National Advisory Committee for Aeronautics (NACA) - 620 Matching Results

Search Results

Results: 1 - 50 next
Abnormal Grain Growth in S-816 Alloy
From Introduction: "This report presents the results obtained to date of an investigation to establish the fundamental causes of abnormal growth in S-816 alloy under conditions encountered during the forging of blades for the gas turbine of jet engines."
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).
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."
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.
The adhesion of molten boron oxide to various materials
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.
Aerodynamic characteristics at Reynolds numbers of 3.0 x 10(exp 6) and 6.0 x 10(exp 6) of three airfoil sections formed by cutting off various amounts from the rear portion of the NACA 0012 airfoil section
Report presenting an investigation of the two-dimensional aerodynamic characteristics of three airfoil sections formed by removing various portions of the original chord from the trailing edge of the NACA 0012 airfoil section. Results regarding lift, drag, and pitching moment and aerodynamic center are provided.
The aerodynamic characteristics at transonic speeds of a model with a 45 degree sweptback wing, including the effect of leading edge slats and a low horizontal tail
Report presenting an investigation in the 16-foot transonic tunnel to determine the effects of leading-edge slats on the aerodynamic and longitudinal stability characteristics of a model of a swept-wing fighter-type airplane. Two different spanwise extents of leading-edge slats were tested, from 35 to 95 percent semispan and from 46 to 95 percent semispan. Results regarding the lift characteristics, drag characteristics and lift-drag ratios, stability characteristics, and flow-study pictures are provided.
Aerodynamic Characteristics of a 0.04956-Scale Model of the Convair F-102A Airplane at Transonic Speeds
"Tests have been conducted in the Langley 8-foot transonic tunnel on a 0.04956-scale model of the Convair F-102A airplane which employed an indented and extended fuselage, cambered wing leading edges, and deflected wing tips. Force and moment characteristics were obtained for Mach numbers from 0.60 to 1.135 at angles of attack up to 20 degrees. In addition, tests were made over a limited angle-of-attack range to determine the effects of the cambered leading edges, deflected tips, and a nose section with a smooth area distribution" (p. 1).
Aerodynamic characteristics of a 60 degree delta wing having a half-delta tip control at a Mach number of 4.04
From Introduction: "Numerous tests of tip controls on delta wings at transonic and low supersonic speeds have shown that such configurations provide satisfactory rolling-moment effectiveness, and that the hinge can be controlled by proper location of the hinge line (ref. 1). The purpose of the present tests is to determine the characteristics of such a configuration at Mach number of 4.04 and a Reynolds number of 5.8 X 10^6, based on the wing mean aerodynamic chord."
Aerodynamic characteristics of a cruciform-wing missile with canard control surfaces and of some very small span wing-body missiles at a Mach number of 1.41
Report presenting an investigation to determine the aerodynamic characteristics of a cruciform 70 degree delta-wing missile configuration with 70 degree delta canard control surfaces at M = 1.41 in the 4- by 4-foot supersonic pressure tunnel. Modifications to the configuration included variation of the body length and canard area and the substitution of a series of very small span wings for the cruciform delta wings and canard controls.
The aerodynamic characteristics of a supersonic aircraft configuration with a 40 degree sweptback wing through a Mach number range from 0 to 2.4 obtained from various sources
"A summary and analysis have been made of the results of various investigations to determine the aerodynamic characteristics of a supersonic aircraft configuration. The configuration has a wing with 40 degree sweepback at the quarter-chord line, aspect ratio 4, taper ratio 0.5, and 10-percent-thick circular-arc sections normal to the quarter-chord line. Experimental data were available for a Mach number range from 0.16 to 2.32. Results obtained from wing-flow, rocket-model, transonic-bump, and tunnel tests are presented and, where possible, are supplemented by empirical and theoretical calculations" (p. 1).
Aerodynamic characteristics of two flat-bottomed bodies at Mach number of 3.12
From Introduction: "This report presents the results of an investigation in the NACA Lewis 1- by 1-foot supersonic wind tunnel of two flat-bottomed bodies to determine their aerodynamic characteristics at a Mach number of 3.12."
The aerodynamic design and calibration of an asymmetric variable Mach number nozzle with a sliding block for the Mach number range 1.27 to 2.75
From Introduction: "This paper presents the basic design method and experimental results of calibration of a nozzle which was constructed to conform to the analytically determined ordinates."
Aerodynamic Loads on an External Store Adjacent to a 60 Degree Delta Wing at Mach Numbers From 0.75 to 1.96
Report presenting an investigation to determine separately the aerodynamic characteristics of a Douglas Aircraft Company store and a semispan delta-wing-fuselage configuration in the presence of one another. The store was located at the 50-percent-semispan station with the store nose both ahead of and behind the wing leading edge for two longitudinal and three vertical positions.
