Latest content added for UNT Digital Libraryhttps://digital.library.unt.edu/search/?t=fulltext&fq=str_month%3A02_feb&sort=creator&display=grid2021-03-22T11:17:55-05:00UNT LibrariesThis is a custom feed for searching UNT Digital LibraryModel Supports and Their Effects on the Results of Wind Tunnel Tests2011-11-11T19:22:00-06:00https://digital.library.unt.edu/ark:/67531/metadc53815/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc53815/"><img alt="Model Supports and Their Effects on the Results of Wind Tunnel Tests" title="Model Supports and Their Effects on the Results of Wind Tunnel Tests" src="https://digital.library.unt.edu/ark:/67531/metadc53815/small/"/></a></p><p>"The airflow about a model while being tested is often sufficiently affected by the model support to lead to erroneous conclusions unless appropriate corrections are used. In this paper some new material on the subject is presented, together with a review of the airfoil support corrections used in several other laboratories" (p. 1).</p>The Theory of the Screw Propeller2011-11-11T19:22:00-06:00https://digital.library.unt.edu/ark:/67531/metadc53745/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc53745/"><img alt="The Theory of the Screw Propeller" title="The Theory of the Screw Propeller" src="https://digital.library.unt.edu/ark:/67531/metadc53745/small/"/></a></p><p>Given here is a brief review of the fundamental principles of the propeller slip-stream theory and its further development through later researches, which demonstrate the connection between the propeller slip-stream theory and Frounde's so-called 'propeller blade theory.' The propeller slip-stream theory, especially in its improved form, now gives us the basis for determining the mutual influence of the parts of the blade, so that, in calculating the shape of the blade, we can get along with certain section characteristics, which have been determined once and for all. It is argued that new theories present the possibility of investigating the phenomena in the vicinity of the propeller, allowing us to calculate its action on the basis of fewer experimental values.</p>Effect of Speed on Economy of Airship Traffic2011-11-17T22:13:23-06:00https://digital.library.unt.edu/ark:/67531/metadc59065/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc59065/"><img alt="Effect of Speed on Economy of Airship Traffic" title="Effect of Speed on Economy of Airship Traffic" src="https://digital.library.unt.edu/ark:/67531/metadc59065/small/"/></a></p><p>The economic costs and benefits of speed on airship traffic are calculated and different factors are considered.</p>Effect of Intake Pipe on the Volumetric Efficiency of an Internal Combustion Engine2011-11-17T22:13:23-06:00https://digital.library.unt.edu/ark:/67531/metadc65350/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc65350/"><img alt="Effect of Intake Pipe on the Volumetric Efficiency of an Internal Combustion Engine" title="Effect of Intake Pipe on the Volumetric Efficiency of an Internal Combustion Engine" src="https://digital.library.unt.edu/ark:/67531/metadc65350/small/"/></a></p><p>" The writer discusses the phenomena of expansion and compression which alternately take place in the cylinders of four-stroke engines during the induction process at a high mean piston speed due to the inertia and elasticity of the mixture in the intake pipe. The present paper is intended to demonstrate theoretically the existence of a most favorable pipe length for charging" (p. 1).</p>The Resistance to the Steady Motion of Small Spheres in Fluids2011-11-11T19:22:00-06:00https://digital.library.unt.edu/ark:/67531/metadc53893/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc53893/"><img alt="The Resistance to the Steady Motion of Small Spheres in Fluids" title="The Resistance to the Steady Motion of Small Spheres in Fluids" src="https://digital.library.unt.edu/ark:/67531/metadc53893/small/"/></a></p><p>"There seems to be little reliable information conveniently available as to the resistance encountered by small spheres moving steadily at moderate speeds in fluids. The present paper, while presenting nothing new in the way of either theory or data, has three objects: first to show that published data are sufficient to furnish approximate information; second to present this information in form convenient for computation; and, third to indicate where further research is needed" (p. 1).</p>The Metal Construction of Airplanes - Its Advantages - Its Present State - Its Future2014-03-22T10:27:53-05:00https://digital.library.unt.edu/ark:/67531/metadc277552/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc277552/"><img alt="The Metal Construction of Airplanes - Its Advantages - Its Present State - Its Future" title="The Metal Construction of Airplanes - Its Advantages - Its Present State - Its Future" src="https://digital.library.unt.edu/ark:/67531/metadc277552/small/"/></a></p><p>The use of duralumin by French airplane designers is presented, the results they have obtained, and their hopes for the future.