Technical Report Archive & Image Library (TRAIL) - 440 Matching Results
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- Average Outside-Surface Heat-Transfer Coefficients and Velocity Distributions for Heated and Cooled Impulse Turbine Blades in Static Cascades
- Heat-transfer investigation conducted on cooled as well heated impulse-type turbine blades in a static cascade to determine the effect of direction of heat flow on convective heat-transfer coefficients.
- Investigation of turbines suitable for use in a turbojet engine with high compressor ratio and low compressor-tip speed 5: experimental performance of two-stage turbine with downstream stator
- An experimental investigation of a highly loaded two-stage turbine with a downstream stator revealed that (1) at equivalent design work and speed the brake internal efficiency was 0.81 and the maximum efficiency obtained was 0.85, and (2) the downstream stator left very little energy in the form of tangential velocity in the gas and, in general, performed well with 0.78 recovery being obtained at equivalent design work and speed.
- Investigation of altitude ignition, acceleration and steady-state operation with single combustor of J47 turbojet engine
- Report describing an investigation conducted with a single combustor from a J47 turbojet engine using weathered aviation gasoline and several spark-plug modifications to determine altitude ignition, acceleration, and steady-state operating characteristics. Results regarding ignition, acceleration, altitude operational limits, combustion efficiency, and pressure loss are provided.
- Free-Jet Tests of a 6.5-Inch-Diameter Ram-Jet Engine at Mach Numbers 1.81 and 2.00
- Report presenting testing of a 6.5-inch-diameter ramjet engine with a design Mach number of 2.13 and a short-flame-length combustor. Performance characteristics are provided for a range of Mach numbers and fuel-air ratios. Results regarding thrust, drag tests, static pressure, and combustion efficiencies are provided.
- An investigation of the control-surface flutter derivatives of an NACA 65(sub 1)-213 airfoil in the Ames 16-foot high-speed wind tunnel
- Report presenting a determination of control-surface flutter derivatives for a sinusoidally oscillating control surface mounted on a two-dimensional fixed airfoil for a range of reduced frequency. Results regarding subsonic results and transonic results are provided.
- Experimental investigation of air-cooled turbine blades in turbojet engine 9: evaluation of the durability of noncritical rotor blades in engine operation
- The durability of five different structural or cooling configurations or combination of both of air-cooled blades made of noncritical materials was investigated in a modified turbojet engine. The greater part of the investigation was conducted at an engine speed of 11,500 rpm, a turbine-inlet temperature of approximately 1670 degrees F, and a cooling-air to combustion gas flow ratio per blade of 0.05. The results of the investigation indicated that air-cooled blades made of noncritical metals can be operated for extended periods of time in engines at current inlet temperatures; however, before these blades are considered completely satisfactory for gas-turbine application, some means such as coatings is required to inhibit the oxidation of the blades.
- Free-Spinning Tunnel Investigation of a 1/20-Scale Model of the Douglas X-3 Airplane
- Report discussing the spin and spin-recovery characteristics of a model of the Douglas X-3 airplane in a free-spinning tunnel. The pitching-moment characteristics of the scale model were not found to be typical of larger scale results. The results indicated that at an altitude range of 15,000 to 30,000 feet, the X-3 will not exhibit unusual trim tendencies and it will be difficult to obtain erect spins unless the ailerons are full with the spin.
- Preliminary Investigation of the Effects of Rectangular Vortex Generators on the Performance of a Short 1.9:1 Straight-Wall Annular Diffuser
- Report presenting a preliminary investigation in a duct system with fully developed pipe flow to determine the effectiveness of vortex generators in improving the performance of a 21-inch-diameter straight-outer-wall annual diffuser with an overall equivalent conical expansion angle of 15 degrees and a and 1.9:1 area ratio. The vortex generators used were rectangular noncambered airfoils that varied in chord, span, angle of attack, number, and location. Results regarding a diffuser with no vortex generators, a diffuser with vortex generators on inner body, and a comparison of the diffuser performance with and without vortex generators are provided.