Aerodynamics of slender bodies at Mach number of 3.12 and Reynolds numbers from 2 x 10(exp 6) to 15 x 10(exp 6) 3: boundary layer and force measurements on a slender cone-cylinder body of revolution
Report presenting an experimental investigation to determine the aerodynamic characteristics of a slender cone-cylinder body of revolution in the 1- by 1-foot supersonic wind tunnel. Viscous drag and three component forces were measured at Mach number 3.12 and a range of Reynolds numbers and angles of attack. Results regarding pressure distributions, boundary layer, and forces are provided.
Aeronautical interference effects on normal and axial force coefficients of several engine-strut-body configurations at Mach numbers of 1.8 and 2.0
Report presenting an investigation of the aerodynamic interference effects associated with a missile configuration, consisting of a pointed body of revolution with one or two ramjet engines strut-mounted in a vertical plane through the center line of the body, at several engine locations relative to the body and a range of angles of attack. The experimental data indicated increases in slope of the normal force curve with outward movement of the engines. Results regarding the characteristics of isolated components, characteristics of representative configurations, interference effects, and effect of engine location on lift-drag ratio are provided.
Altitude Operation of Gas-Turbine Engine With Variable-Area Fuel-Nozzle System
From Introduction: "The investigation reported herein was therefore undertaken to extend this study to altitude conditions in which the low fuel-flow rates occur over the full range of engine speeds."
Altitude performance and operational characteristics of 29-inch-diameter tail-pipe burner with several fuel systems and fuel-cooled stage-type flame holders on J35-A-5 turbojet engine
An investigation of tail-pipe burning was conducted in the NACA Lewis altitude wind tunnel with a full-scale turbojet engine and an 29-inch-diameter tail-pipe burner. Effects of fuel distribution and number and arrangement of stages on performance and operational characteristics of several fuel-cooled flame holders are presented and discussed. Operation with a three-stage flame holder having the large stage upstream was the most efficient. Combustion efficiency was slightly increased at high altitudes by injecting fuel upstream of the flame holder.
Altitude performance of pentaborane - JP-4 fuel blends in a modified J47 combustor
From Introduction: "Experimental investigations of the combustion characteristics of diborane, pentaborane, and pentaborane-hydrocarbon blends in modified turbojet combustors have been conducted at this laboratory at the request of the Bureau of Aeronautics, Department of the Navy, as part of Project Zip. Results of these single-combustor tests are presented in references 2 to 5."
Altitude Starting Characteristics of an Afterburner With Autoignition and Hot-Streak Ignition
"Ignition of the fuel-air mixture in an afterburner of turbojet engine at altitude has often proved to be a different problem to solve. Electrical ignition has not proven satisfactory because of the unreliability of such systems (ref. 1). The ignition data reported herein were obtained for two after-burner configurations. Autoignition data are included for both configurations and hot-streak-ignition data, for only one. "
The Ames supersonic free-flight wind tunnel
From Introduction: "Because of the unusual nature of this equipment, and because it is proving to be very useful for certain kinds of aerodynamic research, this report has been prepared. It contains a description of the equipment and its use to obtain aerodynamic coefficients. The imperfections in the wind-tunnel air stream and their effect on model tests are also discussed."
The Ames Supersonic Free-Flight Wind Tunnel
Memorandum presenting a description of the Ames supersonic free-flight wind tunnel, which is a new piece of equipment for aerodynamic research at high supersonic Mach numbers. It has a wide Mach number range extending from low supersonic speeds to Mach numbers in excess of 10. The air stream in the tunnel is imperfect, mainly due to a symmetrical pair of oblique shock waves which reflect down the test section.
Amplitude distribution and energy balance of small disturbances in plate flow
From Introduction: "The present report, therefore, deals first, with the distribution of the amplitude of the disturbance over the flow section, that is, the calculation of the characteristic functions and second, with the study of the energy distribution and energy balance of the disturbance motion. The investigations are based upon the disturbances of the laminar flow past a flat plate which are situated exactly at the boundary between amplification and damping (neutral oscillations)."
An analog study of the relative importance of various factors affecting roll coupling
From Introduction: "In this study wide variations in many of the pertinent aerodynamic were investigated at subsonic and supersonic speeds. The effects of large changes in principal axis inclination and mass distribution are also included. The primary purpose of this paper is to summarize the information obtained from the analog calculations and to compare the results with the trends predicted from a slightly modified version of reference 2."
Analysis and Calculation by Integral Methods of Laminar Compressible Boundary-Layer With Heat Transfer and With and Without Pressure Gradient
From Introduction: "The purpose of the present report is to present a comprehensive summary of theoretical investigations of comprehensible laminar boundary layers which have been carried out since 1949 at the Polytechnic Institute of Brooklyn under the sponsorship and with the financial assistance of the National Advisory Committee for Aeronautics. The results of these investigations are contained primarily in references 1 to 7."
