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An Investigation of Sheet-Stiffener Panels Subjected to Compression Loads With Particular Reference to Torsionally Weak Stiffeners

Description: "A total of 183 panel specimens of 24ST aluminum alloy with nominal thickness of 0.020, and 0.040 inch with extruded bulb-angle sections of 12 shapes spaced 4 and 5 inches as stiffeners were tested to obtain the buckling stress and the amplitude of the maximum wave when buckled. Bulb angles from 3 to 27 1/2 inches long were tested as pin-end columns. The experimental data are presented as stress-strain and column curves and in tabular form" (p. 1).
Date: February 1940
Creator: Dunn, Louis G.
Partner: UNT Libraries Government Documents Department
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Measured Moments of Inertia of 32 Airplanes

Description: "A compilation of the experimentally determined moments of inertia of 32 airplanes is presented. The measurements were obtained at the laboratories of the NACA by means of a pendulum method. The airplanes tested are representative of several types of aircraft of gross weight less than 10,000 pounds. The results are presented in coefficient as well as in dimensional form. An elementary analysis of the data disclosed the possibility of grouping the results according to wing type of the airplane, … more
Date: October 1940
Creator: Gracey, William
Partner: UNT Libraries Government Documents Department
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Measurement of the Forces Acting on Gliders in Towed Flight

Description: "The magnitude, the direction, and the fluctuations of tow forces exerted upon gliders by towing them aloft behind an automobile were measured under a variety of conditions covering a range from gentle to severe types of operation. For these tests, the glider towing force did not exceed 1.6 of the gross weight of the glider. V-G records obtained during the towed-flight period as well as during the subsequent return glide to earth showed accelerations in the range from 3 to -1 g. The results of … more
Date: February 1940
Creator: Klemperer, W. B.
Partner: UNT Libraries Government Documents Department
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An Investigation of the Prevention of Ice on the Airplane Windshield

Description: "An investigation of three methods for the prevention and the removal of ice on an airplane windshield has been completed. The methods were: electric heating; hot-air heating; and an alcohol-dispensing, rotating wiper blade. The results showed that vision through the airplane windshield could be maintained during severe icing conditions by the use of heat" (p. 1).
Date: March 1940
Creator: Rodert, Lewis A.
Partner: UNT Libraries Government Documents Department
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The frequencies of cantilever wings in beam and torsional vibrations

Description: From Summary: "Methods are described for calculating the period and frequency of vibration of cantilever wings and similar structures in which the weight and moment of inertia vary along the span. Both the beam and torsional frequencies may be calculated by these methods. The procedure is illustrated by examples."
Date: January 1940
Creator: Burgess, C. P.
Partner: UNT Libraries Government Documents Department
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Propeller Rotation Noise Due to Torque and Thrust

Description: "Sound pressure of the first four harmonics of rotation from a full-scale two-blade propeller were measured and are compared with values calculated from theory. The comparison is made (1) for the space distribution with constant tip speed and (2) for fixed space angles with variable tip speed. A relation for rotation noise from an element of radius developed by Gutin is given showing the effect of number of blades on the rotation noise" (p. 1).
Date: January 1940
Creator: Deming, Arthur F.
Partner: UNT Libraries Government Documents Department
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Notes on the stalling of vertical tail surfaces and on fin design

Description: From Summary: "A discussion is given of the important aspects of the stalling of vertical tail surfaces. The type of instability encountered is described and the possibilities of inadvertent occurrence are noted. The influence of directional flight tests on the behavior of a airplane when the tail stall takes place is discussed. In this connection, flight tests of a twin-engine airplane in which the vertical fin area was increased are cited."
Date: October 1940
Creator: Thompson, F. L. & Gilruth, R. R.
Partner: UNT Libraries Government Documents Department
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A new method of studying the flow of the water along the bottom of a model of a flying-boat hull

Description: A new method of studying the flow of the water along the bottom of a model of a flying-boat hull is described. In this method, the model is fitted with a transparent bottom and is divided down the center line by a bulkhead. The flow is observed and photographed through one-half of the model by means of the diffused illumination from a battery of lamps contained in the other half of the model. Photographs of the flow, particularly of the changes that occur when the step ventilates, are shown. Th… more
Date: February 1940
Creator: Ward, Kenneth E.
Partner: UNT Libraries Government Documents Department
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A Generalized Vortex Theory of the Screw Propeller and Its Application

