National Advisory Committee for Aeronautics (NACA) - 122 Matching Results

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Aerial navigation by dead reckoning

Description: Report discussing the problem to be solved, as presented to the pilot or observer of an aircraft, is as follows: The aircraft starting from A must land at B, the only data being the speed of the airplane, the altitude and the orientation D of the course. The above data would be amply sufficient, were it not for the fact that the airplane is constantly subjected to a wind of variable direction and strength.
Date: July 1922
Creator: Maffert, Pierre
Partner: UNT Libraries Government Documents Department

Aero dopes and varnishes

Description: Report discussing before proceeding to discuss the preparation of dope solutions, it will be necessary to consider some of the essential properties which should be possessed of a dope film, deposited in and on the surface of an aero fabric. The first is that it should tighten the material and second it should withstand weathering.
Date: July 1927
Creator: Britton, H T S
Partner: UNT Libraries Government Documents Department

Aerodynamic Research on Fuselages with Rectangular Cross Section

Description: The influence of the deflected flow caused by the fuselage (especially by unsymmetrical attitudes) on the lift and the rolling moment due to sideslip has been discussed for infinitely long fuselages with circular and elliptical cross section. The aim of this work is to add rectangular cross sections and, primarily, to give a principle by which one can get practically usable contours through simple conformal mapping. In a few examples, the velocity field in the wing region and the induced flow produced are calculated and are compared with corresponding results from elliptical and strictly rectangular cross sections.
Date: July 1958
Creator: Maruhn, K.
Partner: UNT Libraries Government Documents Department

Aerodynamics and ballistics

Description: Ballistics is a science hundreds of years old and this report is an attempt to show how these older principles can be used in the newer science of aerodynamics.
Date: July 1922
Creator: Burzio, Filippo
Partner: UNT Libraries Government Documents Department

Air admixture to exhaust jets

Description: From Introduction: "The problem of thrust increase for jet engines by air mixture to the exhaust jet was introduced into aviation techniques by the suggestions of Melot (ref.1). Due to a too general interpretation of several theoretical investigations of A. Busemann (ref.2), so far no practical use has been made of these suggestions. The following considerations show that, in the case of low-pressure mixing according to Melot's suggestions, probably no thrust increase of technical significance will occur for the flight speeds of interest (however, the low-pressure mixture is highly promising for ground test setups and for special power plants of relatively slow sea and land vehicles."
Date: July 1953
Creator: Sanger, Eugen
Partner: UNT Libraries Government Documents Department

Air forces and air-force moments at large angles of attack and how they are affected by the shape of the wing

Description: From Summary: "The present report is, in the first place, a compilation of the test results now available from wing tests up to angles of attack 90^o. Reports are also given of tests with monoplane and auxiliary wings in the Gottingen wind tunnel for the purpose of plotting a steadily rising curve of the normal force as a foundation of the angle of attack."
Date: July 1930
Creator: Fuchs, Richard & Schmidt, Wilhelm
Partner: UNT Libraries Government Documents Department

Air-water analogy and the study of hydraulic models

Description: From Summary: "The author first sets forth some observations about the theory of models. Then he established certain general criteria for the construction of dynamically similar models in water and in air, through reference to the perfect fluid equations and to the ones pertaining to viscous flow. It is, in addition, pointed out that there are more cases in which the analogy is possible than is commonly supposed."
Date: July 1, 1953
Creator: Supino, Giulio
Partner: UNT Libraries Government Documents Department

Airplane landing gear

Description: This report presents an investigation of the design and construction of various types of landing gears. Some of the items discussed include: chassises, wheels, shock absorbers (rubber disk and rubber cord), as well as oleopneumatic shock absorbers. Various types of landing gears are also discussed such as the Messier, Bendix, Vickers, and Bleriot.
Date: July 1931
Creator: Maiorca, Salvatore
Partner: UNT Libraries Government Documents Department

Airplane stability calculations and their verification by flight tests

Description: For some time, the designers of airplanes have begun to occupy themselves with the question of longitudinal stability. In their quest to simplify calculation and data collection, the designers have attached the greatest importance to the coefficient of initial longitudinal stability. In this study a diagram was constructed from the data of the tunnel tests, which depends neither on the position of the center of gravity nor of the angle of deflection of the elevators. This diagram is constructed by means of straight lines drawn through the metacenters of the complete airplane, in a direction parallel to the tangents to the polar of the airplane relative to a system of axes fixed with reference to the airplane.
Date: July 1, 1922
Creator: Rota, Augusto
Partner: UNT Libraries Government Documents Department

The Analysis of Aircraft Structures as Space Frameworks. Method Based on the Forces in the Longitudinal Members

Description: The following examples do not take up the discussion of viewpoints to be heeded in determining the design of a framework for given external conditions. Rather they are methods for determining the forces in airplane fuselages and wings, though similar considerations are applied to certain simple cases of a different kind. The object of this treatise is to summarize and amplify these considerations from definite viewpoints.
Date: July 1, 1929
Creator: Wagner, Herbert
Partner: UNT Libraries Government Documents Department

Analytical Treatment of Normal Condensation Shock

Description: The condensation of water vapor in an air consequences: acquisition of heat (liberated heat vaporization; loss of mass on the part of the flowing gas (water vapor is converted to liquid); change in the specific gas constants and of the ratio k of the specific heats (caused by change of gas composition). A discontinuous change of state is therefore connected with the condensation; schlieren photographs of supersonic flows in two-dimensional Laval nozzles show two intersecting oblique shock fronts that in the case of high humidities may merge near the point of intersection into one normal shock front.
Date: July 1, 1947
Creator: Heybey
Partner: UNT Libraries Government Documents Department

