National Advisory Committee for Aeronautics (NACA) - 1,423 Matching Results

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Investigation of the aerodynamic characteristics of a model wing-propeller combination and of the wing and propeller separately at angles of attack up to 90 degrees

Description: This report presents the results of an investigation conducted in the Langley 300 mph 7- by 10-foot wind tunnel for the purpose of determining the aerodynamic characteristics of a model wing-propeller combination, and of the wing and propeller separately at angles of attack up to 90 degrees. The tests covered thrust coefficients corresponding to free-stream velocities from zero forward speed to the normal range of cruising speeds. The results indicate that increasing the thrust coefficient incr… more
Date: 1956
Creator: Kuhn, Richard E. & Draper, John W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A Thermal Equation for Flame Quenching

Description: "An approximate thermal equation was derived for quenching distance based on a previously proposed diffusional treatment. The quenching distance was expressed in terms of the thermal conductivity, the fuel mole fraction, the heat capacity, the rate of the rate-controlling chemical reaction, a constant that depends on the geometry of the quenching surface, and one empirical constant. The effect of pressure on quenching distance was shown to be inversely proportional to the pressure dependence of… more
Date: December 6, 1954
Creator: Potter, A. E., Jr. & Berlad, A. L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Charts for Estimating Performance of High-Performance Helicopters

Description: "Theoretically derived charts showing the profile-drag-thrust ratio are presented for helicopter rotors operating in forward flight and having hinged rectangular blades with a linear twist of 0 degree, 8 degrees, and 16 degrees. The charts, showing the profile-drag characteristics of the rotor for various combinations of pitch angle, ratio of thrust coefficient to solidity, and a parameter representing shaft power input, are presented for tip-speed ratios ranging from 0.05 to 0.50. Also present… more
Date: November 23, 1955
Creator: Gessow, Alfred & Tapscott, Robert J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Plastic Deformation of Aluminum Single Crystals at Elevated Temperatures

Description: "This report describes the results of a comprehensive study of plastic deformation of aluminum single crystals over a wide range of temperatures. The results of constant-stress creep tests have been reported for the temperature range from 400 degrees to 900 degrees F. For these tests, a new capacitance-type extensometer was designed. This unit has a range of 0.30 inch over which the sensitivity is very nearly linear and can be varied from as low a sensitivity as is desired to a maximum of 20 mi… more
Date: December 29, 1953
Creator: Johnson, R. D.; Young, A. P. & Schwope, A. D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Theory of wing-body drag at supersonic speeds

Description: "The relation of Whitcomb's "area rule" to the linear formulas for wave drag at lightly supersonic speeds is discussed. By adopting an approximate relation between the source strength and the geometry of a wing-body combination, the wave-drag theory is expressed in terms involving the areas intercepted by oblique planes or Mach planes. The resulting formulas are checked by comparison with the drag measurements obtained in wind-tunnel experiments and in experiments with falling models in free ai… more
Date: July 8, 1953
Creator: Jones, Robert T.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A theoretical study of the effect of forward speed on the free-space sound-pressure field around propellers

Description: Report presenting an analysis of the sound-pressure field of a rotating propeller in forward flight in free space by replacing the normal-pressure distribution over the propeller associated with thrust and torque by a distribution of acoustic pressure doublets acting at the propeller disk. The result is presented for a moving and a fixed observer.
Date: 1954
Creator: Garrick, I. E. & Watkins, Charles E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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General Theory of Aerodynamic Instability and the Mechanism of Flutter

Description: "The aerodynamic forces on an oscillating airfoil or airfoil-aileron combination of three independent degrees of freedom were determined. The problem resolves itself into the solution of certain definite integrals, which were identified as Bessel functions of the first and second kind, and of zero and first order. The theory, based on potential flow and the Kutta condition, is fundamentally equivalent to the conventional wing section theory relating to the steady case" (p. 291).
Date: May 2, 1934
Creator: Theodorsen, Theodore
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Blockage Corrections for Three-Dimensional-Flow Closed-Throat Wind Tunnels, with Consideration of the Effect of Compressibility

