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Acceleration Measurements During Landing in Rough Water of a 1/7-Scale Dynamic Model of Grumman XJR2F-1 Amphibian - Langley Tank Model 212: TED No. NACA 2378
From Summary: "Tests of a 1/7 size model of the Grumman XJR2F-1 amphibian were made in Langley tank no.1 to examine the landing behavior in rough water and to measure the normal and angular accelerations experienced by the model during these landings. All landings were made normal to the direction of wave advance, a condition assumed to produce the greatest accelerations. Wave heights of 4.4 and 8.0 inches (2.5 and 4.7 ft, full size) were used in the tests and the wave lengths were varied between 10 and 50 feet (70 and 350 ft, full size)."
Aerodynamic characteristics at high speeds of related full-scale propellers having different blade-section cambers
From Summary: "Wind-tunnel tests of a full-scale two-blade NACA 10-(10)(08)-03 (high camber) propeller have been made for a range of blade angles from 20 degrees to 55 degrees at airspeeds up to 500 miles per hour. The results of these tests have been compared with results from previous tests of the NACA 10-(3) (08)-03 (low camber) and NACA 10-(5)(08)-03 (medium camber) propellers to evaluate the effects of blade-section camber on propeller aerodynamic characteristics."
Aerodynamic Characteristics of a 42 Degree Swept-Back Wing With Aspect Ratio 4 and NACA 64(Sub 1)-112 Airfoil Sections at Reynolds Numbers From 1,700,000 to 9,500,000
Report discussing testing on a 42 degree swept-back wing to determine its low-speed aerodynamic characteristics in pitch and yaw at high Reynolds numbers. The main effect of increasing the Reynolds number was delayed wing stalling to higher angles of attack. Roughness on the wing leading edge also had a large adverse effect on lift, drag, and pitching-moment characteristics at higher Reynolds numbers.
Aerodynamic Characteristics of a Portion of the Horizontal Tail from a Douglas C-74 Airplane with Fabric-Covered Elevators
"A Douglas C-74 airplane, during a test dive at about 0.525 Mach number, experienced uncontrollable longitudinal oscillations sufficient to cause shedding of the outer wing panels and the subsequent crash of the airplane. Tests of a section of the horizontal tail plane from a C-74 airplane were conducted in the Ames 16-foot high-speed wind tunnel to investigate the possibility of the tail as a contributing factor to the accident. The results of the investigations of fabric-covered elevators in various conditions of surface deformation are presented in this report" (p. 1).
Aerodynamic Characteristics of Several NACA Airfoil Sections at Seven Reynolds Numbers From 0.7 X 10(Exp 6) to 9.0 X 10(Exp 6)
Report presenting an investigation of the two-dimensional aerodynamic characteristics of several NACA airfoil sections at four Reynolds numbers. Results regarding the minimum drag, maximum lift, lift-curve slope, and angle of zero lift and pitching moment are provided.
Aerodynamic study of a wing-fuselage combination employing a wing swept back 63 degrees: Effects of split flaps, elevons, and leading-edge devices at low speed
Report presenting an investigation to evaluate the effects of split flaps, elevons, sharp leading edges, drooped-nose flaps, and extended-nose flaps on the lift, drag, and pitching-moment characteristics at low speed of a wing-fuselage combination with a wing with the leading edge swept back 63 degrees and an aspect ratio of 3.5. Results regarding the plain wing and wing-fuselage combinations, Reynolds number, split flaps, elevons, leading-edge devices, and highest lift coefficient attained before longitudinal instability are provided.
Aerodynamic study of a wing-fuselage combination employing a wing swept back 63 degrees: Investigation at a Mach number of 1.53 to determine the effects of cambering and twisting the wing for uniform load at a lift coefficient of 0.25
Testing was performed at Mach number 1.53 with a wing-fuselage combination with a wing with 63 degrees leading-edge sweep, an aspect ratio of 3.46, and a taper ratio of 0.25. The wing had an NACA 64A005 thickness distribution parallel to the plane of symmetry and was cambered and twisted. Results regarding the comparison of lift, drag, and pitching-moment characteristics of WF-63c and WF-63, effects of sweep, and effects of Reynolds number are provided.