</p>Causes of cracking of ignition cable2011-11-11T19:22:00-06:00https://digital.library.unt.edu/ark:/67531/metadc53716/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc53716/"><img alt="Causes of cracking of ignition cable" title="Causes of cracking of ignition cable" src="https://digital.library.unt.edu/ark:/67531/metadc53716/small/"/></a></p><p>From Summary: "The experiments described here show that the cracking at sharp bends, observed in the insulation of internal combustion engine high tension ignition wires after service, is due to a chemical attack upon the rubber by the ozone produced by the electric discharge that takes place at the surface of the cable. This cracking does not occur if the insulating material is not under tension, or if the cable is surrounded by some medium other than air. But it does occur even if the insulation is not subjected to electric stress, provided that the atmosphere near the cable contains ozone. The extent of this cracking varies greatly with the insulating material used. The cracking can be materially reduced by using braided cable and by avoiding sharp bends."</p>Surface area coefficients for airship envelopes2011-11-11T19:22:00-06:00https://digital.library.unt.edu/ark:/67531/metadc53750/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc53750/"><img alt="Surface area coefficients for airship envelopes" title="Surface area coefficients for airship envelopes" src="https://digital.library.unt.edu/ark:/67531/metadc53750/small/"/></a></p><p>"In naval architecture, it is customary to determine the wetted surface of a ship by means of some formula which involves the principal dimensions of the design and suitable constants. These formulas of naval architecture may be extended and applied to the calculation of the surface area of airship envelopes by the use of new values of the constants determined for this purpose. Surface area coefficients were calculated from the actual dimensions, surfaces, and volumes of 52 streamline bodies, which form a series covering the entire range of shapes used in the present aeronautical practice" (p. 1).</p>The Air Propeller, Its Strength and Correct Shape2011-11-11T19:22:00-06:00https://digital.library.unt.edu/ark:/67531/metadc53811/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc53811/"><img alt="The Air Propeller, Its Strength and Correct Shape" title="The Air Propeller, Its Strength and Correct Shape" src="https://digital.library.unt.edu/ark:/67531/metadc53811/small/"/></a></p><p>It is possible to give a propeller such a shape that, under given conditions, viz., a definite speed of revolution and flying speed, the bending stresses in the blades will assume quite an insignificant magnitude.</p>Aviation Fuels (With Especial Reference To "White Spirit")2011-11-17T22:13:23-06:00https://digital.library.unt.edu/ark:/67531/metadc65274/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc65274/"><img alt="Aviation Fuels (With Especial Reference To "White Spirit")" title="Aviation Fuels (With Especial Reference To "White Spirit")" src="https://digital.library.unt.edu/ark:/67531/metadc65274/small/"/></a></p><p>Gasoline, the fuel now used, is an extremely volatile and inflammable liquid capable of forming explosive mixtures, the cause of many catastrophes in aviation. It is therefore of special interest to investigate the possibility of using fuels which, while being less volatile than gasoline, would nevertheless enable this engine to function satisfactorily.</p>Longitudinal Balancing of Airplanes2014-03-22T10:27:53-05:00https://digital.library.unt.edu/ark:/67531/metadc277433/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc277433/"><img alt="Longitudinal Balancing of Airplanes" title="Longitudinal Balancing of Airplanes" src="https://digital.library.unt.edu/ark:/67531/metadc277433/small/"/></a></p><p>The object of the present communication is to determine the best method for locating the center of lift of an airplane and to provide a method for making corrections. The method employed is very simple, being based on the positions given the elevator during flights at different speeds.</p>Aeronautic Instruments2014-03-22T10:27:53-05:00https://digital.library.unt.edu/ark:/67531/metadc277462/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc277462/"><img alt="Aeronautic Instruments" title="Aeronautic Instruments" src="https://digital.library.unt.edu/ark:/67531/metadc277462/small/"/></a></p><p>"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" (p. 1).