National Advisory Committee for Aeronautics (NACA) - 766 Matching Results

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Aerodynamic Characteristics of a Refined Deep-Step Planing-Tail Flying-Boat Hull with Various Forebody and Afterbody Shapes: From Summary: "An investigation was made in the Langley 300 mph 7-by 10-foot tunnel to determine the aerodynamic characteristics of a refined deep-step planing-tail hull with various forebody and afterbody shapes. For comparison, tests were made on a streamline body simulating the fuselage of a modern transport airplane. The results of the tests, which include the interference effects of a 21-percent-thick support wing, indicated that for corresponding configurations the hull models incorporating a forebody with a length-beam ratio of 7 had lower minimum drag coefficients than the hull models incorporating a forebody with a length-beam ratio of 5. Longitudinal and lateral stability was generally about the same for all hull models tested and about the same as that of a conventional hull."
Aerodynamic characteristics of a two-blade NACA 10-(3)(062)-045 propeller and of a two-blade NACA 10-(3)(08)-045 propeller: Report discussing characteristics are given for the two-blade NACA 10-(3)(062)-045 propeller and for the two-blade NACA 10-(3)(08)-045 propeller over a range of advance ratio from 0.5 to 3.8, through a blade-angle range from 20 degrees to 55 degrees measured at the 0.75 radius. Maximum efficiencies of the order of 91.5 to 92 percent were obtained for the propellers. The propeller with the thinner airfoil sections over the outboard portion of the blades, the NACA 10-(3)(062)-045 propeller, had lower losses at high tip speeds, the difference amounting to about 5 percent at a helical tip Mach number of 1.10.
Aerodynamic forces and loadings on symmetrical circular-arc airfoils with plain leading-edge and plain trailing-edge flaps: From Summary: "An investigation has been made in the Langley two-dimensional low-turbulence tunnel and in the Langley two-dimensional low-pressure tunnel of 6- and 10-percent-thick symmetrical circular-arc airfoil sections at low Mach numbers and several Reynolds numbers. The airfoils were equipped with 0.15-chord plain leading-edge flaps and 0.20-chord plan trailing-edge flaps. The section lift and pitching-moment characteristics were determined for both airfoils with the flaps deflected individually and in combination."
An analysis of laminar free-convection flow and heat transfer about a flat plate paralled to the direction of the generating body force: From Introduction: "Although the final equations obtained by this method are the same as those of Schmidt and Beckmann, this more general approach not only clearly demonstrates the significance of all the important parameters and assumptions and hence leads to a better understanding of this type of flow but also indicates the quantitative limitations of the theory. In addition, the numerical solutions of references 2 and 3 are herein extended to cover a more complete range of parameters."
Analysis of Landing-Gear Behavior: From Summary: "This report presents a theoretical study of the behavior of the conventional type of oleo-pneumatic landing gear during the process of landing impact. The basic analysis is presented in a general form and treats the motions of the landing gear prior to and subsequent to the beginning of shock-strut deflection."
Analytical investigation of icing limit for diamond-shaped airfoil in transonic and supersonic flow: From Introduction: "The results presented herein were calculated for a symmetrical diamond airfoil at zero angle of attack for a range of airfoil-thickness ratios from 0.02 to 0.10, pressure altitude from sea level to 45,000 feet, and free-stream static temperatures to -.40^o F."
Analytical Investigation of Icing Limit for Diamond-Shaped Airfoil in Transonic and Supersonic Flow: Calculations have been made for the icing limit of a diamond airfoil at zero angle of attack in terms of the stream Mach number, stream temperature, and pressure altitude. The icing limit is defined as a wetted-surface temperature of 320 F and is related to the stream conditions by the method of Hardy. The results show that the point most likely to ice on the airfoil lies immediately behind the shoulder and is subject to possible icing at Mach numbers as high as 1.4.
Bearing Strengths of Some 75S-T6 and 14S-T6 Aluminum-Alloy Hand Forgings: Note presenting results from an investigation of bearing properties of some 75S-T6 and 14S-T6 aluminum-alloy hand forgings in the longitudinal and long transverse directions and in surface and center locations.
