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Wind-Tunnel Investigation at Low Speed of a Wing Having 63 Degree Sweepback and a Drooped Tip
From Summary: "The results of force tests made at low speed are presented to show the effect of longitudinal static stability produced by drooping the tip of a 63 degree sweptback wing. Five semispan wing models were tested: two incorporated curved drooped tips, two with abruptly drooped tips, and one without droop. The most favorable stability characteristics were measured for a model with an abruptly drooped tip, a fence, and a leading-edge flap; however, the use of these same auxiliary devices on the undrooped wing was nearly as effective."
Component Operating Trends During Acceleration and Deceleration of Two Hypothetical Two-Spool Turbojet Engines
Memorandum presenting an investigation of the compressor and turbine operating trends during acceleration and deceleration of two hypothetical two-spool turbojet engines. The two engines have the same component performance maps but the arbitrarily specified ratio of outer- to inner-spool moment of inertia for the second engine is 4 times that specified for the first engine. Results regarding the acceleration characteristics and deceleration characteristics are provided.
An experimental investigation of two methods for reducing transonic drag of swept-wing and body combinations
Report presenting an investigation of a wing swept back 35 degrees in combination with one basic body and three modified bodies at a range of Mach numbers from 0.60 to 1.20. Results regarding force studies and pressure studies are provided. The bodies modified according to the Kuchenmann ring-vortex method resulted in superior aerodynamic characteristics except with regard to zero-lift drag at high supersonic Mach numbers.
Lift, drag, and static longitudinal stability characteristics of four airplane-like configurations at Mach numbers from 3.00 to 6.28
Report presenting lift, drag, and pitching-moment coefficients, lift-drag ratios, and center-of-pressure positions for four airplane-like configurations determined from tests at a range of Mach numbers and angles of attack. The wings and nose shapes were modified for each of the configurations.
Effect of Design Compressor Pressure Ratio on Performance of Hypothetical Two-Spool Nuclear-Powered Turbojet Engines
Memorandum presenting hypothetical two-spool nuclear-powered turbojet engines with sea-level static design compressor total-pressure ratios of 20, 15, and 9 and total-pressure losses between the inner-spool compressor exit and turbine inlet of 10 and 30 percent. Results regarding compressor operating lines, gas-generator performance, engine performance, and some general remarks are provided.
Flight investigation of pentaborane fuel in 9.75-inch-diameter ram-jet engine with downstream fuel injection
Report presenting a flight test of pentaborane fuel in an air-launched ramjet engine with a design free-stream Mach number of 1.8. The ramjet used in the investigation had a revised spray bar-flameholder configuration. Results regarding propulsive thrust and propulsive-thrust specific fuel consumption are provided.
Effect on the low-speed aerodynamic characteristics of a 49 degree sweptback wing having an aspect ratio of 3.78 of blowing air over the trailing-edge flap and aileron
Report presenting an investigation in the full-scale tunnel to determine the effects on the aerodynamic characteristics of a 49.1 degree sweptback wing of blowing a high-energy stream of air over a trailing-edge flap and an aileron. The results indicated that significant increases in lift coefficient and an improvement in aileron effectiveness may be obtained by the blowing method of boundary-layer control.
Investigation of the aerodynamic and icing characteristics of a recessed fuel cell vent assembly 3: NACA flush-inlet-type vent
An investigation conducted in the icing research tunnel to determine aerodynamic and icing characteristics of two flush-inlet-type fuel cell vent installations. The vent tubes were mounted in two different locations in the two installations. The vents were aerodynamically investigated to obtain vent-tube static-pressure differentials and pressure surveys as a function of tunnel-air velocity and angle of attack.
Pressure recovery at supersonic speeds through annular duct inlets situated in a region of appreciable boundary layer 1: addition of energy to the boundary layer
Report presenting a model with a nozzle upstream of an annular duct inlet for the purpose of ejecting high-velocity air into the boundary layer of the flow along the forebody tested between Mach numbers of 1.36 and 2.01. Results wind-tunnel data, equivalent pressure recovery, and scale effects are provided.
