National Advisory Committee for Aeronautics (NACA) - 1,437 Matching Results

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The aerodynamic aspect of wing-fuselage fillets

Description: Report discussing model tests prove the feasibility of enhancing the aerodynamic qualities of wing-fuselage fillets by appropriate design of fuselage and wing roots. Abrupt changes from maximum fuselage height to wing chord must be avoided and every longitudinal section of fuselage and wing roots must be so faired and arranged as to preserve the original lift distribution of the continuous wing. Adapting the fuselage to the curvilinear circulation of the wing affords further improvement. The polars of such arrangements are almost the same as those of the "wing alone," thus voiding the superiority of the high-wing type airplane known with conventional design.
Date: February 1935
Creator: Muttray, H
Partner: UNT Libraries Government Documents Department

Aerodynamic characteristics of thin empirical profiles and their application to the tail surfaces and ailerons of airplanes

Description: From Introduction: "The increasing use of airplane wings equipped with ailerons and the importance of knowing the aerodynamic characteristics of tail units (empennages) provided with movable parts (rudders and elevators) impart some interest to the so-called "empirical profiles." For this purpose we thought best to employ the method proposed by Munk for the approximate theoretical study of thin, slightly curved profiles, assimilable, from an aerodynamic view-point, to their mean camber line."
Date: December 1928
Creator: Toussaint, A & Carafoli, E
Partner: UNT Libraries Government Documents Department

Aerodynamic computation of gliders

Description: From Introduction: "In the following discussion, a knowledge of the theoretical principles of airplane construction is assumed, as presented in detail by Vogt and Lippisch in Nos. 7 and 10-19 of the 1919 volume of this publication. A few quantities will however be otherwise designated, in accordance with the Gottingen symbols."
Date: September 1922
Creator: Schrenk, M
Partner: UNT Libraries Government Documents Department

Aerodynamic Heat-Power Engine Operating on a Closed Cycle

Description: Hot-air engines with dynamic compressors and turbines offer new prospects of success through utilization of units of high efficiencies and through the employment of modern materials of great strength at high temperature. Particular consideration is given to an aerodynamic prime mover operating on a closed circuit and heated externally. Increase of the pressure level of the circulating air permits a great increase of limit load of the unit. This also affords a possibility of regulation for which the internal efficiency of the unit changes but slightly. The effect of pressure and temperature losses is investigated. A general discussion is given of the experimental installation operating at the Escher Wyss plant in Zurich for a considerable time at high temperatures.
Date: November 1942
Creator: Ackeret, J. & Keller, D. C.
Partner: UNT Libraries Government Documents Department

Aerodynamic laboratory at Cuatro Vientos

Description: This report presents a listing of the many experiments in aerodynamics taking place at Cuatro Vientos. Some of the studies include: testing spheres, in order to determine coefficients; mechanical and chemical tests of materials; and various tests of propeller strength and flexibility.
Date: September 1922
Creator: JUBERA
Partner: UNT Libraries Government Documents Department

Aerodynamic principles of the direct lifting propeller

Description: From Summary: "The purpose of this report is to make the complicated processes on the direct-lift propeller amenable to analysis and observation. This is accomplished by placing the physical phenomena, starting with the most elementary process, in the foreground, while limiting the mathematical treatment to the most essential in view of the fundamental defects of the theorems. Comparison with model experiments supplements and corroborates the theoretical results."
Date: January 1934
Creator: Schrenk, Martin
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

The aerodynamic safety of airplanes

Description: This report presents several hypotheses regarding airplane safety, mainly concerning the nondimensional coefficient of air, speed, acceleration, and wing area on aerodynamic considerations of safety.
Date: September 1932
Creator: Kahn, Louis
Partner: UNT Libraries Government Documents Department