Behavior in pure bending of a long monocoque beam of circular-arc cross section: From Summary: "An analysis is made of the behavior under a loading of pure bending moment of a thin, infinitely long, pure-monocoque beam having a constant, doubly symmetric, circular-arc cross section. Bending moments, deflections, and stresses are obtained. The analysis shows a nonlinear behavior in bending which leads ultimately to a maximum amount and instability."
Calculation and Measurement of Normal Modes of Vibration of an Aluminum-Alloy Box Beam With and Without Large Discontinuities: Note presenting calculations of the lowest normal modes of vibration of three aluminum-alloy box beams using a matrix iteration method. An experimental confirmation of the theory is also carried out and includes a determination of natural frequencies and determination of normalized mode shapes are provided.
Calculation of the Shape of a Two-Dimensional Supersonic Nozzle in Closed Form: "The idea is advanced of making a supersonic nozzle by producing one, two, or three successive turns of the whole flow; with the result that the wall contour can be calculated exactly by means of the Prandtl-Meyer "Lost Solution" (p. 1).
Charts and approximate formulas for the estimation of aeroelastic effects of the lateral control of swept and unswept wings: Charts and approximate formulas are presented for the estimation of static aeroelastic effects on the spanwise lift distribution, rolling-moment coefficient, and rate of roll due to the deflection of ailerons on swept and unswept wings at subsonic and supersonic speeds. Some design considerations brought out by the results of this report are discussed. This report treats the lateral-control case in a manner similar to that employed in NACA Report 1140 for the symmetric-flight case, and is intended to be used in conjunction with NACA Report 1140 and the charts and formulas presented therein.
Charts and approximate formulas for the estimation of aeroelastic effects on the loading of swept and unswept wings: Charts and approximate formulas are presented for the estimation of aeroelastic effects on the spanwise lift distribution, lift-curve slope, aerodynamic center, and damping in roll of swept and unswept wings at subsonic and supersonic speeds. Some design considerations brought out by the results of this report are discussed.
Combined Effect of Damping Screens and Streams Convergence on Turbulence: Note presenting an analysis of the combined effect of a series of damping screens followed by an axisymmetric-stream convergence on the mean-square fluctuation-velocity intensities, scales, correlations, and one-dimensional spectra of a turbulence field convected by a main stream. Numerical results for the statistical quantities describing the turbulence field downstream of a screen-contraction configuration are obtained for the case of upstream isotropic turbulence.
Considerations on the effect of wind-tunnel walls on oscillating air forces for two-dimensional subsonic compressible flow: This report treats the effect of wind-tunnel walls on the oscillating two-dimensional air forces in a compressible medium. The walls are simulated by the usual method of placing images at appropriate distances above and below the wing. An important result shown is that, for certain conditions of wing frequency, tunnel height, and Mach number, the tunnel and wing may form a resonant system so that the forces on the wing are greatly changed from the condition of no tunnel walls. It is pointed out that similar conditions exist for three-dimensional flow in circular and rectangular tunnels and apparently, within certain Mach number ranges, in tunnels of nonuniform cross section or even in open tunnels or jets.
Deflection and Stress Analysis of Thin Solid Wings of Arbitrary Plan Form with Particular Reference to Delta Wings: "The structural analysis of arbitrary solid cantilever wings by small-deflection thin-plate theory is reduced to the solution of linear ordinary differential equations by the assumption that the chordwise deflections at any spanwise station may be expressed in the form of a power series in which the coefficients are functions of the spanwise coordinate. If the series is limited to the first two and three terms (that is, if linear and parabolic chordwise deflections, respectively, are assumed), the differential equations for the coefficients are solved exactly for uniformly loaded solid delta wings of constant thickness ratio. For cases for which exact solutions to the differential equations cannot be obtained, a numerical procedure is derived" (p. 1).
