National Advisory Committee for Aeronautics (NACA) - 37 Matching Results

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A Simplified Method of Elastic-Stability Analysis for Thin Cylindrical Shells

Description: "This paper develops a new method for determining the buckling stresses of cylindrical shells under various loading conditions. In part I, the equation for the equilibrium of cylindrical shells introduced by Donnell in NACA report no. 479 to find the critical stresses of cylinders in torsion is applied to find critical stresses for cylinders with simply supported edges under other loading conditions. In part II, a modified form of Donnell's equation for the equilibrium of thin cylindrical shell… more
Date: March 20, 1947
Creator: Batdorf, S. B.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Critical Stress of Thin-Walled Cylinders in Axial Compression

Description: Empirical design curves are presented for the critical stress of thin-wall cylinders loaded in axial compression. These curves are plotted in terms of the nondimensional parameters of small-deflection theory and are compared with theoretical curves derived for the buckling of cylinders with simply supported and clamped edges. An empirical equation is given for the buckling of cylinders having a length-radius ratio greater than about 0.75.
Date: March 20, 1947
Creator: Batdorf, S. B.; Schildcrout, Murry & Stein, Manuel
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Flight Investigation on a Fighter-Type Airplane of Factors Which Affect the Loads and Load Distributions on the Vertical Tail Surfaces During Rudder Kicks and Fishtails

Description: "Results are presented of a flight investigation conducted on a fighter-type airplane to determine the factors which affect the loads and load distributions on the vertical tail surfaces in maneuvers. An analysis is made of the data obtained in steady flight, rudder kicks, and fishtail maneuvers. For the rudder kicks, the significant loads were the "deflection load" resulting from an abrupt control deflection and the "dynamic load" consisting of a load corresponding to the new static equilibriu… more
Date: 1947
Creator: Boshar, John
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Damping in pitch and roll of triangular wings at supersonic speeds

Description: A method is derived for calculating the damping coefficients in pitch and roll for a series of triangular wings and a restricted series of sweptback wings at supersonic speeds. The elementary "supersonic source" solution of the linearized equation of motion is used to find the potential function of a line of doublets, and the flows are obtained by surface distributions of these doublet lines. The damping derivatives for triangular wings are found to be a function of the ratio of the tangent of … more
Date: December 12, 1947
Creator: Brown, Clinton E. & Adams, Mac C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Design and performance of family of diffusing scrolls with mixed-flow impeller and vaneless diffuser

Description: A family of diffusing scrolls was designed for use with a mixed-flow impeller and a small-diameter vaneless diffuser. The design theory, intended to maintain a uniform pressure around the scroll inlet, permits determination of the position of scroll cross sections of preassigned area by considering the radial variation in fluid density and the effects of friction along the scroll. Inasmuch as the design method leaves the cross-sectional shape undetermined, the effect of certain variations in sc… more
Date: October 1947
Creator: Brown, W. Byron & Bradshaw, Guy R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Experimental investigation of the effects of viscosity on the drag and base pressure of bodies of revolution at a Mach number 1.5

Description: Models were tested to evaluate effects of Reynolds number for both laminar and turbulent boundary layers. Principal geometric variables investigated were afterbody shape and length-diameter ratio. Force tests and base-pressure measurements were made. Schlieren photographs were used to analyze the effects of viscosity on flow separation and shock-wave configuration and to verify the condition of the boundary layer as deduced from the force tests. The results are discussed and compared with theor… more
Date: January 31, 1947
Creator: Chapman, Dean R. & Perkins, Edward W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Effect of combustor-inlet conditions on performance of an annular turbojet combustor

Description: From Summary: "The combustion performance, and particularly the phenomenon of altitude operational limits, was studied by operating the annular combustor of a turbojet engine over a range of conditions of air flow, inlet pressure, inlet temperature, and fuel flow. Information was obtained on the combustion efficiencies, the effect on combustion of inlet variables, the altitude operational limits with two different fuels, the pressure losses in the combustor, the temperature and velocity profile… more
Date: March 21, 1947
Creator: Childs, J. Howard; McCafferty, Richard J. & Surine, Oakley W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Spark-Timing Control Based on Correlation of Maximum-Economy Spark Timing, Flame-Front Travel, and Cylinder-Pressure Rise

