National Advisory Committee for Aeronautics (NACA) - 1,181 Matching Results
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- 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.
- Effects of Components and Various Modifications on the Drag and the Static Stability and Control Characteristics of a 42 Deg Swept-Wing Fighter-Airplane Model at Mach Numbers of 1.60 to 2.50
- Wind tunnel testing of swept wing fighter aircraft model for determining drag and static longitudinal and lateral stability and control characteristics. Results regarding performance, longitudinal stability, lateral stability, and strakes are provided.
- Blowing-type boundary-layer control as applied to the trailing-edge flaps of a 35 degree swept-wing airplane
- A wind-tunnel investigation was made to determine the effects on the aerodynamic characteristics of a 35 degree swept-wing airplane of applying blowing-type boundary-layer control to the trailing-edge flaps. Flight tests of a similar airplane were then conducted to determine the effects of boundary-layer control on the handling qualities and operation of the airplane, particularly during landing and take-off. The wind-tunnel and flight tests indicated that blowing over the flaps produced large increases in flap lift increment, and significant increases in maximum lift. The use of blowing permitted reductions in the landing approach speeds of as much as 12 knots.
- Comparison of Various Heat Exchangers for Liquid-Metal Nuclear Turbojet Over Range of Flight and Operating Conditions
- Memorandum presenting an analysis of a large number of liquid-metal-to-air heat-exchanger cores for the nuclear-powered liquid-metal turbojet cycle to determine which types yield the best overall net thrust per total engine weight. The performances of all exchangers considered were initially evaluated at a median condition. The performance of the best of each of the four types was compared with that of a shell-and-tube exchanger with the air flowing through the tubes, operating at the same condition.
- 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."
- Effect of control trailing-edge thickness or aspect ratio on the oscillating hinge-moment and flutter characteristics of a flap-type control at transonic speeds
- Report presenting free-oscillation tests in the high-speed tunnel to determine the effect of control trailing-edge thickness and control aspect ratio on the dynamic hinge-moment characteristics of a trailing-edge, flap-type control. Tests were made at a range of Mach numbers and a range of oscillation reduced frequency at an angle of attack of 0 degrees. Results regarding damping moments and flutter characteristics and spring moments are provided.
- Effect of Control Trailing-Edge Thickness or Aspect Ratio on the Oscillating Hinge-Moment and Flutter Characteristics of a Flaptype Control at Transonic Speeds
- Control trailing-edge thickness and aspect ratio effect on oscillating hinge-moment and flutter characteristics of flap-type controls. Results regarding damping moments and flutter characteristics and spring moments are provided.
- Ground Simulator Studies of a Small Side-Located Controller in a Power Control System
- Memorandum presenting an investigation to determine the operating characteristics of a small side-located control stick with the use of a ground simulator incorporating a power control system. The simulator or pitch chair was designed to produce the pitching motion associated with the short-period mode of an airplane. The general opinion of all of the pilots operating the pitch chair was that they were favorably impressed with their ability to precisely track with the small side-located controller provided the control-system characteristics were desirable.
- Low-subsonic investigation to determine the chordwise pressure distribution and effectiveness of spoilers on a thin, low-aspect-ratio, unswept, untapered, semispan wing and on the wing with leading and trailing-edge flaps
- Report presenting an investigation in the 300 mph 7- by 10-foot tunnel to determine the effect of spoilers on the static longitudinal and lateral aerodynamic characteristics and the chordwise pressure distribution on a thin, untapered, unswept, semispan wing with an aspect ratio of 3.33 and NACA 65A004 airfoil sections. Results are presented in the form of static longitudinal and lateral aerodynamic characteristics and tabulated pressure coefficients, section normal-force coefficients, and section pitching-moment coefficients.
- Combustion of gaseous hydrogen at low pressures in a 35 degree sector of a 28-inch-diameter ramjet combustor
- Report presenting testing of gaseous hydrogen fuel burned in a connected-pipe combustor with a cross section equal to 35 degrees sector of a 28-inch diameter. Eleven shrouded fuel-injector configurations were used to obtain combustion data at specified high-altitude ramjet combustor conditions. Results regarding shroud air blockage, mixing tabs, higher equivalence-ratio burning, injector size, flameholder durability, burner length, combustion efficiency, and temperature profile are provided.
- 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.
- Free-Flight Investigation to Determine the Inlet External Drag of Four Inlet Models at Mach Numbers From 1.50 to 3.00
- Memorandum presenting a free-flight investigation conducted on four supersonic nose inlets. Each inlet used conical-shock and isentropic-compression center bodies; two of the models had internal contraction and two did not. Results regarding drag coefficient, pressure recovery, mass-flow ratio, and Reynolds number range are provided.
