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Investigation of damping liquids for aircraft instruments

Description: "This report covers the results of an investigation carried on at the Bureau of Standards under a research authorization from, and with the financial assistance of, the National Advisory Committee for Aeronautics. The choice of a damping liquid for aircraft instruments is difficult owing to the range of temperature at which aircraft operate. Temperature changes affect the viscosity tremendously. The investigation was undertaken with the object of finding liquids of various viscosities otherwise… more
Date: May 16, 1928
Creator: Keulegan, G. H.
Partner: UNT Libraries Government Documents Department
open access

Experimental determination of jet boundary corrections for airfoil tests in four open wind tunnel jets of different shapes

Description: "This experimental investigation was conducted primarily for the purpose of obtaining a method of correcting to free air conditions the results of airfoil force tests in four open wind tunnel jets of different shapes. Tests were also made to determine whether the jet boundaries had any appreciable effect on the pitching moments of a complete airplane model. Satisfactory corrections for the effect of the boundaries of the various jets were obtained for all the airfoils tested, the span of the la… more
Date: April 16, 1930
Creator: Knight, Montgomery & Harris, Thomas A.
Partner: UNT Libraries Government Documents Department
open access

A method for computing leading-edge loads

Description: From Summary: "In this report a formula is developed that enables the determination of the proper design load for the portion of the wing forward of the front spar. The formula is inherently rational in concept, as it takes into account the most important variables that affect the leading-edge load, although theoretical rigor has been sacrificed for simplicity and ease of application. Some empirical corrections, based on pressure distribution measurements on the PW-9 and M-3 airplanes have been… more
Date: January 16, 1931
Creator: Rhode, Richard V. & Pearson, Henry A.
Partner: UNT Libraries Government Documents Department
open access

The effect of area aspect ratio on the yawing moments of rudders at large angles of pitch on three fuselages

Description: This reports presents the results of measurements made of yawing moments produced by rudder displacement for seven rudders mounted on each of three fuselages at angles of pitch of 0 degree, 8 degrees, 12 degrees, 20 degrees, 30 degrees and 40 degrees. The dimensions of the rudders were selected to cover the range of areas and aspect ratios commonly used, while the ratios of rudder area to fin area and of rudder chord to fin chord were kept approximately constant. An important result of the meas… more
Date: May 16, 1932
Creator: Dryden, Hugh L. & Monish, B. H.
Partner: UNT Libraries Government Documents Department
open access

Spinning characteristics of the XN2Y-1 airplane obtained from the spinning balance and compared with results from the spinning tunnel and from flight tests

Description: Report presents the results of tests of a 1/10-scale model of the XN2Y-1 airplane tested in the NACA 5-foot vertical wind tunnel in which the six components of forces and moments were measured. The model was tested in 17 attitudes in which the full-scale airplane had been observed to spin, in order to determine the effects of scale, tunnel, and interference. In addition, a series of tests was made to cover the range of angles of attack, angles of sideslip, rates of rotation, and control setting… more
Date: April 16, 1937
Creator: Bamber, M. J. & House, R. O.
Partner: UNT Libraries Government Documents Department
open access

Preignition characteristics of several fuels under simulated engine conditions

Description: "The preignition characteristics of a number of fuels have been studied under conditions similar to those encountered in an engine. These conditions were simulated by suddenly compressing a fuel-air mixture in contact with an electrically heated hot spot in the cylinder head of the NACA combustion apparatus. Schlieren photographs and indicator cards were taken of the burning, and the hot-spot temperatures necessary to cause ignition under various conditions were determined" (p. 121).
Date: September 16, 1940
Creator: Spencer, R. C.
Partner: UNT Libraries Government Documents Department
open access

Nonstationary flow about a wing-aileron-tab combination including aerodynamic balance

Description: This paper presents a continuation of the work published in Technical Report no. 496. The results of that paper have been extended to include the effect of aerodynamic balance and the effect of a tab added to the aileron. The aerodynamic coefficients are presented in a form convenient for application to the flutter problem.
Date: December 16, 1941
Creator: Theodorsen, Theodore & Garrick, I. E.
Partner: UNT Libraries Government Documents Department
open access

A Method for Determining the Camber and Twist of a Surface to Support a Given Distribution of Lift, With Applications to the Load Over a Sweptback Wing