Altitude-wind-tunnel investigation of AN-F-58 fuel in experimental version of J47 turbojet engine
An altitude-wind-tunnel investigation of the performance of AN-F-58 and AN-F-32 fuels in an experimental turbojet engine was conducted over a range of simulated altitudes and flight Mach numbers. Combustion efficiencies obtained with AN-F-58 and AN-F-32 fuels were approximately equal. The minimum-speed altitude operational limit was essentially the same with either AN-F-58 or AN-F-32 fuel. Starting characteristics of the two fuels were approximately the same at low wind milling speeds. Visual observation showed no apparent differences in the carbon-deposition rates of AN-F-58 and AN-F-32 fuels.
Altitude-wind-tunnel investigation of thrust augmentation of a turbojet engine II: performance with water injection at compressor inlet
Report presenting testing of a standard turbojet engine by water injection at the inlet of the axial-flow compressor in the altitude wind tunnel. Engine performance at 7600 rpm was obtained over a wide range of water-air-pressure ratios and ram-pressure ratios. Results regarding the engine-component performance are also provided.
Analysis of Available Data on Control Surfaces Having Plain-Overhang and Frise Balances
From Introduction: "The present paper deals with control surfaces having plain-overhang and Frise balances."
Analysis of available data on the effectiveness of ailerons without exposed overhang balance
From Introduction: "As a part of the general lateral-control investigation by the NACA, the large amount of two- and three-dimensional data on the rolling effectiveness of ailerons without exposed overhang balance is collected and analyzed in the present paper."
Analysis of Available Data on the Effects of Tabs on Control-Surface Hinge Moments
From Introduction: "A collection balanced-aileron test data is given in reference 1. Reference 2 presents a collection of data applicable to the design of tail surfaces. The results of analyses of data for control surfaces with internal balances, plain-overhang and Frise balances, beveled trailing edges, and unshielded horn balances have already been published in references 3 to 6."
Analysis of Circular Shell-Supported Frames
From Summary: "This paper deals with the single problem if circular shell-supported frames subjected to concentrated loadings. A mathematical attack is developed and presented in the form of nondimensional-coefficient curves."
An analysis of life expectancy of airplane wings in normal cruising flight
From Summary: "In order to provide a basis for judging the relative importance of wing failure by fatigue and by single intense gusts, an analysis of wing life for normal cruising flight was made based on data on the frequency of atmospheric gusts. The independent variables considered in the analysis included stress-concentration factor, stress-load relation, wing loading, design and cruising speeds, design gust velocity, and airplane size. Several methods for estimating fatigue life from gust frequencies are discussed."
An Analysis of the Factors Affecting the State of Fuel and Air Mixtures
From Introduction: "It is the purpose of this paper to describe the physical properties that are necessary to specify mixture quality in a system containing fuel and dry air and to evaluate the theoretical rolation between these properties and the physical properties of the mixture."
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."
Appreciation and determination of the hydrodynamic qualities of seaplanes
Report presenting a summary of the hydrodynamic qualities of interest in the normal operation of a seaplane, established over a period of years by model testing and by some knowledge of full-size operation. Results regarding longitudinal stability and control, landing stability, seaworthiness, performances, and lateral stability and control are provided.
An Approximate Method for Estimating the Incompressible Laminar Boundary-Layer Characteristics on a Flat Plate in Slipping Flow
Memorandum presenting an approximate method for the estimation of the properties of the incompressible laminar boundary layer on a flat plate in the slip-flow region using Karman's momentum method. At equivalent stations, the total thickness and the skin friction of a slipping boundary layer are less than that of the normal boundary layer at the same Reynolds number.
Approximate Relations and Charts for Low-Speed Stability Derivatives of Swept Wings
Contains derivations, based on a simplified theory, of approximate relations for low-speed stability derivatives of swept wings. Method accounts for the effects and, in most cases, taper ratio. Charts, based on the derived relations, are presented for the stability derivatives of untapered swept wings. Calculated values of the derivatives are compared with experimental results.
An automatic electrical analyzer for 45 degree strain-rosette data
Report presenting a device that automatically analyses the data from a 45 degree strain rosette. The rosette strains are properly combined by means of an electric circuit to yield a direct meter reading of maximum shear strain and major and minor principal strains.