A Digital Automatic Multiple Pressure Recorder: Note presenting a machine which will automatically measure and record 100 pressures in a range from 5 to 65 inches of mercury, in approximately 2.5 minutes, to an accuracy of 0.1 inch of mercury. The method used is to compare the unknown pressures with a scanning pressure whose value at any instant is known in digitalized form.
Dynamics of mechanical feedback-type hydraulic servomotors under inertia loads: "An analysis of the dynamics of mechanical feedback-type hydraulic servomotors under inertia loads is developed and experimental verification is presented. The analysis, which is developed in terms of two physical parameters, yields direct expressions for the following dynamic responses: (1) the transient response to a step input and the maximum cylinder pressure during the transient and (2) the variation of amplitude attenuation and phase shift with the frequency of a sinusoidally varying input. The validity of the analysis is demonstrated by means of recorded transient and frequency responses obtained on two servomotors" (p. 1).
Effect of Drawbar Upstream Location on Air Velocity Distribution at the Inlet Face of Reactor Segment Designed by the General Electric Company: The results of flow tests on a drawbar for the General Electric reactor segment test in the MTR are reported. The drawbar is a T-shaped obstruction located as close to the upstream face of the reactor test segment as possible without serious flow distortion ; the drawbar is required for instrumentation leads and segment insertion and removal in the MTR. The effect of drawbar upstream distance on velocity distribution across the segment face is evaluated for several Reynolds numbers.
The Effect of Initial Curvature on the Strength of an Inelastic Column: From Summary: "The reduction in column strength due to initial curvature is determined theoretically for a pin-ended idealized inelastic H-section column. Equations relating load and lateral deflection are obtained which permit a systematic variation in the parameters representing the stress-strain properties, column proportions, and initial curvature of the column. The results, presented graphically, show the effect of various combinations of these parameters on column strength."
The Effect of Longitudinal Stiffeners Located on One Side of a Plate on the Compressive Buckling Stress of the Plate-Stiffener Combination: "The problem of buckling under uniform compression of flat, simply supported, rectangular plates equally spaced longitudinal stiffeners on one side of the plate is investigated. For the case of a plate with one, two, or infinitely many stiffeners, the analysis yields expressions for the effective moment of inertia of the stiffeners that can be used in conjunction with the buckling charts previously presented in NACA TN 1825" (p. 1).
Equations, Tables, and Charts for Compressible Flow: "This report, which is a revision and extension of NACA-TN-1428, presents a compilation of equations, tables, and charts useful in the analysis of high-speed flow of a compressible fluid. The equations provide relations for continuous one-dimensional flow, normal and oblique shock waves, and Prandtl-Meyer expansions for both perfect and imperfect gases. The tables present useful dimensionless ratios for continuous one-dimensional flow and for normal shock waves as functions of Mach number for air considered as a perfect gas" (p. 613).
Estimated power reduction by water injection in a nonreturn supersonic wind tunnel: Report presenting a simplified analysis to estimate the extent to which the pressure ratio and power of a nonreturn supersonic wind tunnel operating in the low supersonic Mach number range can be reduced by the evaporation of water injected into the diffuser. It appears to be possible to reduce the power by as much as 20 percent for a typical example of a tunnel operating at Mach number 1.4.
Estimation of the Maximum Angle of Sideslip for Determination of Vertical-Tail Loads in Rolling Maneuvers: Report includes the National Advisory Committee for Aeronautics Technical Reports 1135 through 1157. Recent experiences have indicated that angles of sideslip in rolling maneuvers may be critical in the design of vertical tails for current research airplanes having weight distributed mainly along the fuselage. Previous investigations have indicated the seriousness of the problem for the World War II type of airplane. This report presents some preliminary calculations for airplanes of current design, particularly with weight distributed primarily along the fuselage.
Flight Investigation of the Stability and Control Characteristics of a 0.13-Scale Model of the Convair XFY-1 Vertically Rising Airplane During Constant-Altitude Transitions, TED No. NACA DE 368: "An investigation is being conducted to determine the dynamic stability and control characteristics of a 0.13-scale flying model of the Convair XFY-1 vertically rising airplane. This paper presents the results of flight tests to determine the stability and control characteristics of the model during constant-altitude slow transitions from hovering to normal unstalled forward flight. The tests indicated that the airplane can be flown through the transition range fairly easily although some difficulty will probably encountered in controlling the yawing motions at angles of attack between about 60 and 40" (p. 1).