- Preliminary investigation of the pressure fluctuations in the wakes of two-dimensional wings at low angles of attack
- Report presenting a measurement of the magnitudes of pressure fluctuations in the turbulent wakes of restrained two-dimensional airfoils at transonic speeds. Measurements indicated that the total-pressure fluctuations occurred only within the wake. Results regarding the magnitude of pressure oscillation in the wake, effect stream-angle fluctuations in the wake, and frequencies of pressure oscillation on the wing and in the wake are provided.
- A Relation of Wind Shear and Insolation to the Turbulence Encountered by an Airplane in Clear-Air Flight at Low Altitudes
- Memorandum presenting the observed gust experience of an airplane and information on the associated meteorological conditions to obtain a simple empirical relation for estimating the intensity of turbulence in the earth's friction layer. The relation does not discriminate between differences in turbulence intensity resulting from variations of flight altitude or diurnal variations of turbulence.
- Effects of double-slotted flaps and leading-edge modifications on the low-speed characteristics of a large-scale 45 degrees swept-back wing with and without camber and twist
- Report presenting an investigation of two large-scale, semispan, wing-fuselage models with the 0.25-chord line swept back 45 degrees to determine and compare the effects of partial-span, double-slotted flaps on the characteristics of a 45 degree sweptback wing with and without camber and twist. A secondary investigation was also conducted to determine the effects of various full-span, leading-edge modifications on the characteristics of the models with and without the flaps.
- Free-spinning tunnel investigation of the 1/21-scale model of the Chance Vought F7U-3 airplane: TED No. NACA DE 362
- Report presenting an investigation of a 1/21-scale model of the Chance Vought F7U-3 airplane in the 20-foot free-spinning tunnel to determine the erect and inverted spin and recovery characteristics for combat loading in the clean condition. Results regarding erect spins, inverted spins, spin-recovery parachutes, and recommended recovery technique are provided.
- Investigation of a 24-inch shock-in-rotor type supersonic compressor designed for simple radial equilibrium behind normal shock
- A 24-inch-diameter shock-in-rotor supersonic compressor rotor designed to obtain simple radial equilibrium behind the normal shock obtained a maximum total-pressure ratio of 2.02 at an adiabatic efficiency of 0.74 and a weight flow of 61.5 pounds per second at design speed. Although this design method considerably reduced the radial forces, there was no apparent reduction in the radial forces, there was no apparent reduction in the radial redistribution of mass flow over the radial redistribution obtained in the previous investigation. This investigation indicates that the shock boundary-layer interaction pattern and associated effects have a very large effect on the radial redistribution of mass flow through the shock-in-rotor supersonic-compressor rotor.
- Additional Studies of the Stability and Controllability of an Unswept-Wing Vertically Rising Airplane Model in Hovering Flight Including Studies of Various Tethered Landing Techniques
- Report discussing the results of an investigation to determine the stability and control characteristics of a flying model of an unswept-wing vertically rising airplane. Information about stabilization, maneuverability, rolling motions, and landings is provided.
- Flight Investigation of the Longitudinal Stability and Control Characteristics of the Douglas D-558-I Airplane (BuAero No. 37972) at Mach Numbers Up to 0.89
- Report presenting results and analysis of the longitudinal stability and control characteristics of the Douglas D-558-I airplane at a range of altitudes and Mach numbers. It was found that large and rapid changes in elevator deflection and force were required for balance at Mach numbers above 0.84 due to a sharp decrease in elevator-stabilizer effectiveness.
- A Wind-Tunnel Investigation of the Static Stability Characteristics of a 1/8-Scale Ejectable Pilot-Seat Combination at a Mach Number of 0.8
- Report presenting an investigation of a model of an ejectable pilot seat combination with and without stabilizing fins. The main purpose of the investigation was to determine the static aerodynamic characteristics and effectiveness of various stabilizing fins at a high subsonic Mach number. Results regarding stability and force characteristics for the combinations are provided.