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.
Bending of Rectangular Plates with Large Deflections
"The solution of von Karman's fundamental equations for large deflections of plates is presented for the case of a simply supported rectangular plate under combined edge compression and lateral loading. Numerical solutions are given for square plates and for rectangular plates with a width-span ratio of 3:1. The effective widths under edge compression are compared with effective widths according to von Karman, Bengston, Marguerre, and Cox and with experimental results by Ramberg, McPherson, and Levy" (p. 1).
Bending of Rectangular Plates With Large Deflections
"The solution of Von Karman's fundamental equations for large deflections of plates is presented for the case of a simply supported rectangular plate under combined edge compression and lateral loading. Numerical solutions are given for square plates and for rectangular plates with a width-span ratio of 3:1. The effective widths under edge compression are compared with effective widths according to Von Karman, Bengston, Marguerre, and Cox and with experimental results by Ramberg, Mcpherson, and Levy" (p. 1).
Bending Stresses Due to Torsion in a Tapered Box Beam
Note presenting a method for the calculation of bending stresses due to torsion in a tapered box beam. A special taper was assumed in which all flanges, if extended, would meet at a point. The results obtained by this method were compared with experimental data obtained from tests performed on a tapered box beam.
Bending-Torsion Flutter Calculations Modified by Subsonic Compressibility Corrections
Report presenting a number of calculations of bending-torsion wing flutter at two Mach numbers and a comparison of the results. The results indicated that the effect of compressibility on flutter speed for subsonic speeds with no shocks, although complicated, is relatively small in the usual cases.
Biaxial Fatigue Strength of 24S-T Aluminum Alloy
Note presenting an investigation to determine the fatigue-strength values for 24S-T aluminum alloy when subjected to various ratios of biaxial stresses. The stresses considered were both tensile. The results indicated that uniaxial fatigue-strength values in the longitudinal direction cannot be used to predict the fatigue strength, and that biaxial fatigue strength may be as low as 50 percent of the uniaxial fatigue strength.
Biaxial Plastic Stress-Strain Relations for 24S-T Aluminum Alloy
Note presenting an investigation to determine the yield strength, ultimate strength, ductility, and plastic stress-stain relations for 24S-T aluminum alloy when subjected to biaxial stresses. The data were interpreted by a generalized St. Venant theory in an attempt to predict the biaxial stress-strain relations in terms of the uniaxial tensile stress-strain relations. Stress-strain data were also obtained from flat control specimens cut from tubular specimens and compared with tension test data obtained from tubular specimens.
Boundary-Induced Upwash for Yawed and Swept-Back Wings in Closed Circular Wind Tunnels
Report presenting a determination of the tunnel-induced velocities for yawed and swept-back airfoils in a closed circular wind tunnel. Calculations were performed for elemental horseshoe vortices with one tip of the bound vortex on the tunnel axis for a range of yaw angles and bound-vortex lengths.
A Brief Study of the Speed Reduction of Overtaking Airplanes by Means of Air Brakes
"As an aid to airplane designers interested in providing pursuit airplanes with decelerating devices intended to increase the firing time when overtaking another airplane, formulas are given relating the pertinent distances and speeds in horizontal flight to the drag increase required. Charts are given for a representative parasite-drag coefficient from which the drag increase, the time gained, and the closing distance may be found. The charts are made up for three values of the ratio of the final speed of the pursuing airplane to the speed of the pursued airplane and for several values of the ratio of the speed of the pursued airplane to the initial speed of the pursuing airplane" (p. 1).
Buckling Stresses of Clamped Rectangular Flat Plates in Shear
"By consideration of antisymmetrical, as well as symmetrical, buckling configurations, the theoretical shear buckling stresses of clamped rectangular flat plates are evaluated more correctly than in previous work. The results given, which represent the average of upper- and lower-limit solutions obtained b the Lagrangian multiplier method, are within 1 1/4 percen of true buckling stresses" (p. 1).