</p>Fixed Air-Cooled Engines2014-03-22T10:27:53-05:00https://digital.library.unt.edu/ark:/67531/metadc277503/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc277503/"><img alt="Fixed Air-Cooled Engines" title="Fixed Air-Cooled Engines" src="https://digital.library.unt.edu/ark:/67531/metadc277503/small/"/></a></p><p>"It is proposed to analyze the advantages and disadvantages of large fixed air-cooled radial engines and to explain how the problems have been solved by the Bristol Aeroplane Company" (p. 1).</p>The comparative performance of an aviation engine at normal and high inlet air temperatures2011-11-17T22:13:23-06:00https://digital.library.unt.edu/ark:/67531/metadc65930/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc65930/"><img alt="The comparative performance of an aviation engine at normal and high inlet air temperatures" title="The comparative performance of an aviation engine at normal and high inlet air temperatures" src="https://digital.library.unt.edu/ark:/67531/metadc65930/small/"/></a></p><p>"This report presents some results obtained during an investigation to determine the effect of high inlet air temperature on the performance of a Liberty 12 aviation engine. The purpose of this investigation was to ascertain, for normal service carburetor adjustments and a fixed ignition advance, the relation between power and temperature for the range of carburetor air temperatures that may be encountered when supercharging to sea level pressure at altitudes of over 20,000 feet and without intercooling when using plain aviation gasoline and mixtures of benzol and gasoline" (p. 409).</p>The relative performance obtained with several methods of control of an overcompressed engine using gasoline2011-11-17T22:13:23-06:00https://digital.library.unt.edu/ark:/67531/metadc65925/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc65925/"><img alt="The relative performance obtained with several methods of control of an overcompressed engine using gasoline" title="The relative performance obtained with several methods of control of an overcompressed engine using gasoline" src="https://digital.library.unt.edu/ark:/67531/metadc65925/small/"/></a></p><p>"This report presents some results obtained during an investigation to determine the relative characteristics for several methods of control of an overcompressed engine using gasoline and operating under sea-level conditions. For this work, a special single cylinder test engine, 5-inch bore by 7-inch stroke, and designed for ready adjustment of compression ratio, valve timing and valve lift while running, was used. This engine has been fully described in NACA-TR-250. Tests were made at an engine speed of 1,400 R. P. M. for compression ratios ranging from 4.0 to 7.6" (p. 329).</p>Testing of Fire-Clay Brick with Special Reference to their Use in Coal-Fired Boiler Settings2012-10-17T09:47:01-05:00https://digital.library.unt.edu/ark:/67531/metadc66511/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc66511/"><img alt="Testing of Fire-Clay Brick with Special Reference to their Use in Coal-Fired Boiler Settings" title="Testing of Fire-Clay Brick with Special Reference to their Use in Coal-Fired Boiler Settings" src="https://digital.library.unt.edu/ark:/67531/metadc66511/small/"/></a></p><p>Technical paper issued by the Bureau of Standards over studies conducted on fire-clay bricks. The results of the studies are discussed. This paper includes tables, and illustrations.</p>Practical Method for Balancing Airplane Moments2011-11-11T19:22:00-06:00https://digital.library.unt.edu/ark:/67531/metadc53849/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc53849/"><img alt="Practical Method for Balancing Airplane Moments" title="Practical Method for Balancing Airplane Moments" src="https://digital.library.unt.edu/ark:/67531/metadc53849/small/"/></a></p><p>"The present contribution is the sequel to a paper written by Messrs. R. Fuchs, L. Hopf, and H. Hamburger, and proposes to show that the methods therein contained can be practically utilized in computations. Furthermore, the calculations leading up to the diagram of moments for three airplanes, whose performance in war service gave reason for complaint, are analyzed. Finally, it is shown what conclusions can be drawn from the diagram of moments with regard to the defects in these planes and what steps may be taken to remedy them" (p. 1).