Flight Tests of a 0.13-Scale Model of the Convair XFY-1 Vertically Rising Airplane in a Setup Simulating that Proposed for Captive-Flight Tests in a Hangar, TED No. NACA DE 368: "An experimental investigation has been conducted to determine the dynamic stability and control characteristics of a 0.13-scale free-flight model of the Convair XFY-1 airplane in test setups representing the setup proposed for use in the first flight tests of the full-scale airplane in the Moffett Field airship hangar. The investigation was conducted in two parts: first, tests with the model flying freely in an enclosure simulating the hangar, and second, tests with the model partially restrained by an overhead line attached to the propeller spinner and ground lines attached to the wing and tail tips. The results of the tests indicated that the airplane can be flown without difficulty in the Moffett Field airship hangar if it does not approach too close to the hangar walls" (p. 1).
Heat of Combustion of the Product Formed by the Reaction of Diborane with 1,3-Butadiene: Report presenting the net heat of combustion of the product formed by the reaction of diborane with 1,3-butadiene was found to be 18,700 plus or minus 150 Btu per pound for the reaction of liquid fuel to gaseous carbon dioxide, gaseous water, and solid boric oxide. The measurements were made in a Parr oxygen-bomb calorimeter, and the combustion was believed to be 98 percent complete.
High-Speed Wind-Tunnel Tests of a 1/16-Scale Model of the D-558 Research Airplane Lift and Drag Characteristics of the D-558-1 and Various Wing and Tail Configurations: "Tests were made in the Langley 8-foot high-speed tunnel to investigate the aerodynamic characteristics of the D-558-1 airplane and various wing and tail configurations on the D-558-1 fuselage. The various wing and tail configurations were tested to determine the aerodynamic effects of aspect ratio and sweep for suitable use on the second phase of the D-558 project (D-558-2). The tests were conducted through a speed range from a Mach number of 0.40 to approximately 0.94" (p. 1).
Icing protection for a turbojet transport airplane : heating requirements methods of protection, and performance penalties: Report analyzing and discussing the problems associated with providing icing protection for the critical components of a typical turbojet transport airplane operating over a range of probable icing conditions. Heating requirements for several thermal methods of protection are evaluated and the airplane performance penalties associated with providing protection from various energy sources are provided.
Icing Protection for a Turbojet Transport Airplane: Heating Requirements, Methods of Protection, and Performance Penalties: "The problems associated with providing icing protection for the critical components of a typical turbojet transport airplane operating over a range of probable icing conditions are analyzed and discussed. Heating requirements for several thermal methods of protection are evaluated and the airplane performance penalties associated with providing this protection from various energy sources are assessed. The continuous heating requirements for icing protection and the associated airplane performance penalties for the turbojet transport are considerably increased over those associated with lower-speed aircraft" (p. 1).
Investigation of Gases Evolved During Firing of Vitreous Coatings on Steel: Note presenting an investigation of the gases evolved during the firing of vitreous coatings. The scope of the investigation included an examination of gas evolution with a microscope while specimens were being fired, examinations of fired specimens for changes in bubble structure with firing time, examination of changes in normal gas evolution when water-free enamels were used, analysis with the mass spectrometer of gases trapped in the bubble structure, determination of the source of carbon gases in the bubble structure with radioactive carbon as a tracer, and determination of the effect of various pretreatments of the clay used for suspending the coating slip on the resulting bubble structure of the fired specimens.
Laminar Boundary Layer on Cone in Supersonic Flow at Large Angle of Attack: "The laminar boundary-layer flow about a circular cone at large angles of attack to a supersonic stream has been analyzed in the plane of symmetry by a method applicable in general to the flow about conical bodies. At the bottom of the cone, velocity profiles were obtained showing the expected tendency of the boundary layer to become thinner on the under side of the cone as the angle of attack is increased. At the top of the cone, the analysis failed to yield unique solutions except for small angles of attack" (p. 1).