- Compatibility of Metals with Liquid Fluorine at High Pressures and Flow Velocities
- Report presenting testing of specimens of various metals in selected geometric configurations exposed to liquid fluorine under controlled conditions of flow and pressure. None of the samples eroded, decomposed, or exhibited any measurable physical or chemical changes.
- Incipient spin characteristics of a 1/25-scale model of the Chance Vought XF8U-1 airplane: TED No. NACA AD 3118
- Report presenting an investigation of the incipient spin characteristics of a 1/25-scale dynamic model of the Chance Vought XF8U-1 airplane. The model was launched by a catapult apparatus into free flight at the angle of attack and airspeed correspond to stall with various control settings and was loaded as lightly as possible because of the limitations of the catapult apparatus. Results regarding the basic data and effects of modifications are provided.
- Effects of nose and afterbody modifications on aerodynamic characteristics of a body with and without a vertical tail at a Mach number of 2.01
- Report presenting the effects at Mach number 2.01 of various changes in nose and afterbody shape on the static aerodynamic characteristics of a body of revolution with a fineness ratio of 11 with an ogive nose, a cylindrical center section, and a boattail or cylindrical afterbody. Some body conditions were tested in combination with a vertical tail. Results regarding the effects of nose and afterbody modifications and vertical tail-on configurations are provided.
- Effects of shock-boundary-layer interaction on the performance of a long and a short subsonic annular diffuser
- Report presenting an investigation to determine the effects on performance of positioning normal shocks in or upstream of both a long and a short subsonic annular diffuser. Results regarding the entrance flow conditions, performance for subsonic-entrance flows, and performance with choked- and supersonic-entrance flows are provided.
- An Exploratory Investigation at Mach Numbers of 2.50 and 2.87 of a Canard Bomber-Type Configuration Designed for Supersonic Cruise Flight
- Report presenting results for a canard bomber-type configuration designed for supersonic cruise flight at Mach numbers 2.50 and 2.87 and over a range of angles of attack and angles of sideslip. Results regarding longitudinal characteristics and lateral stability are provided. The original configuration was directionally unstable at low angles of attack, but satisfactory directional stability could be obtained using upper-surface vertical fins.
- Jet effects on the base drag of a cylindrical afterbody with extended nozzles
- A wind-tunnel investigation to determine the effects of both single and twin jets on base drag of a cylindrical body has been conducted at Mach numbers from 0.6 to 1.4. The plane of the jet exit was varied with respect to that of the afterbody. Jet total-pressure ratio ranged up to 20. Significant improvements in base drag were obtained by extending the plane of the jet exits beyond the afterbody base and by venting the base cavity to the external stream.
- Preliminary Transonic Flutter Investigation of Models of T-Tail of Blackburn NA-39 Airplane
- Memorandum presenting a transonic flutter investigation of models of the T-tail of the Blackburn NA-39 airplane. The investigation is to be considered preliminary in that only estimated airplane properties were available for the scaling. Results regarding interpretation of results, presentation of data, and a discussions are provided.
- Preliminary Transonic Flutter Investigation of Models of T-Tall of Blackburn NA-39 Airplane
- Report discussing a transonic flutter investigation of models of the T-tail of the Blackburn NA-39 airplane. The investigation was made at a variety of Mach numbers at simulated altitudes extending to below sea level. The Mach numbers at which asymmetric flutter and symmetric oscillations occur are presented.
- Transonic Flutter Investigation of Models of the Sweptback Wing of a Fighter Airplane
- Memorandum presenting a transonic flutter investigation of models of the wing of a current fighter airplane. The models were dynamically and elastically scaled in accordance with criteria which include a flutter safety margin. Results regarding the presentation of data, interpretation of results, wings without leading-edge chord-extensions, and wings with leading-edge chord-extensions are provided.
- Transonic Flutter Investigation of Models of the Sweptback Wing of a Fighter Airplane
- Report presenting a transonic flutter investigation of models of the wing of a fighter airplane. Results regarding the wings with and without leading-edge chord-extensions, and scaling of the stiffness are presented. The flutter boundary was found to remain below sea level with or without the leading-edge extensions.
- Preliminary Analysis of a Nuclear Powered Supersonic Airplane Using Ramjet Engines
- Report discussing performance estimates for several airplanes using General Electric AC-210 ramjet nuclear-powered engines. Assumptions used for designing the engines, radiation shield, and airframe are described. Potential tradeoffs in regards to power and weight reduction are also discussed.
- Preliminary Analysis of a Nuclear-Powered Supersonic Airplane Using Ramjet Engines
- Report presenting performance estimates for a family of airplanes designed to cruise at Mach number 4.25 and using General Electric AC-210 ramjet engines. The airplane was designed to carry a payload of 10,000 pounds and use a crew of one. Results regarding the shield weight, engine weight, number of engines, and nozzle-velocity coefficient are provided.
