Search Results

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.
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."
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
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.
Aerodynamic characteristics at high and low subsonic Mach numbers of four NACA 6-series airfoil sections at angles of attack from -2 to 31 degrees
From Introduction: "The airfoil sections tested, which differ only in thickness ratio, were the NACA 64-006, 64-008, 64-010, and 641-012. Lift, drag, and pitching-moment data were obtained for Mach numbers of 0.3 to that for tunnel choke at angles of attack of -2^o to 31^o. The results of this investigation are reported herein."
Aerodynamic characteristics at Mach number 4.04 of a rectangular wing of aspect ratio 1.33 having a 6-percent-thick circular-arc profile and a 30-percent-chord full-span trailing-edge flap
From Introduction: "The present report gives results at a Mach number of 4.04 of the part of the program concerned with flap controls at Mach numbers from 1.62 to 6.9."
The Aerodynamic Characteristics at Transonic Speeds of an All-Movable, Tapered, 45 Degree Sweptback, Aspect-Ratio-4 Tail Deflected About a Skewed Hinge Axis and Equipped with an Inset Unbalancing Tab
From Introduction: "The present investigation presents the lift and moment characteristics of an aspect-ratio-4.0 tail, sweptback 45^o at the quarter-chord line and pivoted about an axis sweptback 55.5^o and passing through the leading edge of the root-chord line."
Aerodynamic Characteristics in Pitch and Sideslip at High Subsonic Speeds of a 1/14-Scale Model of the Grumman XF104 Airplane with Wing Sweepback of 42.5 Degrees
"An investigation has been made at high subsonic speeds of the aerodynamic characteristics in pitch and sideslip of a 1/l4-scale model of the Grumman XF10F airplane with a wing sweepback angle of 42.5. The longitudinal stability characteristics (with the horizontal tail fixed) indicate a pitch-up near the stall; however, this was somewhat alleviated by the addition of fins to the side of the fuselage below the horizontal tail. The original model configuration became directionally unstable for small sideslip angles at Mach numbers above 0.8; however, the instability was eliminated by several different modifications" (p. 1).
Aerodynamic characteristics in pitch of a series of cruciform-wing missiles with canard controls at a Mach number of 2.01
From Introduction: "This paper presents the results of tests made at a Mach number of 2.01 to determine the effect of body length on the longitudinal characteristics (zero roll angle) for five complete configurations as well as for the bodies alone, the bodies plus wings, and the bodies plus canard surfaces. The experimental results are compared with some simple theoretical estimates."
Aerodynamic characteristics of a 68.4 degree delta wing at Mach numbers of 1.6 and 1.9 over a wide Reynolds number range
From Introduction: "The purpose of this paper is to provide further information on the effects of Reynolds number on the aerodynamic characteristics of the wing of reference 1 as well as to provide load distributions for the wing at Mach numbers of 1.6 and 1.9."
Aerodynamic Characteristics of a Refined Deep-Step Planing-Tail Flying-Boat Hull with Various Forebody and Afterbody Shapes
From Summary: "An investigation was made in the Langley 300 mph 7-by 10-foot tunnel to determine the aerodynamic characteristics of a refined deep-step planing-tail hull with various forebody and afterbody shapes. For comparison, tests were made on a streamline body simulating the fuselage of a modern transport airplane. The results of the tests, which include the interference effects of a 21-percent-thick support wing, indicated that for corresponding configurations the hull models incorporating a forebody with a length-beam ratio of 7 had lower minimum drag coefficients than the hull models incorporating a forebody with a length-beam ratio of 5. Longitudinal and lateral stability was generally about the same for all hull models tested and about the same as that of a conventional hull."
Aerodynamic characteristics of a two-blade NACA 10-(3)(062)-045 propeller and of a two-blade NACA 10-(3)(08)-045 propeller
Report discussing characteristics are given for the two-blade NACA 10-(3)(062)-045 propeller and for the two-blade NACA 10-(3)(08)-045 propeller over a range of advance ratio from 0.5 to 3.8, through a blade-angle range from 20 degrees to 55 degrees measured at the 0.75 radius. Maximum efficiencies of the order of 91.5 to 92 percent were obtained for the propellers. The propeller with the thinner airfoil sections over the outboard portion of the blades, the NACA 10-(3)(062)-045 propeller, had lower losses at high tip speeds, the difference amounting to about 5 percent at a helical tip Mach number of 1.10.
The aerodynamic characteristics of an aspect-ratio-20 wing having thick airfoil sections and employing boundary-layer control by suction
Report presenting an investigation to study the aerodynamic characteristics of an aspect-ratio-20 wing with thick airfoil sections and employing boundary-layer control by suction. The results include the effects of varying suction flow rate, suction-slot configuration, wing surface condition, flap deflection, and Mach number are provided.