On the Stability of the Laminar Mixing Region Between Two Parallel Streams in a Gas: Note presenting a study of the stability of the mixing of two streams both for the interest in the problem and for clarifying certain points in the basic stability theory. Results show that when the relative speed of the two parallel streams exceeds the sum of their velocities of sound, subsonic oscillations cannot occur and the mixing region can be expected to be stable with respect to small disturbances.
On the Use of a Damped Sine-Wave Elevator Motion for Computing the Design Maneuvering Horizontal-Tail Load: Note presenting a damped sine-wave elevator motion used as a basis for computing the design maneuvering load on the horizontal tail. The results indicated that the maneuvering tail-load variation computed by operational methods with the assumed damped sine-wave elevator motion agreed closely with the loads computed by a method currently used by the US Air Force.
On Transonic Flow Past a Wave-Shaped Wall: "This report is an extension of a previous investigation (described in NACA rep. 1069) concerned with the solution of the nonlinear differential equation for transonic flow past a wavy wall. In the present work several new notions are introduced which permit the solution of the recursion formulas arising from the method of integration in series. In addition, a novel numerical tests of convergence, applied to the power series (in transonic similarity parameter) representing the local Mach number distribution at the boundary, indicates that smooth symmetrical potential flow past the wavy wall is no longer possible once the critical value of the stream Mach number has been exceeded" (p. 1).
On Traveling Waves in Beams: Note presenting the basic equations of Timoshenko for the motion of vibrating non-uniform beams, which allow for effects of transverse shear deformation and rotary inertia, in several forms, including one in which the equations are written in the directions of the characteristics. Numerical traveling-wave solutions are obtained for some elementary problems of finite uniform beams for which the propagation velocities of bending and shear discontinuities are taken to be equal.
One-Dimensional Analysis of Choked-Flow Turbines: "Turbines for most applications requiring high work output per stage have one or more blade rows which are choked. This analysis indicated that the area ratios and equivalent blade speed are the controlling factors in the design and operation of such turbines. Six criteria are stated that will aid in establishing from test data of multistage turbines which blade rows are choked and which are not" (p. 1).
The Planing Characteristics of Two v-Shaped Prismatic Surfaces Having Angles of Dead Rise of 20 Degrees and 40 Degrees: "The principal planing characteristics have been obtained for two V-shaped prismatic surfaces having angles of dead rise of 20 degrees and 40 degrees. The load, wetted lengths, resistance, center-of-pressure location, and limited drag data are presented for speed coefficients up to 25.0, beam-loading coefficients from 0.85 to 87.33, keel-wetted-length-beam-ratios up to approximately 8.0, and trims up to 30 degrees. The data indicate that, for a given condition of load, speed, and trim, the wetted length, the distance of the center of pressure from the trailing edge, and the drag increase with an increase in the angle of dead rise" (p. 1).
Power-off flare-up tests of a model helicopter rotor in vertical autorotation: Report presenting the results of an experimental investigation of the problem of reducing the descending velocity of a helicopter model in steady vertical autorotation by expending the kinetic energy of the rotor in a collective-pitch flare. Test data were obtained over a wide range of operating conditions from a freely falling model rotor restrained laterally by a guide wire. Results regarding justification of initial conditions, effect or rate of change of blade pitch angle, effect of final blade pitch angle, effect of rotor inertia and disk loading, and semiempirical theory are provided.
Reflection of Weak Shock Wave From a Boundary Layer Along a Flat Plate 2: Interaction of Oblique Shock Wave With a Laminar Boundary Layer Analyzed by Differential-Equation Method: Note presenting an investigation of the interaction of an oblique shock with a laminar boundary layer in a compressible supersonic stream. This report is a complement to previous report and uses the differential equation method.