</p>High-Speed Oil Engines for Vehicles Part 1: Engines With External Atomization of the Fuel, Engines With Internal Atomization of the Fuel, Hot-Bulb Engines, Diesel Engines2011-11-17T22:13:23-06:00https://digital.library.unt.edu/ark:/67531/metadc65209/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc65209/"><img alt="High-Speed Oil Engines for Vehicles Part 1: Engines With External Atomization of the Fuel, Engines With Internal Atomization of the Fuel, Hot-Bulb Engines, Diesel Engines" title="High-Speed Oil Engines for Vehicles Part 1: Engines With External Atomization of the Fuel, Engines With Internal Atomization of the Fuel, Hot-Bulb Engines, Diesel Engines" src="https://digital.library.unt.edu/ark:/67531/metadc65209/small/"/></a></p><p>Different engines are tested to determine their efficiencies in burning fuel. Fuel injection and ignition chamber engines are also discussed.</p>The Measurement of Pressure Through Tubes in Pressure Distribution Tests2011-11-17T22:13:23-06:00https://digital.library.unt.edu/ark:/67531/metadc65923/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc65923/"><img alt="The Measurement of Pressure Through Tubes in Pressure Distribution Tests" title="The Measurement of Pressure Through Tubes in Pressure Distribution Tests" src="https://digital.library.unt.edu/ark:/67531/metadc65923/small/"/></a></p><p>"The tests described in this report were made to determine the error caused by using small tubes to connect orifices on the surface of aircraft to central pressure capsules in making pressure distribution tests. Aluminum tubes of 3/16-inch inside diameter were used to determine this error. Lengths from 20 feet to 226 feet and pressures whose maxima varied from 2 inches to 140 inches of water were used. Single-pressure impulses for which the time of rise of pressure from zero to a maximum varied from 0.25 second to 3 seconds were investigated" (p. 303).</p>Marking Airdromes2011-11-11T19:22:00-06:00https://digital.library.unt.edu/ark:/67531/metadc53661/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc53661/"><img alt="Marking Airdromes" title="Marking Airdromes" src="https://digital.library.unt.edu/ark:/67531/metadc53661/small/"/></a></p><p>Necessity of adopting for all aviation fields, civil or military, a single system of markers for giving the direction for starting and landing (with an automatic indicator of the direction of the wind) and of indicating the good part of the field.</p>The Aerodynamical Laboratory of the Vienna Technical High School2011-11-11T19:22:00-06:00https://digital.library.unt.edu/ark:/67531/metadc53660/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc53660/"><img alt="The Aerodynamical Laboratory of the Vienna Technical High School" title="The Aerodynamical Laboratory of the Vienna Technical High School" src="https://digital.library.unt.edu/ark:/67531/metadc53660/small/"/></a></p><p>Report presenting a description of the aerodynamics laboratory of the Vienna Technical High School. The main focus of this report is detailing some of the accomplishments that the laboratory has made.</p>Danger of Ice Formation on Airplanes2011-11-17T22:13:23-06:00https://digital.library.unt.edu/ark:/67531/metadc65349/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc65349/"><img alt="Danger of Ice Formation on Airplanes" title="Danger of Ice Formation on Airplanes" src="https://digital.library.unt.edu/ark:/67531/metadc65349/small/"/></a></p><p>This paper relates the different types of ice formations that can occur on airplanes and the dangers that they pose.</p>Pitot-Static Tubes for Determining the Velocity of Air2011-11-17T22:13:23-06:00https://digital.library.unt.edu/ark:/67531/metadc59066/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc59066/"><img alt="Pitot-Static Tubes for Determining the Velocity of Air" title="Pitot-Static Tubes for Determining the Velocity of Air" src="https://digital.library.unt.edu/ark:/67531/metadc59066/small/"/></a></p><p>On the occasion of the formulation of the rules for testing the efficiency of ventilators and compressors, experiments were instituted by the subcommittee on ventilators for the production of suitable tubes for velocity and pressure measurements.</p>On the Mutual Reaction of Wings and Body2011-11-17T22:13:23-06:00https://digital.library.unt.edu/ark:/67531/metadc65212/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc65212/"><img alt="On the Mutual Reaction of Wings and Body" title="On the Mutual Reaction of Wings and Body" src="https://digital.library.unt.edu/ark:/67531/metadc65212/small/"/></a></p><p>"At the suggestion of Professor Von Karman, I have made a few theoretical investigations of the mutual reaction of the wings and body of an airplane. There was assumed as the basis of my calculations, a strongly idealized body shape, namely, a cylinder extended to infinity at both ends and having its axis parallel to the direction of motion of the airplane. The results are to be regarded as rough approximations for a long airplane body and also for an airship with fins. In my calculations, I have considered only a monoplane in which the axis of the wing is rectilinear" (p. 1).