# Search Results

## 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.
Partner: UNT Libraries Government Documents Department

## Elements of the Wing Section Theory and of the Wing Theory

Description: Results are presented of the theory of wings and of wing sections which are of immediate practical value. They are proven and demonstrated by the use of the simple conceptions of kinetic energy and momentum only.
Date: December 1, 1979
Creator: Munk, Max M.
Partner: UNT Libraries Government Documents Department

## 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 and oblate spheroid, and the circular disk. The velocity and pressure in an oblique flow are examined.
Date: December 1, 1979
Creator: Zahm, A. F.
Partner: UNT Libraries Government Documents Department

## 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 for the latter forms. In some useful cases experimental pressures are plotted for comparison with theoretical. The pressure, and thence the zonal force and moment, on hulls in plane curvilinear flight are calculated. General equations for the resultant fluid forces and moments on trisymmetrical bodies moving through a perfect fluid are derived. Formulas for potential coefficients and inertia coefficients for an ellipsoid and its limiting forms are presented.
Date: December 1, 1979
Creator: Zahm, A. F.
Partner: UNT Libraries Government Documents Department

## 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 of the general theory of arbitrary sections, permitting a clearer perspective of the entire field. The method which permits the determination of the velocity at any point of an arbitrary section and the associated lift and moments is described. The method is also discussed in terms for developing new shapes of preassigned aerodynamical properties.
Date: December 1, 1979
Creator: Theodorsen, T. & Garrick, I. E.
Partner: UNT Libraries Government Documents Department

## 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. The air forces being known, the mechanism of aerodynamic instability was analyzed. An exact solution, involving potential flow and the adoption of the Kutta condition, was derived. The solution is of a simple form and is expressed by means of an auxiliary parameter k. The flutter velocity, treated as the unknown quantity, was determined as a function of a certain ratio of the frequencies in the separate degrees of freedom for any magnitudes and combinations of the airfoil-aileron parameters.
Date: December 1, 1979
Creator: Theodorsen, Theodore
Partner: UNT Libraries Government Documents Department

## Graphic Construction of Joukowski Wings

Description: A plot of the cross sectional outline of a Joukowski wing is presented.
Date: December 1, 1979
Creator: Trefftz, E.
Partner: UNT Libraries Government Documents Department

## 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 shape of the hull is changed, being 0.637 for a circular or elliptic disk, 0.5 for a sphere, and about 0.25 for a spheroid of fineness ratio. The case of rotation of an airship hull is investigated and a coefficient is defined with the same advantages as the corresponding coefficient for rectilinear motion.
Date: December 1979
Creator: Bateman, H.
Partner: UNT Libraries Government Documents Department

## 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: December 1, 1979
Creator: Munk, M. M.
Partner: UNT Libraries Government Documents Department

## Remarks on the Pressure Distribution over the Surface of an Ellipsoid, Moving Translationally Through a Perfect Fluid

Description: The pressure distribution over ellipsoids when in translatory motion through a perfect fluid is calculated. A method to determine the magnitude of the velocity and of the pressure at each point of the surface of an ellipsoid of rotation is described.
Date: December 1, 1979
Creator: Munk, Max M.
Partner: UNT Libraries Government Documents Department

## 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, M. M.
Partner: UNT Libraries Government Documents Department

## 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. Illustrations of these formulae as applied to the acquisition of transformations from a known simple flow to new types of flow for other boundaries are given. Theoretical and experimental investigations of models of airship bodies are presented.
Date: 1979?~
Creator: Prandtl, L.
Partner: UNT Libraries Government Documents Department

## An approximate spin design criterion for monoplanes, 1 May 1939

Description: An approximate empirical criterion, based on the projected side area and the mass distribution of the airplane, was formulated. The British results were analyzed and applied to American designs. A simpler design criterion, based solely on the type and the dimensions of the tail, was developed; it is useful in a rapid estimation of whether a new design is likely to comply with the minimum requirements for safety in spinning.
Date: January 1, 1976
Creator: Seidman, O. & Donlan, C. J.
Partner: UNT Libraries Government Documents Department

## Spin tests of a low-wing monoplane to investigate scale effect in the model test range, May 1941

Description: Concurrent tests were performed on a 1/16 and a 1/20 scale model (wing spans of 2.64 and 2.11 ft. respectively) of a modern low wing monoplane in the NACA 15 foot free-spinning wind tunnel. Results are presented in the form of charts that afford a direct comparison between the spins of the two models for a number of different conditions. Qualitatively, the same characteristic effects of control disposition, mass distribution, and dimensional modifications were indicated by both models. Quantitatively, the number of turns for recover and the steady spin parameters, with the exception of the inclination of the wing to the horizontal, were usually in good agreement.
Date: January 1, 1976
Creator: Donlan, C. J.
Partner: UNT Libraries Government Documents Department

## Smoking characteristics of various fuels as determined by open-cup and laboratory-burner smoke tests

Description: Report discussing tests in a combustion chamber to obtain smoking characteristics data on a variety of hydrocarbon fuels. Details about the smoking tendencies and burning rates of the fuels in uncontrolled and controlled tests are provided.
Date: {1945-06, 1945-09}
Creator: Ebersole, Earl R. & Barnett, Henry C.
Partner: UNT Libraries Government Documents Department

