Search Results

open access

Working Charts for the Selection of Aluminum Alloy Propellers of a Standard Form to Operate With Various Aircraft Engines and Bodies

Description: "Working charts are given for the convenient selection of aluminum alloy propellers of a standard form, to operate in connection with six different engine-fuselage combinations. The charts have been prepared from full-scale test data obtained in the 20-foot propeller research tunnel of the National Advisory Committee for Aeronautics. An example is also given showing the use of the charts" (p. 3).
Date: March 25, 1929
Creator: Weick, Fred E.
Partner: UNT Libraries Government Documents Department
open access

The Effect of Reduction Gearing on Propeller-Body Interference as Shown by Full-Scale Wind-Tunnel Tests

Description: This report presents the results of full-scale tests made on a 10-foot 5-inch propeller on a geared J-5 engine and also on a similar 8-foot 11-inch propeller on a direct-drive J-5 engine. Each propeller was tested at two different pitch settings, and with a large and a small fuselage. The investigation was made in such a manner that the propeller-body interference factors were isolated, and it was found that, considering this interference only, the geared propellers had an appreciable advantage in propulsive efficiency, partially due to the larger diameter of the propellers with respect to the bodies, and partially because the geared propellers were located farther ahead of the engines and bodies.
Date: March 20, 1929
Creator: Weick, Fred E.
Partner: UNT Libraries Government Documents Department
open access

Full-Scale Wind-Tunnel Tests on Several Metal Propellers Having Different Blade Forms

Description: "This report gives the full-scale aerodynamic characteristics of five different aluminum alloy propellers having four different blade forms. They were tested on an open cockpit fuselage with a radial air-cooled engine having conventional cowling. The results show that (1) the differences in propulsive efficiency due to the differences in blade form were small; (2) the form with the thinnest airfoil sections had the highest efficiency; (3) it is advantageous as regards propulsive efficiency for a propeller operating in front of a body, such as a radial engine, to have its pitch reduced toward the hub" (p. 123).
Date: March 18, 1929
Creator: Weick, Fred E.
Partner: UNT Libraries Government Documents Department
open access

The Effect of Supercharger Capacity on Engine and Airplane Performance

Description: This report presents the results of an investigation to determine the effect of different supercharger capacities on the performance of an airplane and its engine . The tests were conducted on a DH4-M2 airplane powered with a Liberty 12 engine. In this investigation four supercharger capacities, obtained by driving a roots type supercharger at 1.615, 1.957, 2.4, and 3 time engine speed, were used to maintain sea-level pressure at the carburetor to altitudes of 7,000, 11,500, 17,000, and 22,000 feet, respectively. The performance of the airplane in climb and in level flight was determined for each of the four supercharger drive ratios and for the unsupercharged condition.
Date: March 13, 1929
Creator: Schey, O. W. & Gove, W. D.
Partner: UNT Libraries Government Documents Department
open access

Full-Scale Wind-Tunnel Tests With a Series of Propellers of Different Diameters on a Single Fuselage

Description: "Aerodynamic tests were made with four geometrically similar metal propellers of different diameters, on a Wright "Whirlwind" J-5 engine in an open cockpit fuselage. The results show little difference in the characteristics of the various propellers, the only one of any importance being an increase of efficiency of the order of 1 per cent for a 5 per cent increase of diameter, within the range of the tests" (p. 107).
Date: March 12, 1929
Creator: Weick, Fred E.
Partner: UNT Libraries Government Documents Department
open access

Analysis of flight and wind-tunnel tests on Udet airplanes with reference to spinning characteristics

Description: This report presents an analysis of results of wind-tunnel tests conducted at the D.V.L. Values were determined for the effectiveness of all the controls at various angles of attack. The autorotation was studied by subjecting the rotating model to an air blast.
Date: March 1929
Creator: Herrmann, H.
Partner: UNT Libraries Government Documents Department
open access

Effect of Stressed Covering on Strength of Internal Girders of a Wing

Description: In practice the actual maximum stress is greater than the stress determined by the simple girder theory, which overestimates the bearing or supporting capacity of the flange. The fact is that the assumptions of the simple girder theory no longer hold true, since normal transverse and shearing stresses are engendered in the plane of the flange.
Date: March 1929
Creator: Tellers, H.
Partner: UNT Libraries Government Documents Department
open access

Impact Waves and Detonation: Part 1

Description: "Among the numerous thermodynamic and kinetic problems that have arisen in the application of the gaseous explosive reaction as a source of power in the internal combustion engine, the problem of the mode or way by which the transformation proceeds and the rate at which the heat energy is delivered to the working fluid became very early in the engine's development a problem of prime importance. The work of Becker here given is a notable extension of earlier investigations, because it covers the entire range of the explosive reaction in gases - normal detonation and burning" (p. i).
Date: March 1929
Creator: Becker, R.
Partner: UNT Libraries Government Documents Department
open access

Impact Waves and Detonation: Part 2

Description: A continuation of a previous technical memorandum regarding impact waves and detonation. This particular report focuses on the applications to detonation under several different conditions, including variations in pressure.
Date: March 1929
Creator: Becker, R.
Partner: UNT Libraries Government Documents Department
open access