</p>Technical Section of Aeronautics2014-03-22T10:27:53-05:00https://digital.library.unt.edu/ark:/67531/metadc277418/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc277418/"><img alt="Technical Section of Aeronautics" title="Technical Section of Aeronautics" src="https://digital.library.unt.edu/ark:/67531/metadc277418/small/"/></a></p><p>The duties of the Technical Section are listed along with facilities for testing. Different categories of tests are discussed and some sample results included.</p>Magnan Glider M-22014-03-22T10:27:53-05:00https://digital.library.unt.edu/ark:/67531/metadc277571/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc277571/"><img alt="Magnan Glider M-2" title="Magnan Glider M-2" src="https://digital.library.unt.edu/ark:/67531/metadc277571/small/"/></a></p><p>The construction of the Magnan glider, M-2, is presented which is designed to fly in so-called horizontal winds. Details of the wings, fuselage, tail surfaces, controls, landing gear, characteristics, operation, photographs, and drawings are provided.</p>A New Method for the Prediction of Airplane Performance2011-11-14T19:18:49-06:00https://digital.library.unt.edu/ark:/67531/metadc53980/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc53980/"><img alt="A New Method for the Prediction of Airplane Performance" title="A New Method for the Prediction of Airplane Performance" src="https://digital.library.unt.edu/ark:/67531/metadc53980/small/"/></a></p><p>A new method for the prediction of airplane performance in level and climbing flight, together with complete information regarding propeller speeds, is described in this report. Developed from Bairstow's system and making use of American absolute coefficients, this method has advantages of simplicity and brevity.</p>Discharge Characteristics of a High Speed Fuel Injection System2011-11-11T19:22:00-06:00https://digital.library.unt.edu/ark:/67531/metadc53894/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc53894/"><img alt="Discharge Characteristics of a High Speed Fuel Injection System" title="Discharge Characteristics of a High Speed Fuel Injection System" src="https://digital.library.unt.edu/ark:/67531/metadc53894/small/"/></a></p><p>Discussed here are some discharge characteristics of a fuel injection system intended primarily for high speed service. The system consisted of a cam actuated fuel pump, a spring loaded automatic injection valve, and a connecting tube.</p>Increasing the Compression Pressure in an Engine by Using a Long Intake Pipe2011-11-11T19:22:00-06:00https://digital.library.unt.edu/ark:/67531/metadc53851/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc53851/"><img alt="Increasing the Compression Pressure in an Engine by Using a Long Intake Pipe" title="Increasing the Compression Pressure in an Engine by Using a Long Intake Pipe" src="https://digital.library.unt.edu/ark:/67531/metadc53851/small/"/></a></p><p>"During some tests of a one-cylinder engine, using gas oil (diesel engine oil, specific gravity 0.86 at 60 F) with solid injection and compression ignition, it was found to be necessary to increase either the jacket water temperature or the compression pressure in order to start the engine. It was found that a sufficient increase in compression pressure could be obtained simply by attaching a long pipe to the inlet flange of the cylinder. However, since no data were available giving the values of the increase in compression pressure that might be expected from such a step-up, an investigation was made covering some engine speeds between 500 r.p.m. and 1800 r.p.m." (p. 1).</p>The Efficiency of a Wind Tunnel2011-11-11T19:22:00-06:00https://digital.library.unt.edu/ark:/67531/metadc53664/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc53664/"><img alt="The Efficiency of a Wind Tunnel" title="The Efficiency of a Wind Tunnel" src="https://digital.library.unt.edu/ark:/67531/metadc53664/small/"/></a></p><p>If, by some means, a steady state of motion of a perfect fluid were established in an ideal wind tunnel, there would be no losses, and the motion would persist indefinitely. In the actual tunnel, the function of the motor-fan group is overcome by the total loss of head in the tube due to friction and eddies.