- Some Effects of Spanwise Aileron Location and Wing Structural Rigidity on the Rolling Effectiveness of 0.3-Chord Flap-Type Ailerons on a Tapered Wing Having 63 Degrees Sweepback at the Leading Edge and Naca 64A005 Airfoil Sections
- Report presenting an investigation of some effects of aileron spanwise location and wing structural rigidity on the rolling power of 0.3-chord plain, flap-type ailerons on a wing with a taper ratio of 0.25, an aspect ratio of 3.5, and swept back 63 degrees at the leading edge. Results regarding the aeroelastic effects and aileron span and spanwise location are provided.
- Stability and Control Measurements Obtained during USAF-NACA Cooperative Flight-Test Program on the X-4 Airplane (USAF No. 46-677)
- Memorandum presenting results obtained during Air Force testing of the Northrop X-4 airplane. Information is included on the stalling characteristics, the static and dynamic longitudinal and lateral-stability characteristics, and the lateral-control characteristics.
- Elevated Temperature Properties of Titanium Carbide Base Ceramals Containing Nickel or Iron
- Elevated-temperature properties of titanium carbide base ceramals containing nickel or iron were determined in oxidation, modulus of rupture, tensile strength, and thermal-shock resistance. These materials followed the general growth law and exhibited two stages in oxidation. The following tensile strengths were found at 2000 degrees F: 13.3 weight percent nickel, 16, 150 pounds per square inch; 11.8 weight percent iron, 12,500 pounds per square inch; unalloyed titanium carbide, 16,450 pounds per square inch. Nickel or iron additions to titanium carbide improved the thermal-shock resistance, nickel more. The path of fracture in tensile and thermal-shock specimens was found to progress approximately 50 percent intergranularly and 50 percent transgranularly.
- Flame velocities over a wide composition range for pentane-air, ethylene-air, and propyne-air flames
- Fundamental flame velocities are reported for pentane air, ethylene-air, and propylene-air mixtures for the concentration range 60 to 130 percent of stoichiometric. A form of the Tanford and Pease equation, which includes a small constant velocity term independent of diffusion, will predict the observed changes in flame velocity.
- Properties of Low-Carbon N-155 Alloy Bar Stock From 1200 to 1800 Degrees Fahrenheit
- Memorandum presenting the results of an investigation to establish rupture and total-deformation strengths at 1200 and 1800 degrees Fahrenheit for typical commercial treatments of low-carbon N-155 alloy. The results show that there were large differences in strength between the heats of bar stock at temperatures above 1200 degrees Fahrenheit except when a 2200 degree Fahrenheit solution treatment was used.
- Determination and Use of the Local Recovery Factor for Calculating the Effectiveness Gas Temperature for Turbine Blades
- In an experimental investigation of local recovery factors for a blade having a pressure distribution similar to that of a typical reaction-type turbine blade, it a was found that the recovery factors were essentially independent of Mach number, Reynolds number, pressure gradient, and position on the blade surface except for regions where the boundary layer was probably in the transition range from laminar to turbulent. The recommended value of local subsonic recovery factor for use in calculating the effective gas temperature for gas turbine blades was 0.89.
- Experimental investigation of typical constant- and variable-area exhaust nozzles and effects on axial-flow turbojet-engine performance
- Report presenting testing of several turbojet engines with both constant- and variable-area nozzles to extend full-scale nozzle performance to higher exhaust-nozzle pressure ratios and to investigate the effects of constant- and variable-area nozzles on turbojet-engine operation. Results regarding the different types of nozzles are provided.
- An Investigation of the Longitudinal Characteristics of the X-3 Configuration With Wing and Horizontal Tail Surfaces of Aspect Ratio 3.0 by Means of Rocket-Propelled Models: Results at High Lift Coefficients
- "A rocket-propelled model of the X-3 configuration equipped with an all-movable tail of aspect ratio 3.0 has been flown to determine the longitudinal characteristics of this configuration at high lift coefficients. An analysis of the response of the model to rapid deflections of the horizontal tail gave information on lift, drag, longitudinal stability, and longitudinal trim change. The primary result of the tests was that the configuration was indicated to have very unstable tendencies at lift coefficients above the stall and at Mach number near 0.7" (p. 1).