Description: "The vortex theory as presented by the author in earlier papers has been extended to permit the solution of the following problems: (1) the investigation of the relation between thrusts and torque distribution and energy loss as given by the induction of helical vortex sheets and by the parasite drag; (2) the checking of the theorem of Betz of the rigidly behaving helical vortex sheet of minimum induced energy loss; (3) the extension of the theory of the screw propeller of minimum energy loss f… more
Date: February 1940
Creator: Reissner, Hans
Partner: UNT Libraries Government Documents Department
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Damping formulas and experimental values of damping in flutter models

Description: The problem of determining values of structural damping for use in flutter calculations is discussed. The concept of equivalent viscous damping is reviewed and its relation to the structural damping coefficient g introduced in NACA Technical Report No. 685 is shown. The theory of normal modes is reviewed and a number of methods are described for separating the motions associated with different modes. Equations are developed for use in evaluating the damping parameters from experimental data. Ex… more
Date: February 1940
Creator: Coleman, Robert P.
Partner: UNT Libraries Government Documents Department
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Wind-tunnel investigation of an NACA 23030 airfoil with various arrangements of slotted flaps

Description: An investigation was made of a large-chord NACA 23030 airfoil with a 40- and a 25.66 percent-chord slotted flap to determine the section aerodynamic characteristics of the airfoil affected by flap chord, slot shape, flap position, and flap deflection. The flap positions for maximum lift, the position for minimum drag at moderate and high lift coefficients, and the complete section aerodynamic characteristics of selected optimum arrangements are given. Envelope polar of various flap arrangements… more
Date: March 1940
Creator: Recant, I. G.
Partner: UNT Libraries Government Documents Department
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The Effects of Piston-Head Shape, Cylinder-Head Shape, and Exhaust Restriction, on the Performance of a Piston-Ported Two-Stroke Cylinder

Description: Report presenting testing of a model of the two-stroke engine described in NACA Technical Note No. 674 for the purpose of observing the scavenging-air flow obtained with various inlet-port arrangements. Three types of cylinder head were tried with the round-edge piston in the engine. Results regarding the effect of port arrangement, pistons, cylinder-head shapes, effect of swirl, and exhaust restrictions are provided.
Date: March 1940
Creator: Rogowski, A. R.; Bouchard, C. L. & Taylor, C. Fayette
Partner: UNT Libraries Government Documents Department
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Wind tunnel tests of an NACA 23021 airfoil equipped with a slotted extensible and a plain extensible flap

Description: "An investigation has been made in the NACA 7- by 10-foot wind tunnel of a large chord NACA 23021 airfoil equipped with two arrangements of a completely extended 15 percent chord extensible flap. One of the flaps had a faired juncture, without a gap; the other was provided with a slot between the trailing edge of the airfoil and the nose of the flap. The results showed that the basic airfoil gave the lowest profile-drag coefficients over the low lift range, the airfoil with the plain extensible… more
Date: November 1940
Creator: Swanson, Robert S. & Harris, Thomas A.
Partner: UNT Libraries Government Documents Department
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A study of unsymmetrical-loading conditions

Description: From Summary: "The force variation along the wing span under combined normal and angular accelerations is considered. Non dimensional curves of section load, shear, and moment are given for: (1) the air load that produces a normal acceleration; (2) the accompanying wing weight and normal inertia loads; (3) aileron and gust air loads that produce angular acceleration; (4) the angular inertia load of the wing. The required aerodynamic load distributions have been obtained by use of wing theory, a… more
Date: April 1940
Creator: Pearson, Henry A.
Partner: UNT Libraries Government Documents Department
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Measurements and Analysis of the Motion of a Canard Airplane Model in Gusts

Description: Report presenting a model of a hypothetical canard airplane, which was designed to be of the same size and general aerodynamic characteristics of a Boeing B-247 airplane in the gust tunnel at one wing loading, one forward speed, one gust velocity, and three gust gradients.
Date: April 1940
Creator: Donely, Philip; Pierce, Harold B. & Pepoon, Philip W.
Partner: UNT Libraries Government Documents Department
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Pressure-distribution investigation on an NACA 0009 airfoil with a 30-percent-chord plain flap and three tabs

Description: From Summary: "Pressure-distribution tests of an NACA 0009 airfoil with a 30-percent-chord plain flap and three plain tabs, having chords 10, 20, and 30 percent of the flap chord, were made. The purpose of these tests was to continue an investigation to supply structural and aerodynamic section data that may be applied to the design of horizontal and vertical tail surfaces. The results are presented as diagrams of resultant pressures and of resultant-pressure increments for the airfoil with the… more
Date: May 1940
Creator: Ames, Milton B., Jr. & Sears, Richard I.
Partner: UNT Libraries Government Documents Department
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A Flight Investigation of Exhaust-Heat De-Icing