Description: "An investigation was conducted on a full-scale air-cooled cylinder in order to establish an effective means of maintaining maximum-economy spark timing with varying engine operating conditions. Variable fuel-air-ratio runs were conducted in which relations were determined between the spark travel, and cylinder-pressure rise. An instrument for controlling spark timing was developed that automatically maintained maximum-economy spark timing with varying engine operating conditions" (p. 1).
Date: 1947
Creator: Cook, Harvey A.; Heinicke, Orville H. & Haynie, William H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Further experiments on the flow and heat transfer in a heated turbulent air jet

Description: "Measurements have been made of the mean-total-head and mean-temperature fields in a round turbulent jet with various initial temperatures. The results show that the jet spreads more rapidly as its density becomes lower than that of the receiving medium, even when the difference is not sufficiently great to cause dynamic-pressure function. Rough analytical considerations have given the same relative spread. The effective "turbulent Prandtl number" for a section of the fully developed jet was fo… more
Date: August 18, 1947
Creator: Corrsin, Stanley & Uberoi, Mahinder S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Theoretical study of air forces on an oscillating or steady thin wing in a supersonic main stream

Description: From Summary: "A theoretical study, based on the linearized equations of motion for small disturbance, is made of the air forces on wings of general plan forms moving forward at a constant supersonic speed. The boundary problem is set up for both the harmonically oscillating and the steady conditions. Two types of boundary conditions are distinguished, which are designated "purely supersonic" and "mixed supersonic." the method is illustrated by applications to a number of examples for both the … more
Date: June 4, 1947
Creator: Garrick, I. E. & Rubinow, S. I.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Analysis of Performance of Jet Engine From Characteristics of Components 1: Aerodynamic and Matching Characteristics of Turbine Component Determined With Cold Air

Description: "The performance of the turbine component of an NACA research jet engine was investigated with cold air. The interaction and the matching of the turbine with the NACA eight-stage compressor were computed with the combination considered as a jet engine. The over-all performance of the engine was then determined. The internal aerodynamics were studied to the extent of investigating the performance of the first stator ring and its influence on the turbine performance" (p. 397).
Date: June 6, 1947
Creator: Goldstein, Arthur W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Isolated and Cascade Airfoils With Prescribed Velocity Distribution

Description: "An exact solution of the problem of designing an airfoil with a prescribed velocity distribution on the suction surface in a given uniform flow of an incompressible perfect fluid is obtained by replacing the boundary of the airfoil by vortices. By this device, a method of solution is developed that is applicable both to isolated airfoils and to airfoils in cascade. The conformal transformation of the designed airfoil into a circle can then be obtained and the velocity distribution at any angle… more
Date: 1947
Creator: Goldstein, Arthur W. & Jerison, Meyer
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Frequency-Response Method for Determination of Dynamic Stability Characteristics of Airplanes With Automatic Controls

Description: "A frequency-response method for determining the critical control-gearing and hunting oscillations of airplanes with automatic pilots is presented. The method is graphical and has several advantages over the standard numerical procedure based on Routh's discriminant. The chief advantage of the method is that direct use can be made of the measured response characteristics of the automatic pilot. This feature is especially useful in determining the existence, amplitude, and frequency of the hunti… more
Date: 1947
Creator: Greenberg, Harry
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Two-dimensional unsteady lift problems in supersonic flight

Description: The variation of pressure distribution is calculated for a two-dimensional supersonic airfoil either experiencing a sudden angle-of-attack change or entering a sharp-edge gust. From these pressure distributions the indicial lift functions applicable to unsteady lift problems are determined for two cases. Results are presented which permit the determination of maximum increment in lift coefficient attained by an unrestrained airfoil during its flight through a gust. As an application of these re… more
Date: December 5, 1947
Creator: Heaslet, Max A. & Lomax, Harvard
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Voltera's Solution of the Wave Equation as Applied to Three-Dimensional Supersonic Airfoil Problems

Description: "A surface integral is developed which yields solutions of the linearized partial differential equation for supersonic flow. These solutions satisfy boundary conditions arising in wing theory. Particular applications of this general method are made, using acceleration potentials, to flat surfaces and to uniformly loaded lifting surfaces. Rectangular and trapezoidal plan forms are considered along with triangular forms adaptable to swept-forward and swept-back wings. The case of the triangular p… more
Date: September 1947
Creator: Heaslet, Max A.; Lomax, Harvard & Jones, Arthur L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Effects of temperature distribution and elastic properties of materials on gas-turbine-disk stresses