## Spin-Tunnel Investigation of a 1/28-Scale Model of a Subsonic Attack Airplane

Description: An investigation has been made of a 1/28-scale model of the Grumman A-6A airplane in the Langley spin tunnel. The erect spin and recovery characteristics of the model were determined for the flight design gross weight loading and for a loading with full internal fuel and empty external wing fuel tanks. The effects of extending slats and deflecting flaps were investigated. Inverted-spin and recovery characteristics of the model were determined for the flight design gross weight loading. The size of the spin-recovery tail parachute necessary to insure satisfactory spin-recovery was determined, and the effect of firing wing-mounded rockets during spins was investigated.
Date: July 1964
Creator: Lee, Henry A. & Healy, Frederick M.
Partner: UNT Libraries Government Documents Department

## Spin Tunnel Investigation of a 1/30 Scale Model of the North American A-5A Airplane

Description: An investigation has been made in the Langley spin tunnel to determine the erect and inverted spin and recovery characteristics of a 1/30-scale dynamic model of the North American A-5A airplane. Tests were made for the basic flight design loading with the center of gravity at 30-percent mean aerodynamic chord and also for a forward position and a rearward position with the center of gravity at 26-percent and 40-percent mean aerodynamic chord, respectively. Tests were also made to determine the effect of full external wing tanks on both wings, and of an asymmetrical condition when only one full tank is carried.
Date: June 1964
Creator: Lee, Henry A.
Partner: UNT Libraries Government Documents Department

## Some Research on the Lift and Stability of Wing-Body Combinations

Description: The present paper summarizes and correlates broadly some of the research results applicable to fin-stabilized ammunition. The discussion and correlation are intended to be comprehensive, rather than detailed, in order to show general trends over the Mach number range up to 7.0. Some discussion of wings, bodies, and wing-body interference is presented, and a list of 179 papers containing further information is included. The present paper is intended to serve more as a bibliography and source of reference material than as a direct source of design information.
Date: July 2, 1959
Creator: Purser, Paul E. & Fields, E. M.
Partner: UNT Libraries Government Documents Department

## An analytical evaluation of the effects of an aerodynamic modification and of stability augmenters on the pitch behavior and probable pilot opinion of two current fighter airplanes

Description: No Description Available.
Date: April 21, 1959
Creator: Sadoff, Melvin & Stewart, John D
Partner: UNT Libraries Government Documents Department

## Effects of components and various modifications on the drag and the static stability and control characteristics of a 42 deg swept-wing fighter-airplane model at Mach numbers of 1.60 to 2.50

Description: Wind tunnel testing of swept wing fighter aircraft model for determining drag and static longitudinal and lateral stability and control characteristics.
Date: April 15, 1959
Creator: Church, J. D.
Partner: UNT Libraries Government Documents Department

## Boundary-layer Displacement Effects in Air at Mach Numbers of 6.8 and 9.6

Description: Boundary layer displacement effects in air at mach 6.8 and 9.6.
Date: January 1, 1959
Creator: Bertram, M. H.
Partner: UNT Libraries Government Documents Department

## Forty-Fourth Annual Report of the National Advisory Committee for Aeronautics Administrative Report Including Technical Reports Nos. 1342 to 1392

Description: In accordance with act of Congress, approved March 3, 1915, as amended (U.S.C., title 50, .sw 151), which established the National Advisory Committee for Aeronautics, the Committee submits its Forty-fourth Annual Report for the fiscal year 1958. This is the Committee's final report to the Congress. The National Aeronautics and Space Act of 1958 (Public Law 85-568) provides in section 301 that the NACA "shall cease to exist" and "all functions, powers, duties, and obligations, and all real and personal property, personnel (other than members of the Committee), funds, and records of the NACA shall be transferred to the National Aeronautics and Space Administration. The aforesaid act provides that "this section shall take effect 90 days after the date of the enactment of this act, or on any earlier date on which the Administrator shall determining and announce by proclamation published in the Federal Register, that the Administration has been organized and is prepared to discharge the duties and exercise the power conferred upon it by this act." The Administrator, Hon. T. Keith Glennan has advised the Committee of his intention to issue such proclamation, effective October 1,1958.
Date: 1959
Partner: UNT Libraries Government Documents Department

## One-dimensional flows of an imperfect diatomic gas

Description: With the assumptions that Berthelot's equation of state accounts for molecular size and intermolecular force effects, and that changes in the vibrational heat capacities are given by a Planck term, expressions are developed for analyzing one-dimensional flows of a diatomic gas. The special cases of flow through normal and oblique shocks in free air at sea level are investigated. It is found that up to a Mach number 10 pressure ratio across a normal shock differs by less than 6 percent from its ideal gas value; whereas at Mach numbers above 4 the temperature rise is considerable below and hence the density rise is well above that predicted assuming ideal gas behavior. It is further shown that only the caloric imperfection in air has an appreciable effect on the pressures developed in the shock process considered. The effects of gaseous imperfections on oblique shock-flows are studied from the standpoint of their influence on the life and pressure drag of a flat plate operating at Mach numbers of 10 and 20. The influence is found to be small. (author).
Date: January 1, 1959
Partner: UNT Libraries Government Documents Department

## Combustor performance with various hydrogen-oxygen injection methods in a 200-pound-thrust rocket engine

Description: No Description Available.
Date: September 30, 1958
Creator: Heidmann, M F & Baker, Louis, Jr
Partner: UNT Libraries Government Documents Department