Technical Report Archive & Image Library (TRAIL) - 1,263 Matching Results
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- An analysis of the fatigue life of an airplane wing structure under overload conditions
- From Introduction: "Fatigue life expectancy in normal transport operations was investigated in reference 1 and was found to be of equal importance with single-gust life. The effect of overload operation of transport airplanes on the probability of encountering single critical gusts was investigated in reference 2 and the frequency of critical gusts was found to increase rapidly with overload. The effect of overload operation on fatigue strength, however, has not heretofore been evaluated, hence the investigations of references 1 and 2 are combined herein to permit such evaluation and to determine the relative importance of fatigue and single-gust failures under conditions of overload operation."
- An analysis of the indications of the University of Chicago airborne turbulence indicator in gusty air
- From Introduction: "The present report has been prepared to discuss the indications obtained from the University of Chicago turbulence indicator in relation to simultaneous measurement of atmospheric gustiness made by the NACA, which are summarized herein."
- An analysis of the skipping characteristics of some full-size flying boats
- From Introduction: "The purpose of this report is to gather together in one place information on the skipping characteristics of number of flying boats. A graph showing the influence of the hull form on the skipping characteristics is given which should be useful in laying out the proportions of the hull in preliminary design to insure good landing behavior."
- Analysis of V-G Records from the SNB-1 Airplane
- Availability data obtained on SNB-1 trainer-class airplanes were analyzed and results presented as flight envelopes which predict occurrences of large values of air speed and acceleration. Comparison is made with SNJ-4 trainer-class airplane data analyzed by the same method. It is concluded that flight envelopes are satisfactory; that the two types show large differences in flight loads and speeds experience; and that SNB-1 will seldom, if ever, exceed design limit load factor and restricted speed, which SNJ-4 can be expected to exceed design-limit load factor and restricted speed in a very small number of flight hours.
- Analysis of V-G Records From the SNJ-4 Airplane
- Report discusses an attempt to adapt a method of analysis of V-G data to predict the occurrences of large values of airspeed and acceleration from an SNJ-4 airplane; the data are presented as "flight envelopes". The flight envelopes "predict that, on average, in a stated number of flight hours, one airspeed, one positive acceleration, and one negative acceleration will exceed the envelope with equal probability of the accelerations being experienced at any airspeed" (from Discussion). The analysis method shows promise for predicting flight loads and speeds for airplanes on which loads due to maneuvers predominate.
- Analysis of Vertical-Tail Loads in Rolling Pull-Out Maneuvers
- Bulletin presenting an analysis of the vertical-tail loads to be expected as a result of abrupt aileron action in accelerated flight, as in rolls from turns or pull-outs, for example. Critical tail loads may occur in rolling pull-out maneuvers, particularly on airplanes with good ailerons and low directional stability.
- Analysis of Wind-Tunnel Stability and Control Tests in Terms of Flying Qualities in Full-Scale Airplanes
- From Summary: "The analysis of results of wind-tunnel stability and control tests of powered airplane models in terms of the flying qualities of full-scale airplanes is advocated. In order to indicate the topics upon which comments are considered desirable in the report of a wind-tunnel stability and control investigation and to demonstrate the nature of the suggested analysis, the present NACA flying-qualities requirements are discussed in relation to wind-tunnel tests. General procedures for the estimation of flying qualities from wind-tunnel tests are outlined."
- An Analytical Investigation of the Effects of Elevator-Fabric Distortion on the Longitudinal Stability and Control of an Airplane
- From Summary: "The results of an analytical investigation to determine the qualitative effects of elevator-fabric distortion on the stick-force characteristics of an airplane are presented. These results indicate that serious alteration of intended stick-force characteristics can be produced by elevator-fabric distortion."
- Analytical investigation of the stability of an F8F dropping model with automatic stabilization
- From Introduction: "All results are presented in the form of motions following abrupt displacements of fixed magnitude - 20^o in bank and 15^o in pitch and yaw - from the reference attitude."
- An analytical investigation of thermal-electric means of preventing ice formations on a propeller blade
- From Introduction: "Flight tests with electricity heated propeller-blade shoes reported in references 1 and 2 have establish the practicability of protecting propeller blades from ice formations by thermal-electric means."