- 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."
- 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.
- 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 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.)"
- An Approximate Method for Design or Analysis of Two-Dimensional Subsonic-Flow Passages
- Note presenting a method for the design and analysis of two-dimensional subsonic-flow passages with isentropic nonviscous flow. The method is based on the relation between the pressure change across a stream tube and the centrifugal force resulting from the curvature of the flow. In an example, the method was applied to the design of an expanding elbow at each of two Mach numbers.
- Central Automatic Data Processing System
- A series of papers describing a system that will automatically record as many as 300 pressures, 200 voltages, and 24 frequencies in as little as 30 seconds to an accuracy of 0.15 percent or better of full-scale range. The information is able to be used in any high-speed, general-purpose digital computer. The computer will accept the encoded data produced by the recording system and automatically calibrates it, takes averages, forms ratios, and does terminal calculations such as mass flow, momentum, distortion numbers, drag coefficients, thrust, specific fuel consumption, and efficiency.
- Composition and thermodynamic properties of air in chemical equilibrium
- "Charts have been prepared relating the thermodynamic properties of air in chemical equilibrium for temperatures to 15,000 degrees k and for pressures 10(-5) to 10 (plus 4) atmospheres. Also included are charts showing the composition of air, the isentropic exponent, and the speed of sound. These charts are based on thermodynamic data calculated by the National Bureau of Standards" (p. 1).
- Dilution of liquid oxygen when nitrogen is used for pressurization
- Report presenting a graphic method for determining the composition and phases within a propellant tank when liquid oxygen is pressurized with nitrogen gas and some of the calculations involved. The assumed limiting conditions are that pressurizing gas flows adiabatically from the pressure tank and that equilibrium exists in the oxygen-nitrogen system. The experiment indicates that a series dilution of the oxidant occurs when nitrogen is used as a pressurizing gas, but a barrier at the liquid-gas interface would permit the use of nitrogen.
- Discharge coefficients for combustor-liner air-entry holes 2: flush rectangular holes, step louvers, and scoops
- Experimental discharge coefficients for various types of combustor-liner air-entry holes are presented as a function of a dimensionless flow parameter. In general, scoops and step louvers have higher discharge coefficients and wider flow ranges than flush holes. The effects of size or shape of a given type of hole are small. The proximity of multiple flush holes or the wall inclination of a convergent duct has a negligible effect on discharge coefficient.
- Effect of prior air force over temperature operation on life of J47 buckets evaluated in a sea-level cyclic engine test
- Report presenting an evaluation of buckets of S-816 alloy removed from two J47 engines overtemperatured in service operation. Engine results indicated that the overtemperatured buckets did not fracture in abnormally short operating times. Cracking, particularly on the leading edge, was the principal mode of failure of the buckets.
- Effects of fixing boundary-layer transition for an unswept-wing model and an evaluation of porous tunnel-wall interference for Mach numbers from 0.60 to 1.40
- Report presenting an investigation in the 2- by 2-foot transonic wind tunnel to determine the aerodynamic effects of fixing boundary-layer transition in a forward location on two unswept-wing models differing only in size and with unswept wings of aspect ratio 3.09 with sharp leading edges. Results regarding effects of fixing transition and wall effects in the Ames 2- by 2-foot transonic wind tunnel for an unswept-wing-body model are provided.
- Effects of Mach Number and Wall-Temperature Ratio on Turbulent Heat Transfer at Mach Numbers From 3 to 5
- Note presenting heat-transfer data evaluated from temperature time histories on a cooled cylindrical model with a cone-shaped nose and with turbulent flow at Mach numbers 3.00, 3.44, 4.08, 4.56, and 5.04. The experimental data were compared with calculated values using a modified Reynolds analogy between skin friction and heat transfer. Results regarding the air flow and temperature-distribution results and heat-transfer results are provided.
- Experimental investigation of the drag of flat plates and cylinders in the slipstream of a hovering rotor
- Report presenting an experimental study of the drag of flat plates and cylinders in the slipstream of a hovering rotor. The dynamic pressure profile of the slipstream for stations close to the rotor was characterized by low or slightly negative values in the center, a rise to a peak near the edge of the slipstream, and a rapid decrease to small negative values farther from the center. Results regarding the drag-to-thrust ratio, ratio of percent thrust loss to percent blocked area, and drag coefficients are provided.
- Experimental study of the equivalence of transonic flow about slender cone-cylinders of circular and elliptic cross section
- Report presenting an experimental investigation of the equivalence relationship and the related theory for lifting forces proposed by transonic slender-body theory. Two different models with different dimensions are tested over a range of Mach numbers. Results regarding flow equivalence at sonic speed, Mach number range of equivalence, and lifting pressures at transonic speeds are provided.