Aerodynamic Characteristics of Low-aspect-ratio Wings at High Supersonic Mach Numbers
Memorandum presenting some recently obtained data on the aerodynamic characteristics of low-aspect-ratio wings at supersonic Mach number of 4.04 and 6.9 and discusses some new methods of predicting the lift and drag of such wings. The plan forms, airfoil sections, and thickness ratios of the wings tested are provided.
Aerodynamic characteristics of low-aspect-ratio wings at high supersonic Mach numbers
From Introduction: "This paper presents some recently obtained data on the aerodynamic characteristics of low-aspect-ratio wings at supersonic Mach numbers of 4.04 and 6.9 and discusses some new methods of predicting the lift and drag of such wings. Data on lifting wings in the Mach number range above 2.5 are not plentiful and most of the available data may be found in NACA RM L51D17, NACA RM L51D30, NACA RM L52D15a, NACA RM L52K19, NACA RM L53D03, and NACA RM L53D30a."
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 forces and loadings on symmetrical circular-arc airfoils with plain leading-edge and plain trailing-edge flaps
From Summary: "An investigation has been made in the Langley two-dimensional low-turbulence tunnel and in the Langley two-dimensional low-pressure tunnel of 6- and 10-percent-thick symmetrical circular-arc airfoil sections at low Mach numbers and several Reynolds numbers. The airfoils were equipped with 0.15-chord plain leading-edge flaps and 0.20-chord plan trailing-edge flaps. The section lift and pitching-moment characteristics were determined for both airfoils with the flaps deflected individually and in combination."
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.
Aileron and Elevator Hinge Moments of the Bell X-1 Airplane Measured in Transonic Flight
"During the flight investigation of the X-1 airplane the hinge moments of the elevator and aileron control surfaces have been measured over a Mach number range extending to above 1.0. The results of these measurements are presented in this paper" (p. 2).
Air Admixture to Exhaust Jets
From Introduction: "The problem of thrust increase for jet engines by air mixture to the exhaust jet was introduced into aviation techniques by the suggestions of Melot (ref.1). Due to a too general interpretation of several theoretical investigations of A. Busemann (ref.2), so far no practical use has been made of these suggestions. The following considerations show that, in the case of low-pressure mixing according to Melot's suggestions, probably no thrust increase of technical significance will occur for the flight speeds of interest (however, the low-pressure mixture is highly promising for ground test setups and for special power plants of relatively slow sea and land vehicles."
Air-flow and thrust characteristics of several cylindrical cooling-air ejectors with a primary to secondary temperature ratio of 1.0
Report presenting an investigation to determine the performance of 17 cooling-air ejectors at primary-jet pressure ratios from 1 to 10, secondary pressure ratios to 4.0, and a temperature ratio of unity. Results regarding pumping characteristics, effect of spacing ratio on pumping, effect of diameter ratio on pumping, thrust characteristics, effect of spacing ratio on thrust, effect of diameter ratio on thrust, comparison of cylindrical and conical ejectors, comparison of performance with small model ejectors, and a comparison of performance with full-scale installation are provided.
Air-flow characteristics of brazed and rolled wire filter cloth for transpiration-cooled afterburners
From Introduction: "Because of variation in the static-pressure drop across the porous material and in the cooling air required along the length of afterburner combustion chambers, a prescribed distribution of permeability is usually necessary. However, as a preliminary investigation, this report is concerned only with the attainment of uniform permeability. The results of an experimental investigation, conducted at the NACA Lewis laboratory, to determine the permeabilities of five thick meshes of wire filter cloth are presented herein."
Air-Water Analogy and the Study of Hydraulic Models
From Summary: "The author first sets forth some observations about the theory of models. Then he established certain general criteria for the construction of dynamically similar models in water and in air, through reference to the perfect fluid equations and to the ones pertaining to viscous flow. It is, in addition, pointed out that there are more cases in which the analogy is possible than is commonly supposed."
An airborne indicator for measuring vertical velocity of airplanes at wheel contact
From Introduction: "The purpose of this paper is to describe one of the means developed for measuring this quantity on a given airplane type- a trailing arm with wheel. A prototype velocity indicator was tested in the Langley impact basin to determine its accuracy. A description of the operation of this type of vertical-velocity indicator, the results of the impact-basin and flight tests, and general evaluation of the indicator are presented herein."
Altitude evaluation of several afterburner design variables on a J47-GE-17 turbojet engine
From Introduction: "The investigation reported herein presents information on design factors and modifications of the production afterburner for the J47-GE-17 turbojet engine designed for medium temperature operation. The present report is concerned only with the afterburner performance and operating characteristics.Altitude-starting characteristics of two of the configurations in this report are discussed in reference 1."