Analysis and comparison with theory of flow-field measurements near a lifting rotor in the Langley full-scale tunnel
From Introduction: "The time-averaged flows are considerably simpler to deal with theoretically than are the instantaneous flows, and the results of several theoretical analyses are available (refs. 2 to 6, for example). Several previous experimental investigations (see ref. 7 for a bibliography) have provided some qualitative information on the subject by the use of smoke in flight and in wind tunnels. However, quantitative measurements (refs. 8 to 10) are extremely scarce and, in general, are inadequate either to define the nature of the flow or to check the accuracy of the theoretical calculations."
Analysis of a spin and recovery from time histories of attitudes and velocities as determined for a dynamic model of a contemporary fighter airplane in the free-spinning tunnel
From Introduction: "In this paper are presented descriptions of the camera setups and associated equipment, the equations and methods used in determining the model attitudes and motions from the film, and time-history curves of the variables of the spin and recovery investigated. Discussions of the nature of the spin and recovery obtained and of factors ostensibly affecting these motions are included."
An Analysis of Air-turborocket Engine Performance Including Effects of Component Changes
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.
Analysis of an automatic control to prevent rolling divergence
From Introduction: "The use of automatic controls to reduce the tendency for rolling divergence has been investigated in references 2 and 3. These studies have considered the effect of artificial changes in certain stability derivatives on the rolling divergence, and have shown that increased damping in pitch may be quite effective in reducing the divergent tendency. In the present report, a different type of automatic control is investigated."
Analysis of an induction blowdown supersonic tunnel
From Introduction: "In the present paper, general ejector equations (see reference 4 or 5) and certain assumptions with regard to flow conditions and pressure losses have been utilized to calculate the running times of induction blowdown supersonic tunnels operating in the mentioned Mach number range."
Analysis of cooling-air requirements of corrugated-insert-type turbine blades suitable for a supersonic turbojet engine
From Introduction: "This report presents the cooling-air requirements of a "paper" air-cooled turbojet engine operating over a wide range of flight Mach numbers and altitudes. The results are presented for a two-stage-turbine turbo-jet engine having a turbine-inlet temperature of 2500^o R and operating at sea-level static conditions and flight Mach numbers from 0.90 to 2.5 and flight altitudes from 40,000 to 70,000 feet. In addition, the effect of decreasing the blade-inlet cooling-air temperature on the required coolant-flow ratio is presented."
An analysis of estimated and experimental transonic downwash characteristics as affected by plan form and thickness for wing and wing-fuselage configurations
From Introduction: "The purpose of the present paper is to present summary of the information gleaned from various transonic-bump investigations of wing and wing-fuselage configurations at two representative tail heights and to compare these results with theoretical estimations made in subsonic and supersonic Mach number range."
Analysis of Flight-Determined and Predicted Effects of Flexibility on the Steady-State Wing Loads of the B-52 Airplane
Memorandum presenting an investigation of the steady-state wing loads conducted on a Boeing B-52 airplane over a range of Mach numbers and altitudes. Results regarding flight tests and air-load calculations are provided.
Analysis of flight-determined and predicted effects of flexibility on the steady-state wing loads of the B-52 airplane
From Introduction: "This paper presents the results obtained during the phase of the B-52 flight investigation concerned with the steady-state wing loads. Where possible, the effects of Mach number and flexibility on the measured load are analyzed and presented."
Analysis of harmonic forces produced at hub by imbalances in helicopter rotor blades
From Introduction: "First, an analysis of loads transmitted to the hub by balanced blades will be given. In the second section, the additional loads transmitted to the hub in a direction normal to the plane of rotation of the blades by imbalances in a rotor are derived. In the entire analysis, the results are given in terms of the forces transmitted to the hub by a single rotating helicopter blade in flight, and these are regarded as known or given."
Analysis of heat addition in a convergent-divergent nozzle
From Introduction: "The purpose of this report is to treat analytically heat addition heat addition to a divergent stream with initially sonic flow and to employ the results thus obtained in evaluating the effect of delayed combustion on convergent-divergent nozzle performance."
Analysis of Heat Transfer and Fluid Friction for Fully Developed Turbulent Flow of Supercritical Water With Variable Fluid Properties in a Smooth Tube
From Summary: "Calculated velocity and temperature distributions, as well as relations among Nusselt number, Reynolds number, and friction factor, are presented. The effect of variation of fluid properties across the tube on the Nusselt number and friction factor correlations can be eliminated by evaluating the properties at a reference temperature which is a function of both the wall temperature and the ratio of wall-to-bulk temperatures."