The apparent width of the plate in compression

Description: This report discusses an investigation that treats the load capacity of a rectangular plate stressed in compression on one direction (x) beyond the buckling limit and the plate is rotatable (i.e., free from moments) supported at all four sides by bending-resistant beams.
Date: July 1937
Creator: Marguerre, Karl
Partner: UNT Libraries Government Documents Department

The "Autogiro"

Description: For the first time in the world, a flying machine, heavier than the air and distinct from the airplane, has completed a circuit of four kilometers (nearly 2.5 miles) at a height of more than 25 meters (82 feet) above the ground.
Date: July 1923
Creator: Moreno-Caracciolo, M
Partner: UNT Libraries Government Documents Department

Balloon flight and atmospheric electricity

Description: The air is known to be charged with electricity (chiefly positive) with reference to the earth, so that its potential increases with the altitude and the difference in potential between two points in the same vertical line, divided by the distance between them, gives a value called the "potential gradient," which may vary greatly with the altitude, the nature of the ground and the atmospheric conditions.
Date: July 1, 1924
Creator: Herrera, Emilio
Partner: UNT Libraries Government Documents Department

Behavior of a plate strip under shear and compressive stresses beyond the buckling limit

Description: The present report is an extension of previous theoretical investigations on the elastic behavior of a plate under compression and shear in the region above the critical. The main object is the clarification of the behavior immediately above the buckling limit since no theoretical expressions for this range have thus far been found and since experimentally, too, any degree of regularity in the behavior of the plate in the range between the critical load and about three to four times the critical, is discernible only with difficulty.
Date: July 1, 1938
Creator: Kromm, A & Marguerre, K
Partner: UNT Libraries Government Documents Department

Calculation of potential flow past airship bodies in yaw

Description: An outline of Von Karman's method of computing the potential flow of airships in yaw by means of partially constant dipolar superposition on the axis of the body is followed by several considerations for beginning and end of the superposition. Then this method is improved by postulating a continuous, in part linearly variable dipolar superposition on the axis. The second main part of the report brings the calculation of the potential flow by means of sources and sinks, arranged on the surface of the airship body. The integral equation which must satisfy this surface superposition is posed, and the core reduced to functions developed from whole elliptical normal integrals. The functions are shown diagrammatically. The integration is resolvable by iteration. The consequence of the method is good. The formulas for computing the velocity on the surface and of the potential for any point conclude the report.
Date: July 1, 1932
Creator: Lotz, I
Partner: UNT Libraries Government Documents Department

Calculation of Pressure Distribution on Airship Hulls

Description: These calculations were based on the shape of the ZR III, with the following simplifications: cars, fins, and rudders removed; all cross sections replaced by equivalent circular cross sections. Under these assumptions the pressure distribution was calculated for the following cases: symmetrical case, or flow parallel to the axis; unsymmetrical case, or flow at an angle to the axis. In both cases the simple potential flow first forms the basis for the determination of the pressure distribution.
Date: July 1, 1930
Creator: Von Karman, Theodor
Partner: UNT Libraries Government Documents Department

Calculation of the Pressure Distribution on Bodies of Revolution in the Subsonic Flow of a Gas, Part 1, Axially Symmetrical Flow

Description: The present report concerns a method of computing the velocity and pressure distributions on bodies of revolution in axially symmetrical flow in the subsonic range. The differential equation for the velocity potential Phi of a compressible fluid motion is linearized tn the conventional manner, and then put in the form Delta(Phi) = 0 by affine transformation. The quantity Phi represents the velocity potential of a fictitious incompressible flow, for which a constant superposition of sources by sections is secured by a method patterned after von Karman which must comply with the boundary condition delta(phi)/delta(n) = 0 at the originally specified contour. This requirement yields for the "pseudo-stream function" psi a differential equation which must be fulfilled for as many points on the contour as source lengths are assumed. In this manner, the problem of defining the still unknown source intensities is reduced to the solution of an inhomogeneous equation system. The pressure distribution is then determined with the aid of Bernoulli's equation and adiabatic equation of state. Lastly, the pressure distributions in compressible and incompressible medium are compared on a model problem.
Date: July 1, 1947
Creator: Bilharz, Herbert & Hoelder, Ernst
Partner: UNT Libraries Government Documents Department

Charts for checking the stability of compression members in trusses

Description: The present report contains a set of charts developed for computing the fixity effect on a compression member in a truss through its adjacent members, the amount of fixity being considered variable with the particular total truss load. The use of the charts is illustrated on two- and three-bay systems, as well as on a triangular truss.
Date: July 1, 1936
Creator: Borkmann, K
Partner: UNT Libraries Government Documents Department

Computation of cantilever airplane wings

Description: The purpose of this treatise is, first of all, the determination of the effect of variously loaded spars on one another, since the neglect of this effect would present an economically very unfavorable computation method. The system of spars and cross-bars alone (whether solid or built-up) does not matter at first, the original assumption being that the spars are rigidly braced by the cross-bars.
Date: July 1, 1925
Creator: Thalau, K
Partner: UNT Libraries Government Documents Department