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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.
Item Type: Refine your search to only Report
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.
Item Type: Refine your search to only Report
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.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Strength of Shell and Tubular Spar Wings

Description: The report is a survey of the strength problems arising on shell and tubular spar wings. The treatment of the shell wing strength is primarily confined to those questions which concern the shell wing only; those pertaining to both shell wing and shell body together have already been treated in TM 838. The discussion of stress condition and compressive strength of shell wings and tubular spar wings is prefaced by several considerations concerning the spar and shell design of metal wings from the… more
Date: February 1940
Creator: Ebner, H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Testing of High-Octane Fuels in the Single-Cylinder Airplane Engine

Description: "One of the most important properties of aviation fuels for spark-ignition engines is their knock rating. The CFR engine tests of fuels of 87 octane and above does not always correspond entirely to the actual behavior of these fuels in the airplane engine. A method is therefore developed which, in contrast to the octane number determination, permits a testing of the fuel under various temperatures and fuel mixture conditions. The following reference fuels were employed: 1) Primary fuels; isooct… more
Date: February 1940
Creator: Seeber, Fritz
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Wind-Tunnel Tests of the NACA 45-125 Airfoil: A Thick Airfoil for High-Speed Airplanes

Description: Report discussing an investigation of the pressure distribution, profile drag, and location of transition for a NACA 45-125 airfoil for the purpose of aiding in the development of a thick wing for high-speed airplanes. The critical speed, pressure distribution, and drag of the airfoil are detailed.
Date: February 1940
Creator: Delano, James B.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Flow coefficients of monosleeve valves

Description: The flow coefficients of the intake and the exhaust ports of a sleeve-valve cylinder were measured by attaching the cylinder to a large tank and measuring the changes in pressure and temperature in the tank that were caused by short periods of air flow through the valve ports. The derivation of the equations on which the flow coefficients are based is given. The distribution of total pressure in the arms of the sleeve-valve intake manifold was measured. The arms are found to have as little as 7… more
Date: February 8, 1940
Creator: Waldron, C. D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Tensile Elastic Properties of Typical Stainless Steels and Nonferrous Metals as Affected by Plastic Deformation and by Heat Treatment

Description: A general discussion is given of the relationships between stress, strain, and permanent set. From stress-set curves are derived proof stresses based on five different percentages of permanent set. The influence of prior plastic extension on these values is illustrated and discussed. A discussion is given of the influence of work-hardening, rest interval, and internal stress on the form of the proof stress-extension curve.
Date: February 23, 1940
Creator: McAdam, D. J., Jr. & Mebs, R. W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Application of the Methods of Gas Dynamics to Water Flows With Free Surface 1: Flows With No Energy Dissipation

Description: The application is treated in sufficient detail to facilitate as much as possible its application by the engineer who is less familiar with the subject. The present work was undertaken with two objects in view. In the first place, it is considered as a contribution to the water analogy of gas flows, and secondly, a large portion is devoted to the general theory of the two-dimensional supersonic flows.
Date: March 1940
Creator: Preiswerk, Ernst
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Application of the Methods of Gas Dynamics to Water Flows With Free Surface 2: Flows With Momentum Discontinuities (Hydraulic Jumps)

Description: In this paper an introduction to shock polar diagrams is given which then leads into an examination of water depths in hydraulic jumps. Energy loss during these jumps is considered along with an extended look at elementary solutions of flow. An experimental test set-up is described and the results presented.
Date: March 1940
Creator: Preiswerk, Ernst
Item Type: Refine your search to only Report
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
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Estimation of Critical Speeds of Airfoils and Streamline Bodies

Description: Report presenting methods and charts for estimating the critical compressibility speeds of a large number of airfoils and streamline bodies. The systematic effects of thickness, thickness distribution, camber, camber location, leading-edge radius, and lift coefficient are considered. The results indicate that with a given lift coefficient, the thickness of the airfoil or of the body is the primary factor controlling its critical speed.
Date: March 1940
Creator: Robinson, Russell G. & Wright, Ray H.
Item Type: Refine your search to only Report
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.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Measurement of Knock Characteristics in Spark-Ignition Engines