Description: From Summary: "Calculations were made to determine the influence of changes in temperature distribution and in elastic material properties on calculated elastic stresses for a typical gas-turbine disk. Severe temperature gradients caused thermal stresses of sufficient magnitude to reduce the operating safety of the disk. Small temperature gradients were found to be desirable because they produced thermal stresses that subtracted from the centrifugal stresses in the region of the rim."
Date: March 29, 1947
Creator: Holms, Arthur G. & Faldetta, Richard D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Theoretical motions of hydrofoil systems

Description: "Results are presented of an investigation that has been undertaken to develop theoretical methods of treating the motions of hydrofoil systems and to determine some of the important parameters. Variations of parameters include three distributions of area between the hydrofoils, two rates of change of downwash angle with angle of attack, three depths of immersion, two dihedral angles, two rates of change of lift with immersion, three longitudinal hydrofoil spacings, two radii of gyration in pit… more
Date: May 9, 1947
Creator: Imlay, Frederick H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Effects of sweepback on boundary layer and separation

Description: "Following a law of stress adopted in the Navier-Stokes equations, the configuration of the viscous flow in planes at right angles to the axis of an infinite cylinder is found to be independent of the axial motion of the cylinder. In the limiting case of a yawed or swept wing of very high aspect ratio, certain boundary-layer and separation phenomena are thus determined independently by the crosswise component of velocity. It follows that the effect of sweepback is to increase the area of stable… more
Date: July 1947
Creator: Jones, Robert T.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Subsonic flow over thin oblique airfoils at zero lift

Description: A previous report gave calculations for the pressure distribution over thin oblique airfoils at supersonic speed. The present report extends the calculations to subsonic speeds. It is found that the flows again can be obtained by the superposition of elementary conical flow fields. In the case of the swept-back wing the pressure distributions remain qualitatively similar at subsonic and supersonic speeds. Thus a distribution similar to the Ackeret type of distribution appears on the root sectio… more
Date: May 1947
Creator: Jones, Robert T.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Wing plan forms for high-speed flight

Description: From Summary: "It is pointed out that, in the case of an airfoil of infinite aspect ratio moving at an angle of sideslip, the pressure distribution is determined solely by that component of the motion in a direction normal to the leading edge. It follows that the attachment of plane waves to the airfoil at near-sonic or supersonic speeds (Ackeret theory) may be avoided and the pressure drag may be reduced by the use of plan forms in which the angle of sweepback is greater than the Mach angle."
Date: 1947
Creator: Jones, Robert T.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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On Similarity Rules for Transonic Flows

Description: "A method used by Tsien to derive similarity rules for hypersonic flows is utilized to derive Von Karman's similarity rules for transonic flows. At the lower limit of the transonic region of flow the theory yields a formula for the critical stream Mach numbers of a given family of symmetrical profiles. It is further shown that this formula can also be obtained by means of the Prandtl-Glauert small-perturbation method" (p. 83).
Date: December 9, 1947
Creator: Kaplan, Carl
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Interference Method for Obtaining the Potential Flow Past an Arbitrary Cascade of Airfoils

Description: "A procedure is presented for obtaining the pressure distribution on an arbitrary airfoil section in cascade in a two-dimensional, incompressible, and nonviscous flow. The method considers directly the influence on a given airfoil of the rest of the cascade and evaluates this interference by an iterative process, which appeared to converge rapidly in the cases tried (about unit solidity, stagger angles of 0 degree and 45 degrees). Two variations of the basic interference calculations are descri… more
Date: January 10, 1947
Creator: Katzoff, S.; Finn, Robert S. & Laurence, James C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A General Small-Deflection Theory for Flat Sandwich Plates

Description: "A small-deflection theory is developed for the elastic behavior of orthotropic flat plates in which deflections due to shear are taken into account. In this theory, which covers all types of flat sandwich construction, a plate is characterized by seven physical constants (five stiffnesses and two Poisson ratios) of which six are independent. Both the energy expression and the differential equations are developed. Boundary conditions corresponding to simply supported, clamped, and elastically r… more
Date: September 30, 1947
Creator: Libove, Charles & Batdorf, S. B.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Dislocation Theory of the Fatigue of Metals

Description: "A dislocation theory of fatigue failure for annealed solid solutions is presented. On the basis of this theory, an equation giving the dependence of the number of cycles for failure on the stress, the temperature, the material parameters, and the frequency is derived for uniformly stressed specimens. The equation is in quantitative agreement with the data" (p. 183).
Date: September 12, 1947
Creator: Machlin, E. S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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