angular accelerations experienced by the model during these landings. All landings were made normal to the direction of wave advance, a condition assumed to produce the greatest accelerations. Wave heights of 4.4 and 8.0 inches (2.5 and 4.7 ft, full size) were used in the tests and the wave lengths were varied between 10 and 50 feet (70 and 350 ft, full size)."
- Acceleration Measurements During Landings of a 1/5.5-Size Dynamic Model of the Columbia XJL-1 Amphibian in Smooth Water and in Waves: Langley Tank Model 208M, TED No. NACA 2336
- A 1/5.5-size powered dynamic model of the Columbia XJL-1 amphibian was landed in Langley tank no. 1 in smooth water and in oncoming waves of heights from 2.1 feet to 6.4 feet (full-size) and lengths from 50 feet to 264 feet (full-size). The motions and the vertical accelerations of the model were continuously recorded. The greatest vertical acceleration measured during the smooth-water landings was 3.1g.
- Acceleration of high-pressure-ratio single-spool turbojet engine as determined from component performance characteristics 1: effect of air bleed at compressor outlet
- 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."
- Acceleration of high-pressure-ratio single-spool turbojet engine as determined from component performance characteristics 2: effect of compressor interstage air bleed
- 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.
- Acceleration of high-pressure-ratio single-spool turbojet engine as determined from component performance characteristics 3: effect of turbine stator adjustment
- 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."
- An Acceleration Schedule Control for Accelerating a Turbojet Engine and Its Use With a Speed Control
- Memorandum presenting a study of an acceleration-limiting control on a turbojet engine in order to determine its feasibility as an acceleration control. A proportional-plus-integral type of controller was used in the investigation. Results regarding the one-loop control and two-loop control are provided.
- An Acceleration Schedule Control for Accelerating a Turbojet Engine and Its Use With a Speed Control
- Memorandum presenting an acceleration-limiting control used on a turbojet engine to study the feasibility of its use as an acceleration control. A proportional-plus-integral type of controller was used in this investigation. Results regarding one-loop control and two-loop control are provided.
- Acceleration, Stress, and Deflection Measurements on the XB-15 Bomber in Gusty Air
- From Introduction: "This report presents the results of these tests which cover a total of about 70 flying hours on this airplane."
- Accelerations and bottom pressures measured on a B-24D airplane in a ditching test
- From Introduction: "This report presents only that portion of the data from the first ditching which was to be used roughly establish the accelerations experienced by the pilot and the amount of water pressure to which the fuselage structure was subjected during the ditching."
- Accelerations and passenger harness loads measured in full-scale light-airplane crashes
- From Introduction: "Light-airplane accident data, compiled by Crash Injury Research of Cornell University Medical College, indicate that human beings have often withstood declarations in excess of those imposed in airplane crashes involving extensive damage to the airplane structure (ref. 1). This study also correlates the extent of damage to the airplane structure with the injury incurred by the occupants during crash accidents."
- Accelerations in fighter-airplane crashes
- From Introduction: "This report describes some measurements of these quantities obtained by crashing fighter aircraft under circumstances approximating those observed in service."
- Accelerations in Flight
- Report discussung work on accelerometry was done at McCook Field for the purpose of continuing the work done by other investigators and obtaining the accelerations which occur when a high-speed pursuit airplane is subjected to the more common maneuvers. The accelerations obtained in suddenly pulling out of a dive with well-balanced elevators are shown to be within 3 or 4 per cent of the theoretically possible accelerations. The maximum acceleration which a pilot can withstand depends upon the length of time the acceleration is continued. It is shown that he experiences no difficulty under the instantaneous accelerations as high as 7.8 G., but when under accelerations in excess of 4.5 G., continued for several seconds, he quickly loses his faculties.