- An analytical study of wing and tail loads associated with an elevator deflection
- From Introduction: "The present paper covers step 1 of the outlined investigation, includes methods of computing the variation of wing and tail loads, and gives numerical results of the application of the theory to the BT-9B airplane. Finally, theoretical formulas are developed and charts are given for computing the maximum increments of wing load, the down-tail load, and the up-tail load following a given elevator displacement."
- Antiknock Effectiveness of Xylidines in Small-Scale Engines
- "The data presented in this report are part of a general program to determine the effects of xylidines on the knock-limited performance of currently used aviation fuels" (p. 2).
- Application of a numerical procedure to stress analysis of stringer-reinforced panels
- From Introduction: "In the present paper a numerical procedure for the stress analysis of flat-sheet and stringer combinations of arbitrary construction and loading is presented and applied to axially loaded panels and to the reinforced covers of box beams."
- Application of Balancing Tabs to Ailerons
- Analysis was made to determine characteristics required of a balancing-tab system for ailerons in order to reduce aileron stick forces to any desired magnitude. Series of calculations based on section data were made to determine balancing-tab systems of various chord tabs and ailerons that will give, for a particular airplane, zero rate of aileron hinge moment with aileron deflection and yet will produce same maximum rate of roll as a plain unbalanced 15-percent chord aileron of same span. Effects of rolling velocity and of forces in tab link on aileron hinge moments have been included.
- The application of data on strength under repeated stresses to the design of aircraft
- From Summary: "This report suggests a method whereby information on the strength under repeated stresses of aircraft materials or structural parts can be used in conjunction with information on service loadings as a means of comparing alternative designs."
- Application of Spring Tabs to Elevator Controls
- Report presenting equations for calculating the stick-force characteristics obtained with a spring-tab type of elevator control. The main problems encountered in the design of the satisfactory elevator spring tab are to provide stick forces in the desired range, to maintain the force per g sufficiently constant throughout the speed range, to avoid undesirable "feel" of the control in ground handling, and to prevent flutter.
- Application of the method of least squares to engine-cooling analysis
- From Introduction: "The purpose of this report is to show that it is practical to apply a least-squares method to the correlation of engine-cooling data."
- An Approximate Determination of the Power Required to Move Control Surfaces as Related to Control-Booster Design
- "As a part of a general investigation of control boosters, preliminary calculations were made to indicate the sizes of control boosters necessary to move the controls of airplanes of various sizes. The analysis was based on the assumption that the controls were moved with a rapidity and amplitude equal to that measured with a fighter airplane in simulated combat. A corollary purpose consisted in determining the effect on reducing booster-power unit size of incorporating an energy accumulator in the booster system" (p. 1).
- Approximate Formulas for the Computation of Turbulent Boundary-Layer Momentum Thicknesses in Compressible Flows
- Report presenting approximate formulas for the computation of the momentum thickness of turbulent boundary layers on two-dimensional bodies, on bodies of revolution at zero angle of attack, and on the inner surfaces of round channels all in compressible flow given in the form of integrals that can be conveniently computed. Results for skin-friction formulas, laminar boundary layers, and full thickness of boundary layer are provided.
- An Approximate Method of Shear-Lag Analysis for Beams Loaded at Right Angles to the Plane of Symmetry of the Cross Section
- Report discussing strain measurements made on a box beam of triangular cross section and on two beams of D-section under transverse bending. Information about the arrangement of the beams and experimental and calculated stresses for different boxes.
- Artificial Running-in of Piston Rings
- Report presenting a consideration of the performance of sliding surfaces, such as piston rings, cylinders, journals, and bearings in aircraft engines with reference to the surface characteristics that they possess before and after running-in, prior to service operation. The phenomena accompanying the running-in process are analyzed.
- Attainment of a Straight-Line Trajectory for a Preset Guided Missile With Special Reference to Effect of Wind or Target Motion
- Report discusses the results of a study "of the requirements for the attainment of a straight-line trajectory for a preset guided missile in the presence of wind or target motion" (from Summary). Information about the straight-line trajectory, position of the launching airplane, straight-line collision course, and arrangement of the autopilot in the missile is provided. Recommendations are also made about the creation of a bombsight mounting for the pilot of the launching airplane in order to attain the desired straight-line collision course.