Empirical mode constants for calculating frequencies of axial-flow compressor blades
The vibration characteristics of a group of axial-flow compressor blades of similar geometry were investigated. Empirical-mode constants were determined for the first three bending and torsional modes. A comparison of experimentally determined frequencies of a second group of blades with frequencies computed using these mode constants showed that the computed values were correct within 10 percent. The approximate limiting ratios of depth to chord and length to chord below which these constants could not be used to compute the natural frequencies were also found experimentally.
Flight Tests to Determine the Drag of Fin-Stabilized Parabolic Bodies at Transonic and Supersonic Speeds
Report presenting testing on parabolic bodies of revolution of two fineness ratios in the transonic and supersonic range. One had a body fineness ratio of 7.87 and one had a ratio of 12 and were tested under different Mach number ranges. Experimental results and drag estimates of various portions of the body are provided.
Results Obtained During Accelerated Transonic Tests of the Bell XS-1 Airplane in Flights to a Mach Number of 0.92
Results are presented of tests up to a Mach number of 0.92 at altitudes around 30,000 feet. The data obtained show that the airplane can be flown to this Mach number above 30,000 feet. Longitudinal trim changes have been experienced but the forces involved have been small. The elevator effectiveness decreased about one-half with increase of Mach number from 0.70 to 0.87.
Stability Results Obtained With Douglas D-558-1 Airplane (BuAero No. 37971) in Flight Up to a Mach Number of 0.89
Memorandum presenting measurements of some of the high-speed characteristics of the D-558-1 airplane up to Mach number 0.89. The results of the tests showed that the stabilizer incidence drastically affected the longitudinal trim characteristics above a Mach number of 0.80.
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.
Evaluation of Gust and Draft Velocities From Flights of F-61C Airplanes Within Thunderstorms August 21, 1947 to August 25, 1947 at Clinton County Army Air Field, Ohio
Memorandum presenting the results of measurements of gust and draft velocities within thunderstorms at a selected air field over a 5-day period. They are also compared to previous flights.
General handling-qualities results obtained during acceptance flight tests of the Bell XS-1 airplane
Report presenting measurements of the handling qualities of the Bell XS-1 transonic airplane using NACA instruments. Information regarding the stability and control characteristics and aerodynamic loads was obtained using two different airplanes in gliding and powered flight. Results regarding the longitudinal and lateral stability and control and stalling characteristics are provided.
Results of Preliminary Flight Tests of the XS-1 Airplane (8-Percent Wing) to a Mach Number of 1.25
Presents results of the U. S. Air Forces' accelerated transonic flight tests of the XS-1 No. 1 airplane for the Mach number range from 0.70 to 1.25 at altitudes from 30,000 to 49,000 feet. Data are included on horizontal-tail loads and buffeting, longitudinal trim changes, elevator effectiveness and control forces, and lateral trim characteristics.
Preliminary investigation of control characteristics at transonic speeds of a tapered 45 degree sweptback wing of aspect ratio 3 having a horn-balanced full-span control
Report presenting an investigation at transonic speeds in the 7- by 10-foot tunnel to determine hinge-moment and effectiveness characteristics of a horn-balanced control on an aspect-ratio-3, 45 degree sweptback wing. The investigation was extended through the transonic speed range by testing in the high velocity field over a reflection plane on the sidewall of the tunnel.
Lift, drag, and pitching moment of low-aspect-ratio wings at subsonic and supersonic speeds: Twisted and cambered triangular wing of aspect ratio 2 with NACA 0005-63 thickness distribution
Report presenting the results of a wind-tunnel investigation at subsonic and supersonic Mach numbers to determine the aerodynamic characteristics of a wing-body combination with a triangular wing of aspect ratio 2. The mean surface of the wing was twisted and cambered to support a nearly elliptical span load distribution at Mach number 1.53 and a lift coefficient of 0.25. Lift, drag, and pitching moment are presented for a range of Mach and Reynolds numbers.
Experimental investigation of the drag of 30 degree, 60 degree, and 90 degree cone cylinders at Mach numbers between 1.5 and 8.2
Report presenting the total drag coefficients of 60 degree cone cylinders of fineness ratio 2.07 measured in free flight from Mach numbers of 1.5 to 8.2. Results regarding the smooth 60 degree cone cylinder, rifled models, and discontinuity lines in the shadowgraph pictures are provided.