A Special Investigation to Develop a General Method for Three-Dimensional Photoelastic Stress Analysis: The method of strain measurement after annealing is reviewed and found to be satisfactory for the materials available in this country. A new general method is described for the photoelastic determination of the principal stresses at any point of a general body subjected to arbitrary load. The method has been applied to a sphere subjected to diametrical compressive loads. The results show possibilities of high accuracy.
Stability and Control Characteristics at Low Speed of a 1/10-Scale Model of MX-1554A Design: Report discussing an investigation of the low-speed stability and control characteristics of a model of the proposed MX-1554A design with a triangular wing and triangular stabilizing surfaces. It also includes the effect of wing incidence, slotted flaps, wing and tail height, external tanks and speed brakes, ground board, spoilers, tip ailerons, flaps, differential tail deflection, and an unswept wing on stability, control, aerodynamic, longitudinal, and lateral characteristics.
Steady Vibrations of Wing of Circular Plan Form and Theory of Wing of Circular Plan Form: This paper treats the problem of determining the lift, moment, and induced drag of a thin wing of circular plan form in uniform incompressible flow on the basis of linearized theory. As contrasted to a similar paper by Kinner, in which the acceleration potential method was used, the present paper utilizes the concept of the velocity potential. Calculations of the lift and moment are presented for several deformed shapes.
A Study of Inviscid Flow About Airfoils at High Supersonic Speeds: Steady flow about curved airfoils is investigated analytically, first assuming air behaves as an ideal gas, and then assuming it behaves as a thermally perfect, calorically imperfect gas. Conclusions are drawn from the study.
Study of pressure effects on vaporization rate of drops in gas streams: Report presenting the determination of the rate of vaporization of a pure liquid from a spherical surface exposed to a gas stream of varying static pressure, which required the use of a heat-balance equation. Results regarding the effect of pressure on Nusselt number, momentum-transfer groups, application of momentum-transfer groups to heat and mass transfer, and effect of pressure on driving potential are provided.
A Study of the Application of Power-Spectral Methods of Generalized Harmonic Analysis to Gust Loads on Airplanes: Note presenting an examination of the applicability of some results from the theory of generalized harmonic analysis (or power-spectral analysis) to the analysis of gust loads on airplanes in continuous rough air. The general relations for linear systems between power spectrums of a random input disturbance and an output response are used to relate the spectrum of airplane load in rough air to the spectrum of atmospheric gust velocity.
Theoretical investigation of the longitudinal response characteristics of a swept-wing fighter airplane having a pitch-attitude control system: Report presenting a theoretical analysis made of a pitch-attitude control system as applied to a swept-wing fighter airplane. The system is investigated with and without pitch-rate feedback. The effects of varying gain settings, Mach number, altitude, and variations of elevator deflection, normal acceleration, and flight path are provided.
Transonic Aerodynamic and Trim Characteristics of 1/15-Scale Models of the Convair MX-1964 Airplane With Indented Fuselage: Report presenting an investigation of two scale models of the MX-1964 airplane with indented fuselage conducted in the transonic tunnel. One model had a plane delta wing with full-span elevons and the other had a cambered delta wing with partial-span elevons. Results regarding the aerodynamic characteristics and effect of elevon deflection are provided.
Transverse Vibrations of Hollow Thin-Walled Cylindrical Beams: "The variational principle, differential equations, and boundary conditions considered appropriate to the analysis of transverse vibrations of hollow thin-walled cylindrical beams are shown. General solutions for the modes and frequencies of cantilever and free-free cylindrical beams of arbitrary cross section but of uniform thickness are given. The combined influence of the secondary effects of transverse shear deformation, shear lag, and secondary effects of transverse shear deformation, shear lag, and longitudinal inertia is shown in the form of curves for cylinders of rectangular cross section and uniform thickness" (p. 1).
Flame velocities of propane- and ethylene-oxygen-nitrogen mixtures: Report presenting the laminar flame velocities of propane and ethylene with various oxygen-nitrogen mixtures as determined from schileren photographs of Bunsen-type flames. Flame velocity was determined as a function of equivalence ratio for each oxygen-nitrogen mixture at two initial temperatures.

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