Mechanical Control of Airplanes

Description: "Before undertaking a detailed description of an automatic-control mechanism, I will state briefly the fundamental conditions for such devices. These are: 1) it must be sensitive at one or more reference values; 2) it must stop the angular motions of the airplane not produced by the pilot; and 3) it must be possible to switch it off and on by a simple hand lever" (p. 1).
Date: March 1929
Creator: Boykow, H.
Partner: UNT Libraries Government Documents Department
open access

The Measurement of Maximum Cylinder Pressures

Description: "The work presented in this report was undertaken at the Langley Memorial Aeronautical Laboratory of the National Advisory Committee for Aeronautics to determine a suitable method for measuring the maximum pressures occurring in aircraft engine cylinders. The study and development of instruments for the measurement of maximum cylinder pressures has been conducted in connection with carburetor and oil engine investigations on a single cylinder aircraft-type engine. Five maximum cylinder-pressure devices have been designed, and tested, in addition to the testing of three commercial indicators" (p. 311).
Date: March 30, 1928
Creator: Hicks, Chester W.
Partner: UNT Libraries Government Documents Department
open access

The prediction of airfoil characteristics

Description: This report describes and develops methods by which the aerodynamic characteristics of an airfoil may be calculated with sufficient accuracy for use in airplane design. These methods for prediction are based on the present aerodynamic theory and on empirical formulas derived from data obtained in the N. A. C. A. variable density wind tunnel at a Reynolds number corresponding approximately to full scale. (author).
Date: March 14, 1928
Creator: Higgins, George J.
Partner: UNT Libraries Government Documents Department
open access

The 1926 German Seaplane Contest

Description: The report discusses the problem of rating the various seaplane designs from the 1926 seaplane contest. The whole process of rating consists in measuring the climbing speed, flying weight and carrying capacity of a seaplane and then using these data as the basis of a construction problem.
Date: March 1928
Creator: Seewald, F.; Blenk, H. & Liebers, F.
Partner: UNT Libraries Government Documents Department
open access

Calculation of Airplane Performances Without the Aid of Polar Diagrams

Description: For good profiles the profile-drag coefficient is almost constant in the whole range which comes into consideration for practical flight. This is manifest in the consideration of the Gottingen airfoil tests and is confirmed by the investigations of the writer (measurements of the profile drag during flight by the Betz method), concerning which a detailed report will soon be published. The following deductions proceed from this fact. The formulas developed on the assumptions of a constant profile-drag coefficient afford an extensive insight into the influences exerted on flight performances by the structure of the airplane.
Date: March 1928
Creator: Schrenk, Martin
Partner: UNT Libraries Government Documents Department
open access

A Comparison of Propeller and Centrifugal Fans for Circulating the Air in a Wind Tunnel

Description: The tests described in this paper afford a direct comparison of the efficiency and smoothness of flow obtained with propeller fan and multiblade centrifugal fan drives in the same wind tunnel. The propeller fan was found to be superior to the centrifugal fan in that the efficiency was about twice as great, and the flow much smoother.
Date: March 1928
Creator: Weick, Fred E.
Partner: UNT Libraries Government Documents Department
open access

Drag of exposed fittings and surface irregularities on airplane fuselages

Description: Measurements of drag were made on fittings taken from a typical fuselage to determine whether the difference between the observed full size fuselage drag and model fuselage drag could be attributed to the effects of fittings and surface irregularities found on the full size fuselage and not on the model. There are wide variations in the drag coefficients for the different fittings. In general those which protrude little from the surface or are well streamlined show very low and almost negligible drag. The measurements show, however, that a large part of the difference between model and full scale test results may be attributed to these fittings.
Date: March 1928
Creator: Wood, Donald H.
Partner: UNT Libraries Government Documents Department
open access

A Few More Mechanical-Flight Formulas Without the Aid of Polar Diagrams

Description: The reliability of the assumption of a parabolic shape of the polar curve is investigated and found satisfactory for all practical purposes. It is further shown that the aerodynamically best possible or "ideal" airplane is produced on this assumption. Lastly, detailed suggestions are given on the possibilities of application of this method of calculation. It especially simplifies the design and evaluation of structural changes and the determination of the limits of technical possibilities. The present report deals only with the relations of the airfoils. The mutual action of the airfoils, engine and propeller will be treated in a subsequent report.
Date: March 1928
Creator: Schrenk, Martin
Partner: UNT Libraries Government Documents Department
open access

The "Gloster IV" Seaplane (British)

Description: Circular describing the Glouster IV, which is a biplane designed for high maximum speeds. A description of the components, design, controls, performance, drawings, and photographs are provided.
Date: March 1928
Partner: UNT Libraries Government Documents Department
open access

Motion of Fluids With Very Little Viscosity

Description: Report presenting a discussion of the laws of motion of a fluid with very low viscosity. Mathematical formulas that have been created in order to compensate for this lack of viscosity and the circumstances under which viscosity can be disregarded are provided.
Date: March 1928
Creator: Prandtl, L.
Partner: UNT Libraries Government Documents Department
open access

Resistance of streamline wires

Description: "This note contains the results of tests to determine the resistance of four sizes of streamline wire. The investigation was conducted in the six-inch wind tunnel of the National Advisory Committee for Aeronautics. The tests were made at various velocities and it was found that the resistance of streamline wires was considerably less than that of round wires of equivalent strength. Scale effect was also found since, with an increase of Reynolds Number, a decrease in the resistance coefficient was obtained" (p. 1).
Date: March 1928
Creator: DeFoe, George L.
Partner: UNT Libraries Government Documents Department
Back to Top of Screen