- Correlation of Analog Solutions With Experimental Sea-Level Transient Data for Controlled Turbine-Propeller Engine, Including Analog Results at Altitudes
- Memorandum presenting a satisfactory correlation obtained between experimental sea-level transient data at constant flight speed and solutions from the analog representation. The representation is accomplished by transfer functions formed from a frequency-response analysis, which is then used to compute system response at altitude.
- Estimation of Neutron Energy for First Resonance From Absorption Cross Section for Thermal Neutrons
- Examination of published data for some 52 isotopes indicates that the neutron energy for which the first resonance occurs is related to the magnitude of the thermal absorption cross section. The empirical relation obtained is in qualitative agreement with the results of a simplified version of the resonance theory of the nucleus of Breit-Wigner.
- An Investigation of Four Wings of Square Plan Form at a Mach Number of 6.86 in the Langley 11-Inch Hypersonic Tunnel
- Report presenting the results of pressure-distribution and force tests on four wings at Mach number 6.86 and Reynolds number 980,000 in the 11-inch hypersonic tunnel. Characteristics of the wings tested included a 4-inch square plan form, a 5-percent maximum thickness, and diamond, half-diamond, wedge, and half-circular-arc sections. Information about pressure measurements, wing characteristics, and Schlieren photographs is provided.
- 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.
- A simplified instrument for recording and indicating frequency and intensity of icing conditions encountered in flight
- "An instrument for recording and indicating the frequency and intensity of aircraft icing conditions encountered in flight has been developed by the NACA Lewis Laboratory to obtain statistical icing data over world-wide air routes during routine airline operations. The operation of the instrument is based on the creation of a differential pressure between an ice-free total-pressure system and a total-pressure system in which small total-pressure holes vented to static pressure are allowed to plug with ice accretion. The simplicity of this operating principle permits automatic operation, and provides relative freedom from maintenance and operating problems" (p. 1).
- Effect of the Proximity of the Ground on the Stability and Control Characteristics of a Vertically Rising Airplane Model in the Hovering Condition
- Report discussing the effect of the proximity of the ground on the stability and control characteristics of a vertically rising airplane model in the hovering condition. The dynamic behavior of the model in take-offs and landings and when it was hovering near the ground was also investigated. Force tests to determine the change in the vertical-tail yawing moments with control deflection and with angle of yaw for various heights were also conducted.
- Rolling Effectiveness of All-Movable Wings at Small Angles of Incidence at Mach Numbers From 0.6 to 1.6
- "Experimental data have been obtained of the rolling effectiveness of several all-movable wing configurations by means of rocket-propelled test vehicles in free flight. The results are compared with some available methods of estimation. These results validate the use of the simple equation derived by a strip integration and originally presented in NACA RM L50G14b over a wide range of application as a means of estimating the rolling effectiveness of all-movable wings" (p. 1).
- Analytical investigation of flow through high-speed mixed-flow turbine
- From Introduction: "Good experimental correlation of the analytical results was obtained for the compressor even though isentropic flow and axial symmetry were assumed (reference 1). In order to determine the flow through the turbine being investigated, however, it was necessary to extend the method of reference 1 to include the flow downstream of the rooter since the large blade taper and hub-shroud curvature caused downstream conditions which affected the flow inside the rotor."
- Investigation at Mach Number 1.88 of Half of a Conical-Spike Diffuser Mounted as a Side Inlet With Boundary-Layer Control
- Experimental investigation was conducted at Mach number 1.88 to determine performance characteristics of half a 50 degree-conical-spike inlet mounted on a flat plate. Initial boundary layer was removed up-stream of inlet by a ram-type scoop of variable height. Initial boundary-layer thickness was also varied. With complete removal of initial boundary layer, total-pressure recovery of approximately 70 percent. Several alternative boundary-layer-removal systems were investigated which decreased the adverse effect of operating the ram scoop sub-critically.