</p>Tests on an Airplane Model, AEG D I of the Allgemeine Elektricitats Gesellschft, A-G, Airplane Construction Section Conducted at the Gottingen Model Testing Laboratory for Aerodynamics2011-11-11T19:22:00-06:00https://digital.library.unt.edu/ark:/67531/metadc53812/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc53812/"><img alt="Tests on an Airplane Model, AEG D I of the Allgemeine Elektricitats Gesellschft, A-G, Airplane Construction Section Conducted at the Gottingen Model Testing Laboratory for Aerodynamics" title="Tests on an Airplane Model, AEG D I of the Allgemeine Elektricitats Gesellschft, A-G, Airplane Construction Section Conducted at the Gottingen Model Testing Laboratory for Aerodynamics" src="https://digital.library.unt.edu/ark:/67531/metadc53812/small/"/></a></p><p>"Tests were carried out in the small wind tunnel of the Gottingen establishment on a complete model of the AEG D I airplane. The agreement between the model and the complete airplane applies particularly to the wings, which have ribs cut out of sheet metal and built up in exactly the same manner as in the actual airplane. Various series of tests were carried out with this model in which one or the other of the control surfaces were adjusted to various angles, while the others remained in their neutral positions" (p. 1).</p>Parachutes for Aircraft2014-03-22T10:27:53-05:00https://digital.library.unt.edu/ark:/67531/metadc277409/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc277409/"><img alt="Parachutes for Aircraft" title="Parachutes for Aircraft" src="https://digital.library.unt.edu/ark:/67531/metadc277409/small/"/></a></p><p>Report covering some characteristics of parachutes for aircraft. In order to provide the essential data on air resistance, rapidity of opening, shock stresses in opening, etc., for subsequent use, we will first give a few test results.</p>Duralumin Welding2011-11-17T22:13:23-06:00https://digital.library.unt.edu/ark:/67531/metadc65211/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc65211/"><img alt="Duralumin Welding" title="Duralumin Welding" src="https://digital.library.unt.edu/ark:/67531/metadc65211/small/"/></a></p><p>Gas and electric welding of duralumin are discussed. Some of the elements that go into determining a successful weld and inspecting for faults are also described.</p>Tests of Lignite Char as Reduction Fuel in the Smelting of Zinc Ores2021-03-22T11:17:55-05:00https://digital.library.unt.edu/ark:/67531/metadc1393304/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc1393304/"><img alt="Tests of Lignite Char as Reduction Fuel in the Smelting of Zinc Ores" title="Tests of Lignite Char as Reduction Fuel in the Smelting of Zinc Ores" src="https://digital.library.unt.edu/ark:/67531/metadc1393304/small/"/></a></p><p>This report analyzes experiments made to develop a method of utilizing the immense deposits of lignite in the United States.</p>Note on the Katzmayr Effect on Airfoil Drag2011-11-11T19:22:00-06:00https://digital.library.unt.edu/ark:/67531/metadc53897/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc53897/"><img alt="Note on the Katzmayr Effect on Airfoil Drag" title="Note on the Katzmayr Effect on Airfoil Drag" src="https://digital.library.unt.edu/ark:/67531/metadc53897/small/"/></a></p><p>The reduction of drag of an airfoil when the air stream is oscillating is called the Katzmayr effect. The purpose here is to offer a simple explanation of the cause of the Katzmayr effect.</p>Preparation and Uses of Tar and its Simple Crude Derivatives2012-10-17T09:47:01-05:00https://digital.library.unt.edu/ark:/67531/metadc66437/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc66437/"><img alt="Preparation and Uses of Tar and its Simple Crude Derivatives" title="Preparation and Uses of Tar and its Simple Crude Derivatives" src="https://digital.library.unt.edu/ark:/67531/metadc66437/small/"/></a></p><p>Technical paper issued by the Bureau of Mines over studies of coal tars. As stated in the introduction, "this paper discusses the uses to which some of the various tars are put and shows briefly the usual methods of working up tar into some of its simple or easily prepared derivatives, for which a market can generally be found" (p. 5). This paper includes tables, illustrations, and photographs.</p>Aerial Transportation2011-11-11T19:22:00-06:00https://digital.library.unt.edu/ark:/67531/metadc53663/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc53663/"><img alt="Aerial Transportation" title="Aerial Transportation" src="https://digital.library.unt.edu/ark:/67531/metadc53663/small/"/></a></p><p>Report discussing the origin of air traffic dates from the war. The important development of aeronautic industries and the progress made in recent years, under the impelling force of circumstances, rendered it possible, after the close of hostilities, to consider the practical utilization of this new means of economic expansion.