Low-speed aerodynamic characteristics of a large-scale 45 degree swept-back wing with partial-span slats, double-slotted flaps, and ailerons
Report presenting experimental data from force and pressure tests on a large-scale, semispan, wing-fuselage model. Longitudinal force and moment characteristics are given for the model with various combinations of slat spans. The wing had 45 degrees of sweepback, an aspect ratio of 6, a taper ratio of 0.5, and an NACA 64A010 section normal to the quarter-chord line of the unswept panel and had partial-span slats, aileron, and double-slotted flaps equipped.
Matched performance characteristics of a 16-stage axial-flow compressor and a 3-stage turbine
Report presenting component performance data for one modification of a 16-stage compressor and a 3-stage turbine to determine the matched performance characteristics of an engine with those components. The compressor surge line and infinite exhaust-nozzle-area equilibrium operating line restricted the region of matched compressor-turbine operation. Results regarding the engine operation with modified compressor and three-stage turbine, effect of leakage on engine operation, component efficiencies, and operation in the surge region are provided.
Longitudinal Stability and Drag Characteristics at Mach Numbers From 0.75 to 1.5 of an Airplane Configuration Having a 60 Degree Swept Wing of Aspect Ratio 2.24 as Obtained From Rocket-Propelled Models
Report discussing testing of a rocket-propelled airplane configuration model and a drag model, each with a 60 degree swept wing of aspect ratio 2.24, and different fuselages, at a Mach number range of 0.75 to 1.50. Information about the longitudinal stability, control, and drag characteristics and minimum-drag characteristics is presented.
Wind-Tunnel Investigation at Low Speed of the Effects of Symmetrical Deflection of Half-Delta Tip Controls on the Damping in Roll and Yawing Moment Due to Rolling of a Triangular-Wing Model
Report presenting a low-speed investigation in the stability tunnel to determine the effects of symmetrical deflection of half-delta tip controls on the damping in roll and yawing moment due to rolling of a model with triangular wings. Triangular wings have numerous aerodynamic advantages, but it is difficult to obtain adequate longitudinal and lateral control with acceptable control forces when using them. Results regarding the lift characteristics and rolling characteristics are provided.
Investigation of the hydrodynamic stability and resistance of two streamline fuselages
Report presenting an investigation of a dynamic model to determine the effects of hull form, gross load, and aerodynamic trimming moments on the trim limits, trim, hydrodynamic moment, hydrodynamic resistance, total resistance, and rise of two streamline fuselages modified by chine strips. Results regarding effects of hull form and effects of gross load are provided.
Transonic Drag Characteristics and Pressure Distribution on the Body of a Wing-Body Combination Consisting of a Body of Revolution of Fineness Ratio 12 and a Wing Having Sweepback of 45 Degrees, Aspect Ratio 4, Taper Ratio 0.6, and NACA 65A006 Airfoil Sections
Report presenting free-fall testing of the airplane configuration described in the title to evaluate certain new testing techniques for near sonic speeds. Results regarding the drag measurements and pressure data are provided. The data obtained from this test is also compared to free-fall tests in the high-speed tunnel and for a rocket-powered free-flight model, and the results show generally satisfactory agreement.
The effect of bluntness on the drag of spherical-tipped truncated cones of fineness ratio 3 at Mach numbers 1.2 to 7.4
Report presenting an investigation of the drag of spherically blunted conical models of fineness ratio 3 at a range of Mach and Reynolds numbers. Results of the tests showed that slightly blunted models had less drag than cones of the same fineness ratio through the Mach number range. Results regarding the total drag, wave drag, and viscous effects are provided.
Internal-film-cooling experiments with 2- and 4-inch smooth-surface tubes and gas temperatures to 2000 degrees Fahrenheit
Report presenting an investigation of liquid-film cooling at a variety of air temperatures and Reynolds numbers. Results regarding the effect of coolant flow per circumferential length on liquid-cooled length, correlation of heat transfer from hot gas to liquid film for constant coolant flow per circumferential length, and generalized plot of film-cooling data based on heat-transfer correlation at constant coolant flow per circumferential length are provided.
Preliminary investigation of the drag characteristics of the NACA RM-10 missile at Mach numbers of 1.40 and 1.59 in the Langley 4- by 4-foot tunnel
Report presenting testing of a parabolic body of revolution in the 4- by 4-foot supersonic tunnel at two Mach numbers. The investigation included the effects of Reynolds number, fins, internal contour of body base, and two support systems on body pressure and force drag at an angle of attack of 0 degrees.