- An Automatically Variable Control Linkage and Its Effect on the Lateral-Control Characteristics of a High-Speed Fighter Airplane
- Report discusses an analysis and preliminary design of a control linkage that varies automatically with dynamic pressure. The advantages of the device, including greater lateral control than a fixed control linkage without additional aerodynamic balance, are detailed. The effect of variable linkage on lateral-control characteristics is also described.
- The belt method for measuring pressure distribution
- "The measurement of pressure distribution may be accomplished rapidly for any number of locations deemed necessary in model or full-scale investigations by use of the 'belt' method. Reasonable accuracy may be obtained by careful use of this method" (p. 1).
- Bending and Shear Stresses Developed by the Instantaneous Arrest of the Root of a Cantilever Beam Rotating With Constant Angular Velocity About a Transverse Axis Through the Root
- From Summary: "A theoretical investigation was made of the behavior of a cantilever beam in rotational motion about a transverse axis through the root determining the stresses, the deflections, and the accelerations that occur in the beam as a result of the arrest of motion. The equations for bending and shear stress reveal that, at a given percentage of the distance from root to tip and at a given trip velocity, the bending stresses for a particular mode are independent of the length of the beam and the shear stresses vary inversely with the length. When examined with respect to a given angular velocity instead of a given tip velocity, the equations reveal that the bending stress is proportional to the length of the beam whereas the shear stress is independent of the length."
- Bending and Shear Stresses Developed by the Instantaneous Arrest of the Root of a Cantilever Beam With a Mass at Its Tip
- Report discusses an investigation into the behavior of a cantilever beam in transverse motion with a mass at its tip when the root is suddenly brought to rest. Equations for determining the stresses, deflections, and accelerations that arise in the beam are also provided. This testing can be applied to the shock created in an airplane when landing and the vibrations that result.
- Bending and Shear Stresses Developed by the Instantaneous Arrest of the Root of a Moving Cantilever Beam
- Report presenting a theoretical and experimental investigation of the behavior of a cantilever beam in transverse motion when its root is suddenly brought to rest. The results of both types of investigations are compared.
- Bibliography and Review of Information Relating to the Hydrodynamics of Seaplanes
- Report presenting a bibliography and review of information related to the hydrodynamics of seaplanes. Characteristics of conventional hulls and floats are discussed to show the effects upon performance of changes in design parameters like dead rise, depth of step, and angle of afterbody keel. Other topics include floats, lateral stabilizers, aerodynamic and propulsive considerations, unconventional configurations, hydrofoils, and piloting and handling.
- Blade Design Data for Axial-Flow Fans and Compressors
- Report presenting an investigation to obtain blade design data for high-efficiency axial-flow fans and compressors, which were carried out in a two-dimensional low-speed cascade tunnel. The effects of camber, solidity, and stagger on blade turning angle and the shape of pressure distributions were determined for a family of five low-drag airfoils.
- Boundary-Layer Transition on the N.A.C.A. 0012 and 23012 Airfoils in the 8-Foot High-Speed Wind Tunnel
- Report presenting determinations of boundary-layer transition on the NACA 0012 and 23012 airfoils in the high-speed wind tunnel over a range of Reynolds numbers. For all of the lift coefficients that testing occurred at, transition occurred in the region of estimated laminar separation at low Reynolds numbers and approached the point of minimum static pressure as a forward limit at high Reynolds numbers.
- Breaking Aircraft-Engine Oil Foams by Use of Electrically Charged Condenser Plates
- Report presenting a determination of the effectiveness of a charged condenser for breaking oil foams and to obtain data on which to base the design of such a device for mounting at the oil-tank inlet of an airplane. Results regarding the condenser-plate area and arrangement, wet-plate design, condenser voltage, oil temperature, water in oil, and some safety considerations are provided.