</p>Induced Drag of Multiplanes2011-11-11T19:22:00-06:00https://digital.library.unt.edu/ark:/67531/metadc53856/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc53856/"><img alt="Induced Drag of Multiplanes" title="Induced Drag of Multiplanes" src="https://digital.library.unt.edu/ark:/67531/metadc53856/small/"/></a></p><p>"The most important part of the resistance or drag of a wing system, the induced drag, can be calculated theoretically, when the distribution of lift on the individual wings is known. The calculation is based upon the assumption that the lift on the wings is distributed along the wing in proportion to the ordinates of a semi-ellipse. Formulas and numerical tables are given for calculating the drag. In this connection, the most favorable arrangements of biplanes and triplanes are discussed and the results are further elucidated by means of numerical examples" (p. 1).</p>Lessons of the 1922 Rhön Soaring Flights2011-11-16T07:33:14-06:00https://digital.library.unt.edu/ark:/67531/metadc56200/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc56200/"><img alt="Lessons of the 1922 Rhön Soaring Flights" title="Lessons of the 1922 Rhön Soaring Flights" src="https://digital.library.unt.edu/ark:/67531/metadc56200/small/"/></a></p><p>Innovations in design and technique from the Rhön soaring contest are presented in this report.</p>A New Interferential Dilatometer2012-10-17T09:47:01-05:00https://digital.library.unt.edu/ark:/67531/metadc66487/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc66487/"><img alt="A New Interferential Dilatometer" title="A New Interferential Dilatometer" src="https://digital.library.unt.edu/ark:/67531/metadc66487/small/"/></a></p><p>Scientific paper issued by the Bureau of Mines over development of a dilatometer. The instrument is used in tests of thermal expansion. The methods are presented and discussed. This paper includes an illustration.</p>Results of Aerodynamic Tests on Slotted Airfoils in the Aerotechnical Laboratory (S.T. Ae.) of Rhode St. Genese, Brussels2011-11-17T22:13:23-06:00https://digital.library.unt.edu/ark:/67531/metadc65272/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc65272/"><img alt="Results of Aerodynamic Tests on Slotted Airfoils in the Aerotechnical Laboratory (S.T. Ae.) of Rhode St. Genese, Brussels" title="Results of Aerodynamic Tests on Slotted Airfoils in the Aerotechnical Laboratory (S.T. Ae.) of Rhode St. Genese, Brussels" src="https://digital.library.unt.edu/ark:/67531/metadc65272/small/"/></a></p><p>Report investigating the maximum lift obtainable with slotted airfoils derived from a symmetrical airfoil. These should have a smaller profile drag than other slotted airfoils.</p>Corrosion Embrittlement of Duralumin. V: Results of Weather-Exposure Tests2011-11-14T19:18:49-06:00https://digital.library.unt.edu/ark:/67531/metadc53984/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc53984/"><img alt="Corrosion Embrittlement of Duralumin. V: Results of Weather-Exposure Tests" title="Corrosion Embrittlement of Duralumin. V: Results of Weather-Exposure Tests" src="https://digital.library.unt.edu/ark:/67531/metadc53984/small/"/></a></p><p>In a series of weather exposure tests of sheet duralumin, upon which accelerated corrosion tests in the laboratory by the wet-and-dry corrosion method in a sodium chloride solution has already been carried out, a close parallelism between the results of the two kinds of tests was found to exist. The exposure tests showed that the lack of permanence of sheet duralumin is largely, if not entirely, due to corrosion. A corrosion attack of an intercrystalline nature is very largely responsible for the degree of embrittlement produced.</p>Welding in Airplane Construction2011-11-17T22:13:23-06:00https://digital.library.unt.edu/ark:/67531/metadc65290/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc65290/"><img alt="Welding in Airplane Construction" title="Welding in Airplane Construction" src="https://digital.library.unt.edu/ark:/67531/metadc65290/small/"/></a></p><p>The present article attempts to explain the principles for the production of a perfect weld and to throw light on the unexplained problems. Moreover, it is intended to elucidate the possibilities of testing the strength and reliability of welded parts.</p>The laboratories of the Technical Section of Aeronautics (Service Technique de L'Aeronautique or S.T.Ae.)2014-03-22T10:27:53-05:00https://digital.library.unt.edu/ark:/67531/metadc277478/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc277478/"><img alt="The laboratories of the Technical Section of Aeronautics (Service Technique de L'Aeronautique or S.T.Ae.)" title="The laboratories of the Technical Section of Aeronautics (Service Technique de L'Aeronautique or S.T.Ae.)" src="https://digital.library.unt.edu/ark:/67531/metadc277478/small/"/></a></p><p>An historical sketch of the laboratories of the Technical Section is provided. A breakdown of the different departments and their specialties is also listed.