- Damping in Roll of Rocket-Powered Test Vehicles Having Swept, Tapered Wings of Low Aspect Ratio
- "Flight tests of rocket-powered models have been conducted to determine the damping in roll of a group of swept, tapered wings designed for flight in the transonic speed region. The Mach number range of these tests was from approximately 0.7 to 1.4. The experimental damping in roll for all configurations was less than predicted by linearized theory throughout the Mach umber range of these tests. The only wing in this group that experienced an appreciable transonic lateral trim change was the one with a 7-percent-thick circular-arc airfoil section" (p. 1).
- Schlieren investigation of the wing shock-wave boundary-layer interaction in flight
- Report presenting data obtained in flight using a schileren apparatus that photographed the shock-wave interaction with a thick turbulent boundary layer on a wing. Local Mach number and boundary-layer characteristics obtained from pressure measurements in the vicinity of the shock wave are also presented.
- Effects of Reynolds Number on the Aerodynamic Characteristics of a Delta Wing at Mach Number of 2.41
- Memorandum presenting the results of an experimental investigation to determine the effects of Reynolds number on the flow characteristics over a delta wing at a Mach number 2.41. The wing streamwise airfoil sections are based on the NACA 00-thickness series with the maximum thickness varying from 4 percent at the root section to 6.24 percent at the 90-percent spanwise station. Results regarding force data and pressure-distribution data are provided.
- Characteristics of a Wedge With Various Holder Configurations for Static-Pressure Measurements in Subsonic Gas Streams
- The characteristics of a wedge static-pressure sensing element with various holder configurations were determined and compared with the characteristics of the conventional tube. The probes were tested over a range of Mach number from 0.3 to 0.95 and at various pitch and yaw angles. The investigation showed that the spike-mounted wedge sensing element has a pressure coefficient comparable with the conventional subsonic static-pressure probe and the pressure coefficient of the wedge varied less than that of the conventional probe for corresponding change of yaw angle.
- Jet effects on pressures and drags of bodies
- From Introduction: "The propulsive jet that discharges from the base of a missile body or nacelle may, by interaction with external stream, cause important drag and stability changes. This paper presents some results of recent investigations by the Lewis and Langley laboratories of the jet effect on body end pressures and drag at zero lift."
- Effects of altitude on turbojet engine performance
- From Summary: "Component and over-all performance characteristics of several turbojet engines investigated in the altitude facilities of the NACA Lewis Laboratory during the last several years are summarized to indicate the effects of altitude on turbojet engine performance. Data presented show that failure of turbojet engine performance to generalize for all altitudes can be traced to reductions in compressor efficiency, corrected air flow, and combustion efficiency at altitude. In addition, it is shown that although engines of different design may have equal thrusts at sea level, the thrusts at altitude may vary widely because of differences in compressor performance characteristics from one engine to another."
- The effects at transonic speeds of thickening the trailing edge of a wing with a 4-percent-thick circular-arc airfoil
- Report presenting an investigation of the effects of a systematic variation of trailing-edge thickness of a symmetrical, circular-arc airfoil on the aerodynamic force, moment, base-pressure, and wake fluctuations using the transonic-bump testing technique. Results regarding the effects of a systematic variation of the trailing-edge thickness, investigation of a boattailed trailing edge, and wake fluctuation characteristics are provided.
- An Investigation of the Low-Speed Stability and Control Characteristics of a 1/10-Scale Model of the McDonnell XF3H-1 Airplane: TED No. NACA DE 344
- "At the request of the Bureau of Aeronautics, Navy Department, an investigation of the low-speed, power-off stability and control characteristics of a 1/10-scale model of the McDonnell XF3H-1 airplane has been made in the Langley free-flight tunnel. Flight tests of the model in the clean and in the slats-and-flaps-extended conditions were made over a lift-coefficient range from about 0.5 through the stall. Only low-altitude conditions were simulated and no attempt was made to determine the effect on the stability characteristics of freeing the controls" (p. 1).