- Accelerations in flight
- This report deals with the accelerations obtained in flight on various airplanes at Langley Field for the purpose of obtaining the magnitude of the load factors in flight and to procure information on the behavior of an airplane in various maneuvers. The instrument used in these tests was a recording accelerometer of a new type designed by the technical staff of the National Advisory Committee for Aeronautics. The instrument consists of a flat steel spring supported rigidly at one end so that the free end may be deflected by its own weight from its neutral position by any acceleration acting at right angles to the plane of the spring. This deflection is measured by a very light tilting mirror caused to rotate by the deflection of the spring, which reflected the beam of light onto a moving film. The motion of the spring is damped by a thin aluminum vane which rotates with the spring between the poles of an electric magnet. Records were taken on landings and takeoffs, in loops, spins, spirals, and rolls.
- Accelerations in Landing with a Tricycle-Type Landing Gear
- "In connection with the application of stable tricycle-type landing gears to transport airplanes, the question arises as to whether certain passengers may not experience relatively great accelerations in an emergency landing. Since the main landing wheels are behind the center of gravity in this type of gear, a hard-braked landing will cause immediate nosing down of the airplane and, when this motion is stopped due to the front wheel striking the ground, there will be some tendency for the rearmost passengers to be thrown out of their seats, The provided rough calculations are designed to show the magnitudes of the various reactions experienced in a severe landing under these circumstances" (p. 1).
- Accelerations in Transport-Airplane Crashes
- From Introduction: "A study of crash-impact survival in light airplanes is reported in references 1 and 2. A similar study for fighter airplanes is reported in reference 3. This report discusses crash-impact survival in transport airplanes."
- Accelerations Measured at Center of Gravity and Along Span of the Wing of a B-24D Airplane in Landing Impacts
- Report presenting measurements of a Consolidated B-24D airplane of accelerations at various points on the wing during landing impacts. landings were made with the wheels initially stationary but free to rotate, with the brakes set before contact, and with the main wheels rotating prior to contact.
- Accelerometer design
- In connection with the development of an accelerometer for measuring the loads on airplanes in free flight a study of the theory of such instruments has been made, and the results of this study are summarized in this report. A portion of the analysis deals particularly with the sources of error and with the limitations placed on the location of the instrument in the airplane. The discussion of the dynamics of the accelerometer includes a study of its theoretical motions and of the way in which they are affected by the natural period of vibration and by the damping, together with a report of some experiments on the effect of forced vibrations on the record.
- Accuracy of Airspeed Measurements and Flight Calibration Procedures
- From Summary: "The sources of error that may enter into the measurement of airspeed by pitot-static methods are reviewed in detail together with methods of flight calibration of airspeed installations. Special attention is given to the problem of accurate measurements of airspeed under conditions of high speed and maneuverability required of military airplanes." (author).
- Accuracy of Approximate Methods for Predicting Pressures on Pointed Nonlifting Bodies of Revolution in Supersonic Flow
- Note presenting an investigation of the accuracy and range of applicability of the linearized theory, second-order theory, tangent-cone method, conical-shock-expansion theory, and Newtonian theory for predicting pressure distributions on pointed bodies of revolution at zero angle of attack. Three shapes, cone, ogive, and a modified optimum body, are investigated over a wide range of fineness ratios and Mach numbers. The results indicated that for most combinations of fineness ratio and Mach number, one of the approximate methods will give reasonable results.
- The Accuracy of the Substitute-Stringer Approach for Determining the Bending Frequencies of Multistringer Box Beams
- "The accuracy of the substitute-stringer approach for including the effects of shear lag in the calculation of the transverse modes and frequencies of multistringer box beams is investigated. Box beams, the covers of which consist of normal-stress-carrying stringers on sheets which carry not only shear but also normal stress, are analyzed exactly. Frequencies of beams with various numbers of stringers, obtained by means of this exact analysis, serve to determine the possible accuracy of the frequencies obtained by the substitute-stringer approach" (p. 1).