Description: "Theoretical blockage corrections are presented for a body of revolution and for a three-dimensional, unswept wing in a circular or rectangular wind tunnel. The theory takes account of the effects of the wake and of the compressibility of the fluid, and is based on the assumption that the dimensions of the model are small in comparison with those of the tunnel throat. Formulas are given for correcting a number of the quantities, such as dynamic pressure and Mach number, measured in wind tunnel … more
Date: 1950
Creator: Herriot, John G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Theory of the Pitot and Venturi Tubes, Part 2

Description: Report discussing several aspects of pitot and venturi tubes, including the energy equation for steady adiabatic flow, introduction of mean speed into the energy equation, isentropic flow of an ideal gas, the theory of the pitot tube, and the theory of the venturi meter.
Date: 1989?
Creator: Buckingham, E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Applications of Modern Hydrodynamics to Aeronautics Part 1: Fundamental Concepts and the Most Important Theorems. Part 2: Applications

Description: A discussion of the principles of hydrodynamics of nonviscous fluids in the case of motion of solid bodies in a fluid is presented. Formulae are derived to demonstrate the transition from the fluid surface to a corresponding 'control surface'. The external forces are compounded of the fluid pressures on the control surface and the forces which are exercised on the fluid by any solid bodies which may be inside of the control surfaces.
Date: 1979%
Creator: Prandtl, L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Minimum Induced Drag of Aerofoils

Description: Equations are derived to demonstrate which distribution of lifting elements result in a minimum amount of aerodynamic drag. The lifting elements were arranged (1) in one line, (2) parallel lying in a transverse plane, and (3) in any direction in a transverse plane. It was shown that the distribution of lift which causes the least drag is reduced to the solution of the problem for systems of airfoils which are situated in a plane perpendicular to the direction of flight.
Date: 1979-12?
Creator: Munk, Max M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Aerodynamic Forces on Airship Hulls

Description: The new method for making computations in connection with the study of rigid airships, which was used in the investigation of Navy's ZR-1 by the special subcommittee of the National Advisory Committee for Aeronautics appointed for this purpose is presented. The general theory of the air forces on airship hulls of the type mentioned is described and an attempt was made to develop the results from the very fundamentals of mechanics.
Date: 1979%
Creator: Munk, Max M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Inertia Coefficients of an Airship in a Frictionless Fluid

Description: The apparent inertia of an airship hull is examined. The exact solution of the aerodynamical problem is studied for hulls of various shapes with special attention given to the case of an ellipsoidal hull. So that the results for the ellipsoidal hull may be readily adapted to other cases, they are expressed in terms of the area and perimeter of the largest cross section perpendicular to the direction of motion by means of a formula involving a coefficient kappa which varies only slowly when the … more
Date: 1924
Creator: Bateman, H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Flow and Drag Formulas for Simple Quadrics

Description: The pressure distribution and resistance found by theory and experiment for simple quadrics fixed in an infinite uniform stream of practically incompressible fluid are calculated. The experimental values pertain to air and some liquids, especially water; the theoretical refer sometimes to perfect, again to viscid fluids. Formulas for the velocity at all points of the flow field are given. Pressure and pressure drag are discussed for a sphere, a round cylinder, the elliptic cylinder, the prolate… more
Date: December 1979
Creator: Zahm, A. F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Flow and Force Equations for a Body Revolving in a Fluid

Description: A general method for finding the steady flow velocity relative to a body in plane curvilinear motion, whence the pressure is found by Bernoulli's energy principle is described. Integration of the pressure supplies basic formulas for the zonal forces and moments on the revolving body. The application of the steady flow method for calculating the velocity and pressure at all points of the flow inside and outside an ellipsoid and some of its limiting forms is presented and graphs those quantities … more
Date: December 1979
Creator: Zahm, A. F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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General Potential Theory of Arbitrary Wing Sections