Altitude Investigation of Several Afterburner Configurations for the J40-WE-8 Turbojet Engine
"An investigation was conducted in the Lewis altitude wind tunnel to evaluate the performance and operational characteristics of the J40-WE-8 afterburner. A brief program of minor modifications to the flame holder, diffuser, and fuel system was undertaken to improve at a burner-inlet pressure level of 620 pounds per square foot. At this pressure level, modifications to the fuel system resulted in an increase in maximum net thrust from 1500 to 1600 pounds and a reduction in specific fuel consumption in the stoichiometric region from 3.70 to 3.15 pounds of fuel per hour per pound of net thrust" (p. 1).
Altitude Investigation of Thrust Augmentation Using Water-Alcohol Injection Into the Combustion Chambers of an Axial-Flow Turbojet Engine
From Introduction: "The investigation reported herein, which was conducted in an NACA Lewis altitude test chamber, covered a range of altitudes from 30,000 to 50,000 feet at a flight Mach number of 0.8."
Altitude investigation of XJ34-WE-32 engine performance without electronic control
From Introduction: "As a part of the comprehensive investigation of the XJ34-WE-32 engine conducted in the NACA Lewis altitude wind tunnel, the over-all-performance was determined over a range of altitudes and flight Mach numbers. Other phases of the investigation are reported in reference 1. The results are given in tables and also in graphical form to show the trends of engine performance associated with changes of altitude, flight Mach number, and exhaust-nozzle area."
Altitude operational characteristics of prototype J40-WE-8 turbojet engine
From Introduction: "The altitude performance characteristics of the prototype J40-WE-8 turbojet engine were determined in the NACA Lewis altitude wind tunnel. The altitude operational characteristics of the engine are presented herein. The results of a brief study of the effect of the two different grades of fuel (MIL-F-5624A grades JP-3 and JP-4) on steady-state engine performance at an altitude of 45,000 feet and a flight Mach number of 0.20 are also given."
Altitude Performance and Operational Characteristics of YJ71-A-7 Turbojet Engine
"Altitude performance of a YJ71-A-7 turbojet engine, with afterburner inoperative, was determined in the NACA Lewis altitude wind tunnel over a wide range of flight conditions. Engine speed and exhaust-nozzle area were controlled independently during this investigation. The variation of corrected values of air flow, net thrust, and fuel flow with corrected engine speed was not defined by a single curve with changes in altitude at given flight Mach number" (p. 1).
Altitude performance characteristics of the J47-25 turbojet engine: data presentation
From Introduction: "An investigation was conducted in an NACA Lewis altitude chamber to determine the altitude performance characteristics of a J47-25 axial-flow turbojet engine over a range of engine-inlet Reynolds number indices corresponding to altitudes from 18,000 to 54,000 feet and flight Mach numbers from 0.50 to 1.10. Reynolds number at a given corrected engine speed and is a function only of engine-inlet total pressure and temperature, was used instead of various set altitudes and flight Mach number combinations (reference 1). An example is included in the appendix to illustrate the method of obtaining conventional performance parameters for a given flight condition from the data such as presented herein."
Altitude performance investigation of a high-temperature afterburner
From Introduction: "In response to the ever-increasing need for high thrust augmentation, an investigation was conducted that had as its primary objective the attainment of maximum exhaust-gas temperature and thrust (ref. 1). The investigation reported herein was therefore conducted to ascertain the operational limits of the most promising high-temperature afterburner design of reference 1 and to determine its performance over a wind range of flight conditions."
Altitude Performance Investigation of Two Single-Annular Type Combustors and the Prototype J40-WE-8 Turbojet Engine Combustor With Various Combustor-Inlet Air Pressure Profiles
Report presenting data obtained three single annular-type combustors with different combustor inlet-air pressure profiles over a range of engine speeds. Results regarding effect of changing combustor inlet-air pressure profile and hole geometry on combustor performance, performance of the prototype J40-WE-8 turbojet engine combustor, correlation of combustion efficiency with engine fuel-air ratio and combustion parameter, and comparison of several combustors from different turbojet engines are provided.
Altitude Performance of a 20-Inch-Diameter Ram-Jet Engine Investigated in a Free-Jet Facility at Mach Number 3.0
Report discussing the performance of a 20-inch-diameter ram-jet engine at Mach number 3.0 over a range of simulated altitudes from 60,500 to 66,500 feet. Information about the maximum combustor efficiency, range of exhaust-nozzle total pressures, lean blow-out, diffuser total-pressure recovery, and internal thrust coefficient is provided.