The aerodynamic wind vane and the inherent stability of airplanes

Description: Report discussing the design of the wind vane described rests on the following line of reasoning: An airplane, originally in equilibrium about its C.G. is assumed to be deflected from this position through an angle (delta)i, the variation (delta)i being so sudden that the path of the C.G. and the airplane speed do not change while it is taking place. The aerodynamic forces acting on the wings, tail surfaces, fuselage, etc., which, as a whole, exerted a zero moment (M(sub G) = 0) about the center of gravity at the instant of equilibrium, now exert a moment M(sub G) not equal to 0.
Date: February 1931
Creator: Lapresle, A
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

Aerodynamics of rotating-wing aircraft with blade-pitch control

Description: From Introduction: "In the present report, with the aid of the usual computation methods, a rotor is investigated the pitch of whose blades is capable of being controlled in such a manner that it varies linearly with the flapping angle. To test the effect of this linkage on the aircraft performance, the theory is applied to an illustrative example."
Date: February 1940
Creator: Pfluger, A
Partner: UNT Libraries Government Documents Department

Aerodynamics of the Fuselage

Description: The present report deals with a number of problems, particularly with the interaction of the fuselage with the wing and tail, on the basis of simple calculating method's derived from greatly idealized concepts. For the fuselage alone it affords, in variance with potential theory, a certain frictional lift in yawed flow, which, similar to the lift of a wing of small aspect ratio, is no longer linearly related to the angle of attack. Nevertheless there exists for this frictional lift something like a neutral stability point the position of which on oblong fuselages appears to be associated with the lift increase of the fuselage in proximity to the zero lift, according to the present experiments. The Pitching moments of the fuselage can be determined with comparatively great reliability so far as the flow conditions in the neighborhood of the axis of the fuselage can be approximated if the fuselage were absent, which, in general, is not very difficult. For the unstable contribution of the fuselage to the static longitudinal stability of the airplane it affords comparatively simple formulas, the evaluation of which offers little difficulty. On the engine nacelles there is, in addition a very substantial wing moment contribution induced by the nonuniform distribution of the transverse displacement flow of the nacelle along the wing chord; this also can be represented by a simple formula. A check on a large number of dissimilar aircraft types regarding the unstable fuselage and nacelle moments disclosed an agreement with the wind-tunnel tests, which should be sufficient for practical requirements. The errors remained throughout within the scope of instrumental accuracy.
Date: December 1942
Creator: Multhopp, H.
Partner: UNT Libraries Government Documents Department

Aeroelastic Problems of Airplane Design

Description: The technical memorandum briefly summarizes the growth of interest in aeroelastic phenomena as aircraft speed increased and wing designs changed for faster aircraft. Different types of aircraft vibrations are then introduced, and the mathematical basis for the theory behind them is described. Special attention is given to static oscillations, wing flutter, and the flutter of skin panels. The last section of the memorandum deals with the prevention of flutter by design specifications.
Date: November 1956
Creator: Kuessner, H. G.
Partner: UNT Libraries Government Documents Department

Aeronautic instruments

Description: The development of aeronautic instruments. Vibrations, rapid changes of the conditions of flight and of atmospheric conditions, influence of the air stream all call for particular design and construction of the individual instruments. This is shown by certain examples of individual instruments and of various classes of instruments for measuring pressure, change of altitude, temperature, velocity, inclination and turning or combinations of these.
Date: February 1924
Creator: Koppe, H & Everling, E
Partner: UNT Libraries Government Documents Department

Aeronautic insurance

Description: The problem of insuring the emerging commercial aeronautic industry is detailed. The author also motes that a complete solution cannot be obtained until the necessary statistics are compiled.
Date: March 1922
Creator: Neal, Erik
Partner: UNT Libraries Government Documents Department

Aeronautical education and research at the Swiss Institute of Technology in Zurich

Description: Progress in the scientific and practical fields of aviation has caused the Swiss Institute of Technology to organize lectures and practical training courses in all three branches of aeronautics and to found centers of scientific research, laboratories, etc., in order to supply the government and industries with scientifically and technically trained engineers.
Date: April 1931
Creator: Karner, L & Ackeret, J
Partner: UNT Libraries Government Documents Department