Description: The problem of determining the two dimensional potential flow around wing sections of any shape is examined. The problem is condensed into the compact form of an integral equation capable of yielding numerical solutions by a direct process. An attempt is made to analyze and coordinate the results of earlier studies relating to properties of wing sections. The existing approximate theory of thin wing sections and the Joukowski theory with its numerous generalizations are reduced to special cases… more
Date: November 4, 1932
Creator: Theodorsen, T. & Garrick, I. E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Impingement of Cloud Droplets on a Cylinder and Procedure for Measuring Liquid-Water Content and Droplet Sizes in Supercooled Clouds by Rotating Multicylinder Method

Description: "Evaluation of the rotating multicylinder method for the measurement of droplet-size distribution, volume-median droplet size, and liquid-water content in clouds showed that small uncertainties in the basic data eliminate the distinction between different cloud droplet-size distributions and are a source of large errors in the determination of the droplet size. Calculations of the trajectories of cloud droplets in incompressible and compressible flow fields around a cylinder were performed on a… more
Date: September 5, 1952
Creator: Brun, R. J.; Lewis, W.; Perkins, P. J. & Serafini, J. S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Determination of Stresses in Gas-turbine Disks Subjected to Plastic Flow and Creep

Description: From Summary: "A finite-difference method previously presented for computing elastic stresses in rotating disks is extended to include the computation of the disk stresses when plastic flow and creep are considered. A finite-difference method is employed to eliminate numerical integration and to permit nontechnical personnel to make the calculations with a minimum of engineering supervision. Illustrative examples are included to facilitated explanation of the procedure by carrying out the compu… more
Date: 1948
Creator: Millenson, M. B. & Manson, S. S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Design of Wind Tunnels and Wind Tunnel Propellers, 2

Description: Report presenting a continuation of a previous study in order to supply further data to the designers of wind tunnels. Particular emphasis was placed on the study of directional variation in the wind stream. The results indicated that placing radial vanes directly before the propeller actually increased the efficiency of the tunnel to a considerable extent.
Date: 1921
Creator: Norton, F. H. & Warner, E. P.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Propeller charts for the determination of the rotational speed for the maximum ratio of the propulsive efficiency to the specific fuel consumption

Description: A set of propeller operating efficiency charts, based on a coefficient from which the propeller rotational speed has been eliminated, is presented. These charts were prepared with data obtained from tests of full-size metal propellers in the NACA propeller-research tunnel. Working charts for nine propeller-body combinations are presented, including results from tests of dual-rotating propellers. These charts are to be used in the calculation of the range and the endurance of airplanes equipped … more
Date: December 11, 1940
Creator: Biermann, David & Conway, Robert N.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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High-Speed Tests of a Model Twin-Engine Low-Wing Transport Airplane

Description: Report presents the results of force tests made of a 1/8-scale model of a twin-engine low-wing transport airplane in the NACA 8-foot high-speed tunnel to investigate compressibility and interference effects of speeds up to 450 miles per hour. In addition to tests of the standard arrangement of the model, tests were made with several modifications designed to reduce the drag and to increase the critical speed.
Date: 1942
Creator: Becker, John V. & Leonard, Lloyd H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The mean aerodynamic chord and the aerodynamic center of a tapered wing

Description: A preliminary study of pitching-moment data on tapered wings indicated that excellent agreement with test data was obtained by locating the quarter-chord point of the average chord on the average quarter-chord point of the semispan. The study was therefore extended to include most of the available data on tapered-wing models tested by the NACA.
Date: June 16, 1942
Creator: Diehl, Walter S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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On a New Method for Calculating the Potential Flow Past a Body of Revolution

Description: "A new method is presented for obtaining the velocity potential of the flow about a body of revolution moving uniformly in the direction of its axis of symmetry in a fluid otherwise at rest. This method is based essentially on the fact that the form of the differential equation for the velocity potential is invariant with regard to conformal transformation of the meridian plane. By means of the conformal transformation of the meridian profile into a circle a system of orthogonal curvilinear coo… more
Date: May 18, 1942
Creator: Kaplan, Carl
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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