Altitude Performance of a 20-Inch-Diameter Ram-Jet Engine Investigated in a Free Jet Facility at Mach Number 3.0
Report presenting an investigation of the performance of a 20-inch-diameter ram-jet engine at Mach number 3.0 in a free-jet facility over a range of simulated altitudes. Results regarding the diffuser characteristics, combustor performance, thrust output, and operational characteristics are provided.
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. "
Altitude Wind Tunnel Investigation of the Prototype J40-WE-8 Turbojet Engine Without Afterburner
From Introduction: "As part of a comprehensive investigation of the J40 turbojet engine conducted at the NACA Lewis altitude wind tunnel, the steady-state engine performance of the prototype J40-WE-8 turbojet engine without afterburner was obtained and is presented herein. A basic redesign of the compressor and other modifications in the compressor and the combustor were incorporated in the XJ40-WE-6 turbojet engine (references 2 and 3). In this report the modified engine is designated "the prototype J40-WE-8 without afterburner."
Aluminum borohydride as an ignition source for turbojet combustors
From Introduction: "Problems associated with the use of aluminum borohydride for ignition in aircraft are discussed. A detailed description of its properties and results of static chamber tests to determine the effect of diluting aluminum borohydride with n-pentane on flammability in dry air are included in this investigation."
Analogy Between Mass and Heat Transfer with Turbulent Flow
From Introduction: "The purpose of this paper is to present an analysis of the mass- and heat-transfer process in terms of a simplified physical picture of the turbulent boundary layer subject to the assumptions previously described."
An Analysis of a Nuclear Powered Supercritical-Water Cycle for Aircraft Propulsion
Memorandum presenting an analysis to indicate the feasibility of the supercritical water compressor jet cycle for nuclear powered aircraft. Performance values of the cycle are given for a range of design-point engine operating conditions and subsonic flight conditions.
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."
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 laminar free-convection flow and heat transfer about a flat plate paralled to the direction of the generating body force
From Introduction: "Although the final equations obtained by this method are the same as those of Schmidt and Beckmann, this more general approach not only clearly demonstrates the significance of all the important parameters and assumptions and hence leads to a better understanding of this type of flow but also indicates the quantitative limitations of the theory. In addition, the numerical solutions of references 2 and 3 are herein extended to cover a more complete range of parameters."
Analysis of Landing-Gear Behavior
From Summary: "This report presents a theoretical study of the behavior of the conventional type of oleo-pneumatic landing gear during the process of landing impact. The basic analysis is presented in a general form and treats the motions of the landing gear prior to and subsequent to the beginning of shock-strut deflection."
Analysis of Multicell Delta Wings on Cal-Tech Analog Computer
"The main purpose of this paper is to present the results of measurements made on the Cal-Tech computer. The diagrams present only a small portion of the data which were obtained from the computer and which are given in complete form in the tables" (p. 1-2).
An analysis of normal-acceleration and airspeed data from a four-engine type of transport airplane in commercial operation on an eastern united states route from November 1947 to February 1950
Report presenting an analysis of 48,187 hours of normal-acceleration and airspeed data obtained on a four-engine type of transport airplane in commercial operation on an eastern United States route from November 1947 to February 1950 to determine gusts and gust loads for operations. Results regarding the presentation of data, effect of changes in operating conditions, effect of seasons, comparison with other results, reliability, acceleration, gusts, and airspeeds are provided.
Analysis of Off-Design Performance of a 16-Stage Axial-Flow Compressor With Various Blade Modifications
"The over-all performance of a 16-stage axial-flow compressor was determined with various stator-blade resettings and a reduction in solidity of the rotor blades in the last three stages. It was shown that little control over the sudden change in slope of the surge-limit line at intermediate speeds was obtained with the blade modifications attempted, except that some change in speed at which the change in slope occurred could be effected by stator-blade resettings" (p. 1).
Analysis of part-speed operation for high-pressure-ratio multistage axial-flow compressors
From Introduction: "For the analysis reported herein, the same hypothetical 12-stage compressor discussed in reference 6 was chosen, and the effects of inlet-stage stall characteristics and stage interactions were estimated by arbitrary adjustment of the stall characteristics and stage interactions were estimated by arbitrary adjustment of the stalled characteristics of the individual stages."
Analysis of several methods of pumping cooling air for turbojet engine afterburners
From Introduction: "Afterburning is well established as an effective means of increasing the thrust of a turbojet engine. In order to obtain the maximum thrust from an afterburner, it is necessary to burn to the highest temperatures possible (reference 1). At these high temperatures, material limitations (reference 2) necessitate the installation of cooling systems to permit safe and reliable operation."
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