Description: "A graphical method is described for finding the shape (camber and twist) of an airfoil having an arbitrary distribution of lift. The method consists in replacing the lifting surface and its wake with an equivalent arrangement of vortices and in finding the associated vertical velocities. By division of the vortex pattern into circular strips concentric about the downwash point instead of into the usual rectangular strips, the lifting surface is reduced for each downwash point to an equivalent … more
Date: May 16, 1942
Creator: Cohen, Doris
Partner: UNT Libraries Government Documents Department
open access

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.
Partner: UNT Libraries Government Documents Department
open access

Effect of Compressibility at High Subsonic Velocities on the Lifting Force Acting on an Elliptic Cylinder

Description: An extended form of the Ackeret iteration method, applicable to arbitrary profiles, is utilized to calculate the compressible flow at high subsonic velocities past an elliptic cylinder. The angle of attack to the direction of the undisturbed stream is small and the circulation is fixed by the Kutta condition at the trailing end of the major axis. The expression for the lifting force on the elliptic cylinder is derived and shows a first-step improvement of the Prandtl-Glauert rule. It is further… more
Date: May 16, 1946
Creator: Kaplan, Carl
Partner: UNT Libraries Government Documents Department
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A Theoretical Investigation of Hydrodynamic Impact Loads on Scalloped-Bottom Seaplanes and Comparisons With Experiment

Description: "An analytical method is presented for calculating the hydrodynamic impact loads and motions experienced by seaplane floats and hulls with scalloped (fluted) bottoms. The analysis treats vertical impact at zero trim in addition to the more general problem of the step impact of a seaplane at positive trim where the flight path is oblique to the keel and to the water surface. Also considered are the transformations required to represent impacts into waves" (p. 109).
Date: April 16, 1947
Creator: Milwitzky, Benjamin
Partner: UNT Libraries Government Documents Department
open access

On Reflection of Shock Waves from Boundary Layers

Description: Measurements are presented at Mach numbers from about 1.3 to 1.5 of reflection characteristics and the relative upstream influence of shock waves impinging on a flat surface with both laminar and turbulent boundary layers. The difference between impulse and step waves is discussed and their interaction with the boundary layer is compared. General considerations on the experimental production of shock waves from wedges and cones and examples of reflection of shock waves from supersonic shear lay… more
Date: August 16, 1949
Creator: Liepmann, H. W.; Roshko, A. & Dhawan, S.
Partner: UNT Libraries Government Documents Department
open access

A Lift-Cancellation Technique in Linearized Supersonic-Wing Theory

Description: "A lift-cancellation technique is presented for determining load distributions on thin wings at supersonic speeds. The loading on a wing having a prescribed plan form is expressed as the loading of a known related wing (such as a two-dimensional or triangular wing) minus the loading of an appropriate cancellation wing. The lift-cancellation technique can be used to find the loading on a large variety of wings. Applications to swept wings having curvilinear plan forms and to wings having reentra… more
Date: January 16, 1950
Creator: Mirels, Harold
Partner: UNT Libraries Government Documents Department
open access

Inelastic Column Behavior

Description: The significant findings of a theoretical study of column behavior in the plastic stress range are presented. When the behavior of a straight column is regarded as the limiting behavior of an imperfect column as the initial imperfection (lack of straightness) approaches zero, the departure from the straight configuration occurs at the tangent-modulus load. Without such a concept of the behavior of a straight column, one is led to the unrealistic conclusion that lateral deflection of the column … more
Date: October 16, 1950
Creator: Duberg, John E. & Wilder, Thomas W., III
Partner: UNT Libraries Government Documents Department
open access

Integrals and Integral Equations in Linearized Wing Theory

Description: "The formulas of subsonic and supersonic wing theory for source, doublet, and vortex distributions are reviewed and a systematic presentation is provided which relates these distributions to the pressure and to the vertical induced velocity in the plane of the wing. It is shown that care must be used in treating the singularities involved in the analysis and that the order of integration is not always reversible. Concepts suggested by the irreversibility of order of integration are shown to be … more
Date: October 16, 1950
Creator: Lomax, Harvard; Heaslet, Max A. & Fuller, Franklyn B.
Partner: UNT Libraries Government Documents Department
open access

Study of inadvertent speed increases in transport operation

Description: From Summary: "Some factors relating to inadvertent speed and Mach number increases in transport operation are discussed with the object of indicating the manner in which they might vary with different qualities of the airplane and the minimum margins required to guard against reaching unsafe values. The speed increments and the margins required under several assumed conditions are investigated. The results indicate that, on a percentage basis, smaller margins should be required of high-speed a… more
Date: November 16, 1951
Creator: Pearson, Henry A.
Partner: UNT Libraries Government Documents Department
open access