- Effects of Propeller-Shank Geometry and Propeller-Spinner-Juncture Configuration on Characteristics of an NACA 1-Series Cowling-Spinner Combination With an Eight-Blade Dual-Rotation Propeller
- Report presenting an investigation at low speed in the low-turbulence tunnel to determine the effects of variations in propeller-shank geometry and propeller-spinner-juncture configuration on the aerodynamic characteristics of an NACA 1-series cowling-spinner combination with an eight-blade dual-rotation propeller. Results regarding internal flow and external flow are provided.
- Division of Load Among the Wing, Fuselage, and Tail of Aircraft
- Report discussing the division of load among the wing, fuselage, and tail for several aircraft configurations at subsonic and supersonic speeds. The load that each component carries at various Mach numbers and angles of attack is described.
- Base pressures measured on several parabolic-arc bodies of revolution in free flight at Mach numbers from 0.8 to 1.4 and at large Reynolds numbers
- Report presenting base pressures measured on several fin-stabilized bodies of parabolic-arc profile in free flight at a range of Mach and Reynolds numbers. The bodies varied in length but had the same afterbody ratios. Results regarding base pressure coefficients, side pressure coefficients, effect of afterbody length, and drag are provided.
- The Use of Two-Dimensional Section Data to Estimate the Low-Speed Wing Lift Coefficient at Which Section Stall First Appears on a Swept Wing
- Report discusses a procedure for estimating the wing lift coefficient for and spanwise location of the first occurrence of section stall on a swept wing. It has been modified from a method used to calculate the same information for unswept wings. The effects of split flaps, leading-edge modifications, and fences are described.
- Experimental Investigation of Forced-Convection Heat-Transfer Characteristics of Lead-Bismuth Eutectic
- The forced-convection heat-transfer characteristics of lead-bismuth eutectic were experimentally investigated. Experimental values of Nusselt number for lead-bismuth fell considerably below predicted values. The addition of a wetting agent did not change the heat transfer characteristics.
- Altitude-Wind-Tunnel Investigation of Performance Characteristics of a J47D Prototype (RX1-1) Turbojet Engine With Fixed-Area Exhaust Nozzle
- Report presenting an investigation to determine the overall performance of a prototype model of the J47D (RX1-1) turbojet engine with a fixed-area exhaust nozzle. Data was obtained for a range of engine speeds, altitudes, and Mach numbers. Results regarding the effect of those variables and generalization in terms of pumping characteristics are provided.
- An Investigation at Transonic Speeds of the Effects of Control Chord and Span on the Control Characteristics of a Tapered Wedge-Type Wing of Aspect Ratio 2.5: Transonic-Bump Method
- Report presenting an investigation to determine the control characteristics of flap-type controls of various chords and spans on an unswept wing with a modified double-wedge section, an aspect ratio of 2.5, and a taper ratio of 0.625.The control chords in the study were 25, 35, and 45 percent of the wing chord, and the control spans were 25, 50, and 75 percent of the wing semispan. The data from the study indicated that the control-parameter values are approximately proportional to control chord or span for the chords tested.
- Experimental Investigation of Effect of Jet Exit Configuration on Thrust and Drag
- Memorandum presenting an investigation of the problem of performance losses occurring when airplanes equipped with afterburner and cooling-air ejector installations are flown with the afterburner inoperative. Two sources of the performance losses occurring under some operation conditions were identified: an overexpansion of the propulsive jet and an internal shock system and the excessive pumping action resulting from the off-design.
- Altitude-performance and Reynolds number investigation of centrifugal-flow-compressor turbojet engine
- From Introduction: "Altitude-chamber and wind-tunnel investigations of the performance of turbojet engines such as those reported in references 1 to 4 have shown that the conventional correction factors fail to generalize the engine performance variables at high altitudes. An investigation was therefore made at the NACA Lewis laboratory to determine the altitude performance of the J33-A-23 turbojet engine and to demonstrate the magnitude of departure of actual altitude performance from that predicted from sea-level performance."