Calculated condenser performance for a steam turbine power plant for aircraft
Report presenting calculations to determine the effect of several operating conditions on the performance of condensers for steam-turbine power plants. The analysis covered a range of turbine-inlet pressures and turbine-outlet pressures for various condenser cooling-air pressure drops, flight speeds, and altitudes. Results regarding steam-cycle performance, effect of turbine-outlet pressure on condenser performance, effect of cooling-air pressure drop on condenser performance, effect of turbine-inlet temperature on condenser performance, and power-plant-weight estimates are provided.
Calculations of the supersonic wave drag of nonlifting wings with arbitrary sweepback and aspect ratio : wings swept behind the Mach lines
Report presenting calculations of the supersonic wave drag at zero lift for a series of wings with thin symmetrical biconvex sections with untapered plan forms and various angles of sweepback and aspect ratios.
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 Thin Triangular Wings With Triangular-Tip Control Surfaces at Supersonic Speeds With Mach Lines Behind the Leading Edge
Note presenting a theoretical analysis, based on the linearized equation for supersonic flow, of the characteristics of triangular-tip control surfaces on thin triangular wings. The ratio of lift effectiveness to the hinge moment which resulted from control deflection was equal to the corresponding two-dimensional ratio for the same ratio of flap area to wing area.
Charts for rapid analysis of 45 degree strain-rosette data
From Summary: "Charts are presented for rapidly determining the principal strains and stresses, the maximum shear strain and stress, and the orientation of principal axes from data on 45 degree strain rosettes. The charts may be used for analyzing the conventional data consisting of strains measured along three gage lines 45 degrees apart, but their application is more direct if the rosette data are obtained by means of special circuits that require the use of four gages 45 degrees apart."
Charts for stress analysis of reinforced circular cylinders under lateral loads
Report presenting charts with coefficients for the stress analysis of a reinforced circular cylinder. They allow for the rapid determination of sheer flows and direct stresses in the sheet of a cylinder as well as the shear forces, axial forces, and bending moments in the rings. Separate charts are also given for three basic ring loadings.
Charts of Thermodynamic Properties of Fluids Encountered in Calculations of Internal Combustion Engine Cycles
"A single chart has been prepared that simplifies the calculation of the thermodynamic properties of air, various octene-air mixtures, and mixtures of those with their products of combustion at all temperatures below which chemical dissociation becomes unimportant. The chart is based on the use of 1 pound mol of mixture, and examples of its use are given in the form of the calculation of a turbocompressor power plant and a supercharged Otto engine cycle" (p. 1).
Collection and analysis of wind-tunnel data on the characteristics of isolated tail surfaces with and without end plates
Report presenting the aerodynamic characteristics of 19 isolated tail surfaces, which have been determined by wind tunnel tests. Testing was also made of rectangular airfoils of various aspect ratios with and without double end plates of various shapes. The analysis indicated that the slope of the lift curve could be predicted within 10 percent for all models by use of lifting-surface-theory equations.
Column and Plate Compressive Strengths of Aircraft Structural Materials: Extruded 14S-T Aluminum Alloy
"Column and plate compressive strengths of extruded 14S-T aluminum alloy were determined both within and beyond the elastic range from tests of flat-end H-section columns and from local-instability tests of H-, Z-, and channel-section columns. These tests are part of an extensive research investigation to provide data on the structural strength of various aircraft materials. The results are presented in the form of curves and charts that are suitable for use in the design and analysis of aircraft structures" (p. 1).
Column Strength of Aluminum Alloy 14S-T Extruded Shapes and Rod
Note presenting an investigation of the use of aluminum alloy 14S-T in heavy-duty structural applications and aircraft. The column data presented in this report have been obtained on extruded shapes and on rolled and drawn rod of the alloy.
A comparison of analytically and experimentally determined isothermal pressure losses in a heat-exchanger installation
The results of this analysis indicate that isothermal pressure losses can be predicted analytically in the type of ducting system which may be broken down into the elementary forms of elbows, diffusers, and straight ducts for which pressure-loss data are published.
Comparison of Drop and Wind-Tunnel Experiments on Bomb Drag at High Subsonic Speeds
The drag coefficients of bombs at high velocities velocity of fall was 97 percent of the speed of sound) (the highest are determined by drop tests and compared with measurements taken in the DVL high-speed closed wind tunnel and the open jet at AVA - Gottingen.