Description: This paper presents a discussion of three potential sources of error in recording engine knocking which are: the natural oscillation of the membrane, the shock process between test contacts, and the danger of burned contacts. Following this discussion, the paper calls attention to various results which make the bouncing-pin indicator appear fundamentally unsuitable for recording knock phenomena.
Date: March 1940
Creator: Schütz, R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Shock-Absorbed System of the Airplane Landing Gear

Description: "A discussion is given of the behavior of the shock-absorbing system, consisting of elastic struts and tires, under landing, take-off, and taxying conditions, and a general formula derived for obtaining the minimum stroke required to satisfy the conditions imposed on the landing gear. Finally, the operation of some typical shock-absorbing systems are examined and the necessity brought out for taking into account, in dynamic landing-gear tests, the effect of the wing lift at the instant of conta… more
Date: March 1940
Creator: Callerio, Pietro
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Stresses in Single-Spar Wing Constructions With Incompletely Built-Up Ribs

Description: It is shown that the force distribution resulting from incomplete ribs in single spar wing structures may be determined with the aid of the shear field method by a statistically indeterminate computation. A numerical computation is given of the force distribution of a wing structure whose two neighboring incomplete ribs with web missing in half the section are torsionally loaded.
Date: March 1940
Creator: Reinitzhuber, F.
Item Type: Refine your search to only Report
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.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A theoretical study of lateral stability with an automatic pilot

Description: "The influence of automatic operation of the aileron and rudder controls on the lateral stability of an airplane is discussed. The control deflections are assumed to be proportional to the deviations and to the rates of deviation of the airplane from steady-flight conditions. The effects of changes in the types of deviation governing control application are considered. For one simple method of control in which the aileron deflection is proportional to the angle of bank and the rudder deflection… more
Date: March 4, 1940
Creator: Imlay, Frederick H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Investigations on the Incompletely Developed Plane Diagonal-Tension Field

Description: This report presents the results of an investigation on the incompletely developed diagonal-tension field. Actual diagonal-tension beams work in an intermediate stage between pure shear and pure diagonal tension; the theory developed by Wagner for diagonal tension is not directly applicable.
Date: March 28, 1940
Creator: Kuhn, Paul
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Preliminary investigation of the flying qualities of airplanes

Description: "The National Advisory Committee for Aeronautics is undertaking an investigation of the flying qualities of airplanes. The work consists in the determination of the significant qualities susceptible of measurement, the development of the instruments required to make the measurements, and the accumulation of data on the flying qualities of existing airplanes, which data are to serve as a basis for quantitative specifications for the flying qualities of future designs" (p. 449).
Date: March 29, 1940
Creator: Soulé, H. A.
Item Type: Refine your search to only Report
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.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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High-Speed Tests of a Model Twin-Engine Low-Wing Transport Airplane

Description: "Force tests were made of a 1/8-scale model of a twin-engine low-wing transport airplane in the NACA 8-foot high-speed wind tunnel to investigate compressibility and interference effects at speeds up to 450 miles per hour. In addition to tests of the standard arrangement of the model tests were made with several modifications designed to reduce the drag and to increase the critical speed. The results show serious increases in drag at critical speeds below 450 miles per hour due to the occurrenc… more
Date: April 1940
Creator: Becker, John V. & Leonard, Lloyd H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The Lead Susceptibility of Fuels and Its Dependence on the Chemical Composition

Description: The fact that by the use of tetraethyl lead a number of otherwise unsuitable fuels could be made to meet engine requirements was not sufficiently appreciated. While use of tetraethyl lead is limited, the addition of special leaded fuels that increase the octane number is a requirement for many fuels. In this connection, the extent to which the action of tetraethyl lead through the addition of knock-resistant hydrocarbons to the base gasoline is influenced, is quite important. To the elucidation… more
Date: April 1940
Creator: Widmaier, O.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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