- Calculated and measured turning performance of a Navy F2A-3 airplane as affected by the use of flaps
- Report presenting results of flight tests to determine the turning performance of a Navy F2A-3 airplane over a range of speeds for three flap deflections at two altitudes. The results are correlated with an analytical study of turning performance in which the effect of thrust on maximum lift coefficient was considered.
- Calculated effects of full-span slotted and Fowler flaps on longitudinal stability and control characteristics for a typical fighter-type airplane with various tail modifications
- Report presenting an analytical study of the influence of full-span slotted and Fowler flaps on the requirements for horizontal tail surfaces. The elevator deflection required to land at three-point attitude, elevator deflection required to stall the airplane at altitude, and permissible center-of-gravity range have been calculated for a fighter-type airplane.
- Calculation of Stick Forces for an Elevator With a Spring Tab
- "Formulas for the calculation of hinge-moment characteristics of an elevator with a spring tab have been developed in terms of basic aerodynamic parameters, spring stiffness, and airspeed. The formulas have been used in a study of the stick-force gradients on a pursuit airplane equipped with an elevator with a spring tab. Charts are presented showing the variation of stick-force gradient in accelerated flight over a large range of speed and the complete range of spring stiffness for various center-of-gravity locations, altitudes, and airplane sizes" (p. 1).
- Calculation of tab characteristics for flight conditions from wind-tunnel data
- Report presenting tail-surface characteristics calculated from wind-tunnel data, which have been reported to not correspond with flight-test measurements. The primary problem under consideration is the calculation of the effect of tab deflection on the free-floating angle of the elevator, as in a servocontrol.
- Calculation of the Aileron and Elevator Stick Forces and Rudder Pedal Forces for the Bell XP-83 Airplane (Project MX-511) in Spins
- "Aileron and elevator stick forces and rudder pedal forces for the Bell XP-83 airplane in spins have been calculated. The results indicate that the aileron and elevator stick forces may be excessive unless some suitable booster or more highly balanced control surfaces are used. The pilot will be able to move the surfaces only slightly from their normal floating locations" (p. 1).
- Calculations of Intake-Air Cooling Resulting From Water Injection and of Water Recovery From Exhaust Gas
- Report discussing some calculations made for the effects of water in cooling the inlet air of aircraft-engine cylinders. From Summary: "The estimates indicate that the cooling effect of the water on the inlet air can be more extensive than the cooling now obtained with the intercoolers or aftercoolers in the air-induction system. In connection with water recovery from the exhaust gas, the estimates indicate that sufficient water can be recovered from 50 percent of the exhaust gas to provide an inducted water-fuel ratio of 0.5."
- Calculations of the Performance of a Compression-Ignition Engine-Compressor Turbine Combination 1: Performance of a Highly Supercharged Compression-Ignition Engine
- From Summary: "Small high-speed single-cylinder compression-ignition engines were tested to determine their performance characteristics under high supercharging. Calculations were made on the energy available in the exhaust gas of the compression-ignition engines. The maximum power at any given maximum cylinder pressure was obtained when the compression pressure was equal to the maximum cylinder pressure. Constant-pressure combustion was found possible at an engine speed of 2200 rpm."
- Calibration of Three Temperature Probes and a Pressure Probe at High Speeds
- "Three Franz-type temperature probes and a pitot-static tube for use in supercharger passages have been calibrated in the NACA 24-inch high-speed wind tunnel. These instruments were designed for use in supercharger investigations" (p. 1).
- Calibrations of pitot-static tubes at high speeds
- Report presenting the calibrations of three types of service pitot-static tubes over an approximate range of speeds of 150 to 600 miles per hour. The calibrations indicated a need for a pitot-static tube with greater accuracy, especially at higher speeds. Results regarding the service tubes, Prandtl tube, Eigh-speed tube, and a comparison of the tubes are provided.
- Calibrations of Service Pitot Tubes in the Langley 24-Inch High-Speed Tunnel
- Report discusses calibration testing performed on a Kollsman type G-1 and an NAF No. 1 pitot tube at several Mach numbers and angles of attack. The effect of drain holes on the flow within the pitot tube was analyzed and the ability to estimate the error in the total pressure was created. The accuracy of the extrapolated and estimated values were found to be within reasonable limits.