Description: The National Advisory Committee for Aeronautics conducted exhaust-heat de-icing tests in flight to provide data needed in the application of this method. The capacity to extract heat from the exhaust gas for de-icing purposes, the quantity of heat required, and other factors were examined. The results indicate that a wing-heating system employing a spanwise exhaust tube within the leading edge of the wing removed 30 to 35 percent of the heat from exhaust gas entering the wing. Data are given fr… more
Date: November 1940
Creator: Rodert, Lewis A. & Jones, Alun R.
Partner: UNT Libraries Government Documents Department
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A Full-Scale Investigation of the Effect of Several Factors on the Shimmy of Cantering Wheels

Description: "A full-scale investigation has been conducted to determine the effect of various factors on the shimmy of castering wheels. The factors considered were the geometric arrangement, the tire types, the variations of load, the spindle moment of inertia, and the tire inflation. A comparison of the results of the present investigation with those calculated from existing theory was made" (p. 1).
Date: April 1940
Creator: Howard, Walter B., Jr.
Partner: UNT Libraries Government Documents Department
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Pressure-distribution investigation of an NACA 0009 airfoil with an 80-percent-chord plain flap and three tabs

Description: Pressure-distribution tests of an NACA 0009 airfoil with an 80-percent-chord plain flap and three plain tabs, having chord of 10, 20, and 30 percent of the flap chord, were made. Section data suitable for application to the design of horizontal and vertical tail surfaces were obtained. Resultant-pressure diagrams for the airfoil with the flap and the 20-percent-chord tab are presented. Plots are also given of increments of normal-force and hinge-moment coefficients for the airfoil, the flap, an… more
Date: May 1940
Creator: Ames, Milton B., Jr. & Sears, Richard I.
Partner: UNT Libraries Government Documents Department
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The Flow of a Compressible Fluid Past a Sphere

Description: "The flow of a compressible fluid past a sphere fixed in a uniform stream is calculated to the third order of approximation by means of the Janzen-Rayleigh method. The velocity and the pressure distribution over the surface of the sphere are computed and the terms involving the fourth power of the Mach number, neglected in Rayleigh's calculation, are shown to be of considerable importance as the local velocity of sound is approached on the sphere. The critical Mach number, that is, the value of… more
Date: May 1940
Creator: Kaplan, Carl
Partner: UNT Libraries Government Documents Department
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Wind tunnel investigation of fuselage stability in yaw with various arrangements of fins

Description: "An investigation was made in the 7-by-10 foot wind tunnel to determine the effects of dorsal-type fins and various arrangements of fins on the aerodynamic characteristics of a streamline circular fuselage. Comparative plots of the aerodynamic characteristics of the fuselage alone and the fuselage with various fin arrangements are given to show their effects on coefficients of yawing moment, drag, and lateral force. Results are also given for one case in which a rear fin on a circular fuselage … more
Date: November 1940
Creator: Hoggard, H. Page, Jr.
Partner: UNT Libraries Government Documents Department
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Wind-tunnel investigation of two airfoils with 25-percent-chord Gwinn and plain flaps

Description: Aerodynamic force tests of an NACA 23018 airfoil with a Gwinn flap having a chord 25 percent of the overall chord and of an NACA 23015 airfoil with a plain flap having a 25-percent chord were conducted to determine the relative merits of the Gwinn and the plain flaps. The tests indicated that, based on speed-range ratios, the plain flap was more effective than the Gwinn flap. At small flap deflections, the plain flap had lower drag coefficients at lift-coefficient values less than 0.70. For lif… more
Date: May 1940
Creator: Ames, Milton B., Jr.
Partner: UNT Libraries Government Documents Department
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Structural Tests of a Stainless Steel Wing Panel by Hydrostatic Loading

Description: Note presenting testing of a simplified type of all-metal wing construction of 18-8, spot-welded except for skin attachment, by means of hydrostatic loading, the wing being proportioned to permit close representation of typical conditions by means of the waterhead. The results showed the possibility of eliminating almost all of the stiffeners from a stressed-skin wing, the possible reduction of weight in a lightly loaded wing and of substantial cost in the construction of any all-metal wing.
Date: November 1940
Creator: Upson, Ralph H.
Partner: UNT Libraries Government Documents Department
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