Performance of an impulse-type supersonic compressor with stators
Report presenting testing of an impulse-type supersonic compressor rotor with stators tested in Freon-12 over a range of equivalent tip speeds and weight flows. A static pressure ratio of 1.83 and an efficiency of 84.7 percent were obtained at 69.1 percent of the design speed of 1604 feet per second in air.
Relations between fuel properties and combustion carbon deposition
Report discussing some methods for predicting the carbon-forming propensity of turbojet-engine fuels from results of simple laboratory tests of the fuels. The prediction of carbon deposition from fuel characteristics including aromatic content, hydrogen-carbon ratio, distillation temperatures, gravity, and aniline point from several empirical laboratory carbon-deposition tests are provided. Results regarding fuel composition and volatility, related fuel properties, empirical laboratory tests, a comparison of methods predicting carbon-deposition characteristics of fuels, and application of fuel quality control methods are provided.
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).
Preliminary investigation at transonic speeds of the effect of balancing tabs on the hinge-moment and other aerodynamic characteristics of a full-span flap on a tapered 45 degree sweptback wing of aspect ratio 3
Report presenting an investigation at transonic speeds of the control balancing characteristics of three tabs on a full-span flap on an aspect-ratio-3, 45 degree sweptback wing. The results indicated that all the tabs tested, inset, attached, or detached, would balance the flap hinge moments throughout the speed range.
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."
Low speed stability characteristics of a complete model with a wing of W plan form
Report presenting an investigation of the low-speed static stability characteristics of a complete model equipped with a W wing. The lift-curve slope of the wing-fuselage combination was found to be in good agreement with that predicted by available wing-alone theory. Results regarding the longitudinal characteristics, wing-juncture modifications, and lateral and directional stability characteristics are provided.
Full-scale wind-tunnel investigation of the effects of wing modifications and horizontal-tail location on the low-speed static longitudinal characteristics of a 35 degree swept-wing airplane
Report presenting tests made in the 40- by 80-foot wind tunnel to evaluate the effects of wing modifications on the static longitudinal characteristics of a 35 degree swept-wing airplane. The wing modifications were designed to replace existing wing slats as low-speed high-lift devices. Results regarding the two-dimensional tests, full-scale tests, design of wing modification 1, test results of the airplane, and a comparison of test results with predictions are provided.
Some factors affecting fabrication and high-temperature strength of molybdenum disilicide
Report presenting an investigation of the properties of molybdenum disilicide in which a fine-grain material and a large-grain material were produced using different methods. Results regarding the fine-particle sintered material, coarse-grain, hot-pressed material, a comparison of the two materials, and the effect of oxygen on sintering and mechanical properties are provided.
Application of supersonic vortex-flow theory to the design of supersonic impulse compressor- or turbine-blade sections
From Introduction: "The purpose of this paper is to present an analytical method for the design of two-dimensional related selection of a blade for particular rotor conditions may be made quickly and easily and its performance deduced from tests of representative sections in cascade."
Investigation of a 10-Stage Subsonic Axial-Flow Research Compressor 1: Aerodynamic Design
Memorandum presenting a 10-stage axial-flow compressor designed for use as a research unit in which the problems associated with the compounding of high performance stages could be studied. The overall performance characteristics of the compressor, as determined experimentally, are included.
The effects on the aerodynamic characteristics of varying the wing thickness ratio of a triangular wing-body configuration at transonic speeds from tests by the NACA wing-flow method
Testing occurred using the NACA wing-flow method at a range of Mach numbers to determine the aerodynamic characteristics of three triangular wing-fuselage models which differed only in wing thickness-chord ratio. The wings had an aspect ratio of 2.31 with 6-, 9-, and 12-percent-thick biconvex sections and a fuselage with a fineness ratio of 12. Results regarding the normal force, chord force, and pitching moment for various angles of attack.
Wing load distribution on a swept wing airplane in flight at Mach numbers up to 1.11, and comparison with theory
Report presenting flight tests to determine the pressure distribution over the wing of a swept-wing jet-propelled airplane over the flight range of lift coefficients for Mach numbers up to 1.11. Results regarding the section characteristics, load distribution, and trailing-edge loads are provided.