- An accurate and rapid method for the design of supersonic nozzles
- From Introduction: "This report presents a computational procedure which provides for the rapid and accurate calculation of any streamline in a series of special flows. Detailed information is given on the boundary conditions and equations used for computing the characteristic nets and stream function."
- Accurate Calculation of Multispar Cantilever and Semicantilever Wings With Parallel Webs Under Direct and Indirect Loading
- In the present report the computation is actually carried through for the case of parallel spars of equal resistance in bending without direct loading, including plotting of the influence lines; for other cases the method of calculation is explained. The development of large size airplanes can be speeded up by accurate methods of calculation such as this.
- An Accurate Method of Measuring the Moments of Inertia of Airplanes
- From Summary: "This note contains a description of an improved apparatus and procedure used by the NACA for determining the moments of inertia of airplanes. The method used, based on the pendulum theory, is similar to that previously used, but a recent investigation of its accuracy has resulted in the improvements described herein. The error, when using the new apparatus and procedure, has been found to be of the order of 1 per cent."
- Achievement of Continuous Wall Curvature in Design of Two-Dimensional Symmetrical Supersonic Nozzles
- "Auxiliary boundary conditions are derived to assure continuity of wall curvature in applying the method of characteristics to the design of two-dimensional symmetrical supersonic nozzles. An illustrative example is included" (p. 1).
- Acoustic analysis of ram-jet buzz
- From Introduction: "The surging of a system containing a centrifugal- or axial-flow compressor (e.g., refs. 1 to 4) is an example of self-sustained oscillation. Inlets designed for supersonic jet engines also have been observed to induce oscillations (e.g., refs. 5 to 11) which are usually referred to as "buzz." The origin of buzz in ram-jet engines is the subject of the present report."
- Acoustic radiation from two-dimensional rectangular cutouts in aerodynamic surfaces
- 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."
- Acoustic, thrust, and drag characteristics of several full-scale noise suppressors for turbojet engines
- 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."
- Acoustical Treatment for the NACA 8- by 6-Foot Supersonic Propulsion Wind Tunnel
- "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" (p. 1).
- Acoustics of a Nonhomogeneous Moving Medium
- 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.
- Activation of hydrocarbons and the octane number
- This report presents an examination of the history of research on engine knocking and the various types of fuels used in the investigations of this phenomenon. According to this report, the spontaneous ignition of hydrocarbons doped with oxygen follows the logarithmic law within a certain temperature range, but not above 920 degrees K. Having extended the scope of investigations to prove hydrocarbons, the curves of the mixtures burned by air should then be established by progressive replacement of pure iso-octane with heptane. Pentane was also examined in this report.
- An active particle diffusion theory of flame quenching for laminar flames
- 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.
- Adaptation of a Cascade Impactor to Flight Measurement of Droplet Size in Clouds
- "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" (p. 1).
- Adaptation of aeronautical engines to high altitude flying
- Report discussing Issues and techniques relative to the adaptation of aircraft engines to high altitude flight. Covered here are the limits of engine output, modifications and characteristics of high altitude engines, the influence of air density on the proportions of fuel mixtures, methods of varying the proportions of fuel mixtures, the automatic prevention of fuel waste, and the design and application of air pressure regulators to high altitude flying. Summary: 1. Limits of engine output. 2. High altitude engines. 3. Influence of air density on proportions of mixture. 4. Methods of varying proportions of mixture. 5. Automatic prevention of fuel waste. 6. Design and application of air pressure regulators to high altitude flying.
- Adaptation of Combustion Principles to Aircraft Propulsion, Volume 1, Basic Considerations in the Combustion of Hydrocarbon Fuels with Air
- 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.
- Adaptation of Combustion Principles to Aircraft Propulsion Volume 2: Combustion in Air-Breathing Jet Engines
- 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.