On the Application of Transonic Similarity Rules to Wings of Finite Span

Description: "The transonic aerodynamic characteristics of wings of finite span are discussed from the point of view of a unified small perturbation theory for subsonic, transonic, and supersonic flows about thin wings. This approach avoids certain ambiguities which appear if one studies transonic flows by means of equations derived under the more restrictive assumption that the local velocities are everywhere close to sonic velocity. The relation between the two methods of analysis of transonic flow is exa… more
Date: December 16, 1952
Creator: Spreiter, John R.
Partner: UNT Libraries Government Documents Department
open access

An investigation of the effects of heat transfer on boundary-layer transition on a parabolic body of revolution (NACA RM-10) at a Mach number of 1.61

Description: Report presents the results of an investigation conducted to determine the effects of heat transfer on boundary-layer transition on a parabolic body of revolution (NACA rm-10 without fins) at Mach number of 1.61 and over a Reynolds number range from 2.5 x 10(6) to 35 x 10(6). The maximum cooling of the model used in these tests corresponded to a temperature ratio (ratio of model-surface temperature to free-stream temperature) of 1.12, a value somewhat higher than the theoretical value required … more
Date: February 16, 1953
Creator: Czarnecki, K. R. & Sinclair, Archibald R.
Partner: UNT Libraries Government Documents Department
open access

The zero-lift drag of a slender body of revolution (NACA RM-10 research model) as determined from tests in several wind tunnels and in flight at supersonic speeds

Description: From Summary: "The results of tests of a slender body of revolution designated the NACA rm-10 have been compiled from various NACA test facilities. Zero-lift drag data are presented for a Reynolds number range from about 1 x 10(6) to 40 x 10(6) from several wind tunnels and from about 12 x 10(6) to 140 x 10(6) from free-flight tests. The Mach numbers covered include 1.5 to 2.4 for the wind-tunnel data and 0.85 to 2.5 for the flight results. The wind tunnel models were tested with and without 60… more
Date: April 16, 1953
Creator: Evans, Albert J.
Partner: UNT Libraries Government Documents Department
open access

Summary of scale-model thrust-reverser investigation

Description: An investigation was undertaken to determine the characteristics of several basic types of thrust-reverser. Models of three types, target, tailpipe cascade, and ring cascade, were tested with unheated air. The effects of design variables on reverse-thrust performance, reversed-flow boundaries, and thrust modulation characteristics were determined.
Date: December 16, 1955
Creator: Povolny, John H.; Steffen, Fred W. & McArdle, Jack G.
Partner: UNT Libraries Government Documents Department
open access

Comparison of several methods for obtaining the time response of linear systems to either a unit impulse or arbitrary input from frequency-response data

Description: From Summary: "Several methods of obtaining the time response of Linear systems to either a unit impulse or an arbitrary input from frequency-response data are described and compared. Comparisons indicate that all the methods give good accuracy when applied to a second-order system; the main difference is the required computing time. The methods generally classified as inverse Laplace transform methods were found to be most effective in determining the response to a unit impulse from frequency-… more
Date: March 16, 1956
Creator: Donegan, James J. & Huss, Carl R.
Partner: UNT Libraries Government Documents Department
open access

A special method for finding body distortions that reduce the wave drag of wing and body combinations at supersonic speeds

Description: For a given wing and supersonic Mach number, the problem of shaping an adjoining fuselage so that the combination will have a low wave drag is considered. Only fuselages that can be simulated by singularities (multipoles) distributed along the body axis are studied. However, the optimum variations of such singularities are completely specified in terms of the given wing geometry. An application is made to an elliptic wing having a biconvex section, a thickness-chord ratio equal to 0.05 at the r… more
Date: May 16, 1956
Creator: Lomax, Harvard & Heaslet, Max A.
Partner: UNT Libraries Government Documents Department
open access

Ditching investigations of dynamic models and effects of design parameters on ditching characteristics

Description: From Summary: "Data from ditching investigations conducted at the Langley Aeronautical Laboratory with dynamic scale models of various airplanes are presented in the form of tables. The effects of design parameters on the ditching characteristics of airplanes, based on scale-model investigations and on reports of full-scale ditchings, are discussed. Various ditching aids are also discussed as a means of improving ditching behavior."
Date: November 16, 1956
Creator: Fisher, Lloyd J. & Hoffman, Edward L.
Partner: UNT Libraries Government Documents Department
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