- Cascade investigation of buckets for a modern aircraft turbosupercharger
- Report presenting a cascade investigation in two-dimensional flow in the 5-inch cascade tunnel and the 1-inch turbine-element testing apparatus to obtain a satisfactory bucket design for use in a modern aircraft turbosupercharger. Results regarding the root sections, pitch sections, and tip sections are provided.
- Characteristics of an NACA 66, S-209 section hydrofoil at several depths
- Report presenting an investigation of the force characteristics of single hydrofoils in order to help with preliminary hydrofoil design.
- Characteristics of beveled-trailing-edge elevators on a typical pursuit fuselage at altitudes simulating-normal flight and spin conditions
- Report presenting lift and elevator hinge-moment characteristics were measured on horizontal tail provided with elevators having three different beveled trailing edges. Results regarding fuselage alone and fuselage interference, lift characteristics of fuselage-tail combination, elevator hinge-moment characteristics, drag, and comparison with data from two-dimensional-flow tests are provided.
- Characteristics of Naca 4400R Series Rectangular and Tapered Airfoils, Including the Effect of Split Flaps
- "At the request of the Bureau of Aeronautics, Navy Department, tests were made in the variable-density wind tunnel of a tapered wing of 3-10-18 plan form and based on the NACA 4400R series sections. The wing was also tested with 0.2 chord split flaps, deflected 60 degrees, in the center of the wing and having flat span to wing span ratios of 0.3, 0.5, 0.7, and 1.0, respectively" (p. 1).
- Characteristics of plain and balanced elevators on a typical pursuit fuselage at attitudes simulating normal-flight and spin conditions
- Report presenting lift and elevator hinge-moment characteristics of a horizontal tail with various plain and balanced elevators and mounted on a typical pursuit fuselage as measured in the 7- by 10-foot wind tunnel at attitudes simulating normal-flight and spin conditions. The lift effectiveness of the elevator was practically independent of the size of the aerodynamic balance. Results regarding the fuselage alone and fuselage interference, lift characteristics of fuselage-tail combinations, lift effectiveness of the tab, elevator hinge moments, parameters, effect of yaw on elevator hinge moments, effect of tab on elevator hinge moments, drag, and comparison with two-dimensional data are provided.
- Characteristics of Several Single- and Dual-Rotating Propellers in Negative Thrust
- Report discusses the thrust and power characteristics of several single- and dual-rotating propellers with differing blade width and number of blades for negative-thrust operation from -45 degrees to 145 degrees blade angle. From Summary: "The tests indicate that it is possible to predict for a given propeller design characteristics in the negative-thrust range from known characteristics at a different activity factor. Adequate negative thrusts were indicated for extremely high positive as well as negative blade angles."
- Characteristics of the BMW 801D2 Automatic Engine Control as Determined From Bench Tests
- Report discusses the results of bench testing on a German BMW 301D2 to determine the relation between the control parameters and any special methods by which the control principles are adapted to the control of the engine. Characteristics are presented for a variety of simulated manifold pressures, charge-air temperatures, engine speeds, and altitudes. Special attention is paid to the pressure characteristics of the servo-oil system and the potential effects of its failure on the operation of the automatic engine-control system.
- The Characteristics of Two Model Six-Blade Counterrotating Pusher Propellers of Conventional and Improved Aerodynamic Design
- Two airfoil plans were used for propeller blades. One is modified Clark Y section designed for structural reliability and the second an NACA 16 airfoil section designed to produce minimum aerodynamic losses. At low air speeds, the propeller designed for aerodynamic effects showed a gain of from 1.5 to 4.0 percent in propulsive efficiency over the conventional type depending on the pitch. Because of the numerous variables involved, the effect of each one on the aerodynamic characteristics of the propellers could not be isolated.
- Charts for Calculation of the Critical Compressive Stress for Local Instability of Idealized Web- and T-Stiffened Panels
- "Charts are presented for the calculation of the critical compressive stress - the stress at which local instability occurs - for idealized web- and T-stiffened panels, and examples of the use of the charts are given" (p. 1).