- Adaptor for Measuring Principal Strains With Tuckerman Strain Gage
- Report discussing an adapter which uses three Tuckerman optical strain gages to measure the displacement of the three vortices of an equilateral triangle along lines 120 degrees apart. These displacements are substituted in well-known equations in order to compute the magnitude and direction of the principal strains. Tests of the adaptor indicate that principal strains over a gage length of 1.42 inch may be measured with a systematic error not exceeding 4 percent and a mean observational error of the order of + or minus 0.000006. The maximum observed error in strain was of the order of 0.00006. The directions of principal strains for unidirectional stress were measured with the adaptor with an average error of the order of 1 degree.
- Addition of Heat to a Compressible Fluid in Motion
- From Introduction: "The purpose of this report is to summarize, without extended proofs, the results of a study of a simplified model of nonadiabiatic, compressible fluid flow, both subsonic and supersonic, and to state these results in a form that will make them immediately useful in providing a theoretical background for current technical problems of high-speed combustion.
- Additional Abstracts Pertaining to Seaplanes
- "About 500 additional references pertaining to hydrodynamic design of seaplanes have been compiled, and the information is presented in the form of abstracts classified under six main headings:GENERAL INFORMATION, HYDROSTATICS, HYDRODYNAMICS, AERODYNAMICS, OPERATION, and RESEARCH. The compilation is an extension of NACA RM No. L6I13, entitled "Abstracts Pertaining to Seaplanes," by Jerold M. Bidwell and Douglas A. King. An author index and a subject index are included" (p. 1).
- Additional comparisons between computed and measured transonic drag-rise coefficients at zero lift for wing-body-tail configurations
- 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."
- Additional design charts relating to the stalling of tapered wings
- From Introduction: "The present report, therefore, may be considered a supplement to reference 1. The combined scope of the stall charts of reference 1, designated A, and of the present work, designated B, is summarized in the following table: For the wing with root thickness ratio to 18 was also investigated.
- Additional experimental heat-transfer and durability data on several forced-convection, air-cooled, strut-supported turbine blades of improved design
- 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.
- Additional Experiments With Flat-Top Wing- Body Combinations at High Supersonic Speeds
- Memorandum presenting an experimental study of the effects of several variations in configuration geometry on the aerodynamic characteristics of flat-top wing-body combinations. Generally, the configurations consist of one half of a body of revolution mounted beneath a wing of essentially arrow plan form. Results regarding the effect of trailing-edge sweep, effect of the addition of auxiliary bodies, effect of tip-flap deflection, effect of dihedral, effect of leading-edge sweep, effect of fuselage fineness ratio, effect of fuselage profile shape, and static longitudinal stability characteristics are provided.
- Additional Fatigue Tests on Effects of Design Details in 355-T6 Sand-Cast Aluminum Alloy
- 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."
- Additional free-flight tests of the rolling effectiveness of several wing-spoiler arrangements at high subsonic, transonic, and supersonic speeds
- From Introduction: "The purpose of the present paper is to present results obtained recently relating to the characteristics of a full-span sharp-edge spoiler with an 0.02-chord projection above the wing surface at several chordwise positions and also to the relative effectiveness of the sharp-edge spoiler and a wedge-type spoiler located at the 80-percent-chord line."
- An Additional Investigation of the High-Speed Lateral-Control Characteristics of Spoilers
- Report presenting an investigation of the characteristics of partial-span spoilers located at 0.75 of the chord on an NACA 66-series tapered wing, especially at high speeds. The effect of small spoiler projections was found to increase with an increase in speed until the critical Mach number was exceeded.
- The additional-mass effect of plates as determined by experiments
- From Introduction: "The apparent increase in the inertia properties of a body moving in a fluid medium has been called the additional-mass effect. This report presents a resume of test procedures and results of experimental determinations of the additional-mass effect of flat plates. In addition to data obtained from various foreign sources and from a NACA investigation in 1933, the results of tests recently conducted by the National Advisory Committee for Aeronautics are included."