An Analysis of Pressure Studies and Experimental and Theoretical Downwash and Sidewash Behind Five Pointed-Tip Wings at Supersonic Speeds
The following report covers an investigation that was done to supplement available experimental data on flow fields behind wings of an aircraft at supersonic speeds, as well as to furnish more quantitative information on the choice of the theoretical method for a given configuration and the accuracy to be expected when using such a method.
Analysis of Static Aeroelastic Behavior of Low-Aspect-Ratio Rectangular Wings
"Slender-body theory is used in conjunction with late theory to analyze the static aeroelastic-divergence behavior of low-aspect-ratio rectangular wings of constant thickness when chordwise deformations are considered. In the analysis, the spanwise variation of the deflection is restricted to a parabola but the chordwise variation is allowed complete freedom. Results show the variation of the divergence speed and mode shape with the aspect ratio" (p. 1).
An analysis of surface pressures and aerodynamic load distribution over the swept wing of the Douglas D-558-II research airplane at Mach numbers from 0.73 to 1.73
Report presenting the wing-section pressure-distribution and wing-panel load characteristics of the Douglas D-558-II airplane for a range of Mach numbers and airplane normal-force coefficients. At subsonic speeds, the pressure distributions are characterized by a high negative-pressure peak with an abrupt pressure recovery as a result of the leading-edge expansion over the upper surface at moderate angles of attack.
Analysis of the turbojet for propulsion of supersonic bombers
From Introduction: "The investigation is discussed in the present report is an analysis of the turbojet engine as the power plant for bombers capable of supersonic flight speeds. A similar analysis, in which the turbojet engine is considered for the propulsion of supersonic fighter aircraft, is presented in reference 1. Two plans are considered in this report."
Analysis of Turbulent Flow and Heat Transfer on a Flat Plate at High Mach Numbers With Variable Fluid Properties
From Introduction: "In the turbulent case, however, the results of the various analyses disagree markedly because of the different assumptions made by various authors. These analyses are reviewed in references 1 to 3. The analysis is extended to flow and heat transfer in a boundary layer at high Mach numbers in this paper. (Some preliminary results were presented in ref. 11.)"
Analytic determination of the discharge coefficients of flow nozzles
From Introduction: "In rounded-approach nozzles with discharge coefficients close to unity, the frictional effects are concentrated in the boundary layer. A method of obtaining an analytical relation among the discharge coefficient, Reynolds number, and the nozzle geometry by utilization of elementary boundary-layer theory is presented herein."
Analytical and experimental investigation of thrust augmentation of axial- and centrifugal-compressor turbojet engines by injection of water and alcohol in combustion chambers
Report presenting an investigation of thrust augmentation by injection of water and water-alcohol mixtures in the combustion chambers at sea-level zero-ram flight conditions on 4000-pound-thrust axial-flow and centrifugal-flow turbojet engines. Thrust augmentation, compressor characteristics, fuel flow, and turbine-outlet-temperature distributions are presented for various injection rates and water-alcohol mixtures.
Analytical determination of local surface heat-transfer coefficients for cooled turbine blades from measured metal temperatures
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."
An Analytical Evaluation of the Effects of an Aerodynamic Modification and of Stability Augmenters on the Pitch Behavior and Probable Pilot Opinion of Two Current Fighter Airplanes
Memorandum presenting the effects of wing modification and stability augmentation on the computed longitudinal behavior in the pitch-up region and probable pilot opinion of the pitch-up characteristics of two current fighter airplanes. An exploration of the addition of a wing-leading edge is included. Results regarding computed pitch-up behavior and probable pilot opinion are provided.
Analytical investigation of factors affecting the performance of single-stage turbines having rotor-tip discharge of cooling air
From Introduction: "The purpose of this report is to further analyze the turbine performance results of reference 1 with the objective of isolating the contribution of the cooling air to the turbine performance and establishing some systematic relation between these cooling-air effects and the turbine operational parameters."
Analytical Studies of the Response to Longitudinal Control of Three Airplane Configurations in Landing Approaches
Memorandum presenting a theoretical investigation to determine the reasons for poor airplane response to longitudinal control. Some effects of airplane configuration on the response, primarily for short time periods, were also determined. Results regarding a comparison of three airplanes, the effect of changes on airplane B, and the effect of changes on airplane C are provided.
Analytical studies of the response to longitudinal control of three airplane configurations in landing approaches
From Introduction: "A theoretical investigation was conducted in order to determine what effect the differences in aerodynamic characteristics would have on the short-time response to elevator control of this type of airplane as compared with the responses of a conventional airplane, without regard to any possible psychological influences. The results of this investigation are presented in this paper."
Apparatus for Measurements of Time and Space Correlation
The report describes a brief review is made of improvements to an experimental apparatus for time and space correlation designed for study of turbulence. Included is a description of the control of the measurements and a few particular applications.
Back to Top of Screen