Some Effects of Changing Solidity by Varying the Number of Blades on Performance of an Axial Flow Compressor Stage
Report presenting an investigation to determine some of the basic problems and effects involved in a change of solidity accomplished by a change in the number of blades in an axial-flow-compressor rotor row and in a complete stage. Results regarding rotor performance and complete stage performance are provided.
Preliminary investigation of the altitude performance of pentaborane and a pentaborane : JP-4 blend in an experimental 9.5-inch-diameter tubular combustor
From Summary: "A preliminary investigation was conducted to determine the altitude performance of pentaborane and a blend fuel of 64.2 percent pentaborane in JP-4 fuel in a tubular combustor of a current production type turbojet engine. Deposits on the liner barrel and dome were virtually nonexistent. The combustion efficiency of 90 to 94 percent for pentaborane and approximately 90 percent for the blend. Outlet temperature profiles were marginal; however, the developed combustor provided lower pressure losses than obtained in conventional combustors."
An Experimental Investigation of the Combustion Properties of a Hydrocarbon Fuel and Several Magnesium and Boron Slurries
Memorandum presenting an investigation conducted to explore the characteristics of metal-hydrocarbon combustion, to determine the effect of fuel-air ratio on the combustion efficiency, and to determine how the metal and hydrocarbon separately contribute to the overall combustion of several slurries. Results regarding an evaluation of the sampling method, combustion efficiency, effective metal weight fraction, effective hydrogen-carbon ratio, and heat of combustion per pound of air are provided.
An approximation to the effect of geometric dihedral on the rolling moment due to sideslip for wings at transonic and supersonic speeds
Report presenting a simple geometric relation that allows the effect of geometric dihedral on the rolling moment due to sideslip at transonic and supersonic speeds to be estimated if the damping in roll or rolling moment due to differential wing incidence is known. There is no experimental information available to check certain equations, but the approximations look promising at this time.
Gust-Tunnel Investigation of a Delta-Wing Model With the Leading Edge Swept Back 60 Degrees
Report discussing an investigation of a delta-wing model with the leading edge swept back 60 degrees. Testing indicated that the gust load is greater than would be predicted by using a slope of the lift curve determined from steady-flow force tests. An aspect-ratio relation was determined for this type of wing with the selected apex angle, but it does not appear to be applicable to other wings with different apex angles.
Wind-tunnel investigation of the aerodynamic characteristics in pitch of wing-fuselage combinations at high subsonic speeds: Aspect-ratio series
Report presenting an investigation in the 7- by 10-foot tunnel to determine the effect of aspect ratio on the aerodynamic characteristics in pitch of wing-fuselage combinations with 45 degrees sweepback at the quarter-chord line and 0.6 taper ratio at high subsonic speeds. Results regarding the lift characteristics, pitching-moment characteristics, drag characteristics, and lift-drag ratios are provided.
Instrumentation of the Ames Supersonic Free-Flight Wind Tunnel
Memorandum presenting a description of the equipment used in the Ames supersonic free-flight wind tunnel to obtain the data necessary to measure the aerodynamic characteristics of free-flying models. The model is fired from a gun into the supersonic air stream of a blowdown-type wind tunnel. The action resulting from aerodynamic forces is computed from a time-distance-attitude record of the model flight through the test section.
Effect of inlet air and fuel parameters on smoking characteristics of a single tubular turbojet engine combustor
Report presenting an investigation to determine the effect of systematic variations in inlet-air and fuel parameters on the smoking characteristics of a single tubular turbojet-engine combustor. The most pronounced effect on smoke was observed with increase in inlet-air pressure which produced large increases in smoke concentration. Results regarding the reproducibility of smoke measurements, effect of fuel-air ratio and inlet-air parameters on smoke density, effect of fuel parameters on smoke density, full-scale engine tests, and combustion efficiency are provided.
Damping in Pitch of Low-Aspect-Ratio Wings at Subsonic and Supersonic Speeds
Memorandum presenting the application of the concept of indicial functions to the analysis of the aerodynamic phenomena associated with the short-period pitching mode of wings in subsonic and supersonic flight. Simple physical relationships are pointed out and are used to study the effect on the rotary-damping-moment coefficient of changes in center-of-gravity position, Mach number, aspect ratio, plan form, frequency, and thickness.
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