- Extreme Speeds and Thermodynamic States in Supersonic Flight
- "The increasing importance of high-speed flow leads to similar problems in various fields of research which are summarized in what follows. Typical of all cases is the conversion of high kinetic energy into extreme thermodynamic states with temperatures of several thousand degrees, frequently connected with dissociation and ionization of the gas involved. There is also a characteristic small sensitivity to the processes discussed in the case of gases of low molecular weight (light gases)" (p. 1).
- A Flight Evaluation and Analysis of the Effect of Icing Conditions on the ZPG-2 Airship
- "A series of test flights was conducted by the U. S. Navy over a 3- year period to evaluate the effects of icing on the operation of the ZPG-2 airship. In supercooled. clouds, ice formed only on the forward edges of small protuberances and wires and presented no serious hazard to operation. Ice accretions of the glaze type which occurred in conditions described as freezing drizzle adversely affected various components to a somewhat greater extent" (p. 1).
- Free Convection Under the Conditions of the Internal Problem
- Convection is called free is the stresses (including the normal pressure) to which the fluid is subjected at its boundaries do not perform mechanical work, that is, if all the boundaries of the fluid are stationary. The case where this is not true is termed forced convection. It corresponds to the action on the fluid of some mechanical suction pumping the fluid.
- Ground reflection of jet noise
- Report presenting the effect of a reflecting plane on the propagation of jet noise investigated theoretically and experimentally. The primary focus of the study is to determine the free-field spectrum of subsonic-jet noise from measurements made in the presence of a ground plane.
- Maximum theoretical tangential velocity component possible from straight-back converging and converging-diverging stators at supercritical pressure ratios
- Report presenting an investigation of the maximum theoretical tangential velocity component possible by expansion about straight-back stator blade trailing edges made by the method of characteristics for converging and converging-diverging stators. Results regarding an approximate method of determining maximum stator exit whirl and comparison of approximate method with method of characteristics are provided.
- Observations of turbulent-burst geometry and growth in supersonic flow
- Report presenting a study of the shape, growth, and formation rate of turbulent bursts in supersonic boundary layers using spark shadowgraphs of small gun-launched models in free flight through still air. The model shapes include cones, ogive-cylinders, and hollow cylinders aligned with the stream. Results regarding the burst thickness profiles, burst plan form and transverse growth, three-dimensional burst shape, burst upstream-edge velocity, burst longitudinal growth rate, burst downstream-edge velocity, burst formation rate, and observations from the shadowgraphs are provided.
- Relation of Journal Bearing Performance to Minimum Oil-Film Thickness
- Note presenting the minimum thickness of the oil film as used as a basic variable in performance curves of plain journal bearings under steady load. The load capacity and the predicted film thickness at the hook point of the friction curves are shown to correlate with the peak-to-valley values of surface roughness when misalignment is absent.
- Stability of Cylindrical and Conical Shells of Circular Cross Section, with Simultaneous Action of Axial Compression and External Normal Pressure
- "We consider in this report the determination of the upper limit of critical loads in the case of simultaneous action of a compressive force, uniformly distributed over plane cross sections, and of isotropic external normal pressure on cylindrical or conical shells of circular cross section. As a starting point we use the differential equations for neutral equilibrium of conical shells which have been used for the solution of the problem of stability of conical shells under torsion and under axial compression; upon solution of the problem it is possible to satisfy all boundary conditions, in contrast to the report where no attention is paid to the fulfillment of the boundary conditions, and to the report where only part of the boundary conditions are satisfied by solution of the problem according to Galerkin's method" (p. 1).
- Stagnation-point heat transfer to blunt shapes in hypersonic flight, including effects of yaw
- An approximate theory is developed for predicting the rate of heat transfer to the stagnation region of blunt bodies in hypersonic flight. Attention is focused on the case where wall temperature is small compared to stagnation temperature. The theoretical heat-transfer rate at the stagnation point of a hemispherical body is found to agree with available experimental data. The effect of yaw on heat transfer to a cylindrical stagnation region is treated at some length, and it is predicted that large yaw should cause sizable reductions in heat-transfer rate.
- Survey of Supersonic Inlets for High Mach Number Applications
- Report discussing various inlet design philosophies based on the results of testing at Mach numbers up to 5. The most ideal inlet design was found to be one with combined external-plus-internal compression due to problems noted with both external-only and internal-only inlets.
- Survey of supersonic inlets for high Mach number applications
- Report presenting an assessment of various inlet design philosophies assessed on the basis of recent experimental results at Mach numbers up to 5. The basic compression systems are compared for Mach 4.0 turbojet and hypersonic-cruise ramjet engines.The best-suited inlet for the Mach 4.0 turbojet engine is the combined external-plus-internal compression.