</p>Methods of experimentation with models and utilization of results2014-03-22T10:27:53-05:00https://digital.library.unt.edu/ark:/67531/metadc277553/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc277553/"><img alt="Methods of experimentation with models and utilization of results" title="Methods of experimentation with models and utilization of results" src="https://digital.library.unt.edu/ark:/67531/metadc277553/small/"/></a></p><p>The present report treats the subject of testing small models in a wind tunnel and of the methods employed for rendering the results constant, accurate and comparable with one another. Detailed experimental results are given.</p>Researches on ailerons and especially on the test loads to which they should be subjected2014-03-22T10:27:53-05:00https://digital.library.unt.edu/ark:/67531/metadc277422/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc277422/"><img alt="Researches on ailerons and especially on the test loads to which they should be subjected" title="Researches on ailerons and especially on the test loads to which they should be subjected" src="https://digital.library.unt.edu/ark:/67531/metadc277422/small/"/></a></p><p>Aileron calculations have hitherto given greatly differing results according to different authors. It seems to be the general opinion that it is only necessary to give the ailerons such dimensions that the airplane can maneuver well, that the stresses they must undergo are relatively small, and that they are strong enough if their framework is of the order of strength as the wings to which they are attached. This article will show that the problem is really quite complex and that it should receive more attention.</p>Kirsten-Boeing Propeller2011-11-17T22:13:23-06:00https://digital.library.unt.edu/ark:/67531/metadc65157/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc65157/"><img alt="Kirsten-Boeing Propeller" title="Kirsten-Boeing Propeller" src="https://digital.library.unt.edu/ark:/67531/metadc65157/small/"/></a></p><p>The advantages of the Kirsten-Boeing propeller consist essentially in the adjustability of the thrust in any desired direction, in the plane perpendicular to the axis of rotation of the system, and in its high efficiency. The propeller, which greatly resembles the paddle wheels used on river steamers, differs fundamentally from the latter, in that all the blades work simultaneously in the fluid medium (air or water).</p>Loads and Calculations of Army Airplanes2011-11-11T19:22:00-06:00https://digital.library.unt.edu/ark:/67531/metadc53704/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc53704/"><img alt="Loads and Calculations of Army Airplanes" title="Loads and Calculations of Army Airplanes" src="https://digital.library.unt.edu/ark:/67531/metadc53704/small/"/></a></p><p>By comparing airplanes of known strength that have resisted all the usual and even extreme air loads with those that under like conditions were found to be insufficiently strong, the researchers, aided by scientific investigations, developed standards which are satisfactory for the calculation of airplane structures. Given here are standards applicable to loads on wing trusses, load factors for use in stress analysis, load factors required in sand testing, loads on control surfaces, loads on wing ribs, loads on landing gear, and rigidity of materials.</p>Note on the Resistance of Polished Cylinders (and Cylindrical Wires) With Generatrices Perpendicular to the Airstream2011-11-11T19:22:00-06:00https://digital.library.unt.edu/ark:/67531/metadc53793/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc53793/"><img alt="Note on the Resistance of Polished Cylinders (and Cylindrical Wires) With Generatrices Perpendicular to the Airstream" title="Note on the Resistance of Polished Cylinders (and Cylindrical Wires) With Generatrices Perpendicular to the Airstream" src="https://digital.library.unt.edu/ark:/67531/metadc53793/small/"/></a></p><p>Report presenting a review of currently published documents regarding the resistance of polished cylinders with generators perpendicular to the airstream. The discrepancies between these various studies are pointed out.</p>Remarks on Airplane Struts and Girders Under Compressive and Bending Stresses: Index Values2011-11-17T22:13:23-06:00https://digital.library.unt.edu/ark:/67531/metadc65287/<p><a href="https://digital.library.unt.edu/ark:/67531/metadc65287/"><img alt="Remarks on Airplane Struts and Girders Under Compressive and Bending Stresses: Index Values" title="Remarks on Airplane Struts and Girders Under Compressive and Bending Stresses: Index Values" src="https://digital.library.unt.edu/ark:/67531/metadc65287/small/"/></a></p><p>In this paper the behavior of straight, centrally loaded compression struts is discussed and values computed.</p>