Comparison of Intercooler Characteristics
"A method is presented of comparing the performance, weight, and general dimensional characteristics of inter-coolers. The performance and dimensional characteristics covered in the comparisons are cooling effectiveness, pressure drops and weight flows of the charge and cooling air, power losses, volume, frontal area, and width. A method of presenting intercooler data is described in which two types of charts are plotted; (1) A performance chart setting forth all the important characteristics of a given intercooler and (2) a replot of these characteristics for a number of intercoolers intended to assist in making a selection to satisfy a given set of installation conditions" (p. 1).
Comparison of measured and calculated stresses in built-up beams
Web stresses and flange stresses were measured in three built-up beams: one of constant depth with flanges of constant cross-section, one linearly tapered in depth with flanges of constant cross section, and one linearly tapered in depth with tapered flanges. The measured stresses were compared with the calculated stresses obtained by the methods outlined in order to determine the degree of accuracy that may be expected from the stress analysis formulas. These comparisons indicated that the average measured stresses for all points in the central section of the beams did not exceed the average calculated stresses by more than 5 percent. It also indicated that the difference between average measured flange stresses and average calculated flange stresses on the net area and a fully effective web did not exceed 6.1 percent.
Comparison of Pitching Moments Obtained During Seaplane Landings With Values Predicted by Hydrodynamic Impact Theory
Report presenting an investigation of pitching moments and center-of-pressure locations obtained from a landing investigation in smooth water of a conventional flying boat as compared to values predicted by general hydrodynamic impact theory. Landings were generally moderate and covered as wide a range of trim and velocities as practical. Results regarding the center of pressure and pitching moments are provided.
Comparison of several methods of predicting the pressure loss at altitude across a baffled aircraft-engine cylinder
Report presenting several methods of predicting the compressible-flow pressure loss across a baffled aircraft-engine cylinder that were analytically and experimentally investigated on a typical air-cooled aircraft-engine cylinder. Results regarding the evaluation of data, comparative accuracy of correction methods, and ability to apply information about heat transfer to compressible-flow pressure-drop predictions are provided.
Comparison of Static Strengths of Machine Countersunk Riveted Joints in 24S-T, X75S-T, and Alclad 75S-T Sheet
Note presenting static tests made on machine-countersunk riveted joints in 24S-T, X75S-T, and Alclad 75S-T sheet using A17S-T and 24S-T rivets. In order to intensify the cutting action of the rivets, all specimens were made with the depth of countersink just equal to the thickness of the sheet.
Comparison of the Knock-Limited Performance of Triptane With 23 Other Purified Hydrocarbons
"The knock-limited performance of blends containing General Motors triptane in S reference fuel and in an S plus M base fuel was determined in 17.6, F-3, F-4, and full-scale (single cylinder) engines. The results obtained are presented and are compared with published data from similar tests of 12 aromatics, 10 paraffins (including highly purified triptane), and 2 olefins. The comparison of fuels - which is based on a consideration of (a) antiknock blending sensitivity, (b) lead susceptibility, (c) temperature sensitivity, and (d) comparison of small-scale and full-scale engine data - is presented by means of bar graphs" (p. 1).
Comparison of Three Exit-Area Control Devices on an N.A.C.A. Cowling, Special Report
"Adjustable cowling flaps, an adjustable-length cowling skirt, and a bottom opening with adjustable flap were tested as means of controlling the rate of cooling-air flow through an air-cooled radial-engine cowling. The devices were tested in the NACA 20-foot tunnel on a model wing-nacelle-propeller combination, through an airspeed range of 20 to 80 miles per hour, and with the propeller blade angle set 23 degrees at 0.75 of the tip radius. The resistance of the engine to air flow through the cowling was simulated by a perforated plate" (p. 1).
Comparison of Two-Dimensional Air Flows About an NACA 0012 Airfoil of 1-Inch Chord at Zero Lift in Open and Closed 3-Inch Jets and Corrections for Jet-Boundary Interference
Note presenting pressure distributions and schileren photographs for the high-speed flow about a symmetrical airfoil at zero lift in open and closed jets in order to show the nature of the jet-boundary interference. Results regarding the application of jet-boundary-interference theory, analysis of experimental wall-interference data and comparison with theory, conditions near choking, and change of velocity ratio with Mach number are provided.
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