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Calibration and lag of a Friez type cup anemometer

Description: "Tests on a Friez type cup anemometer have been made in the variable density wind tunnel of the Langley Memorial Aeronautical Laboratory to calibrate the instrument and to determine its suitability for velocity measurements of wind gusts. The instrument was calibrated against a Pitot-static tube placed directly above the anemometer at air densities corresponding to sea level, and to an altitude of approximately 6000 feet. Air-speed acceleration tests were made to determine the lag in the instru… more
Date: June 1930
Creator: Pinkerton, Robert M.
open access

Contribution to the Theory of Propeller Vibrations

Description: This report presents a calculation of the torsional frequencies of revolving bars with allowance for the air forces. Calculation of the flexural or bonding frequencies of revolving straight or tapered bars in terms of the angular velocity of revolution. Calculation on the basis of Rayleigh's principle of variation. There is also a discussion of error estimation and the accuracy of results. The author then provides an application of the theory to screw propellers for airplanes and the discusses … more
Date: June 1930
Creator: Liebers, F.
open access

Identification of Aircraft Tubing by Rockwell Test

Description: A large number of tests were made on tubes of 1025 and 4130X steel, in various diameters and wall thicknesses, and after diverse heat treatments. The Rockwell B scale was employed, as being the best suited to the ranges of hardness encountered. Only satisfactory chrome molybdenum tubes were found to show a hardness in excess of 90-B after normalizing.
Date: June 1930
Creator: Knerr, Horace
open access

Identification of Aircraft Tubing by Rockwell Test

Description: Seamless steel tubing is today the principal material of construction for aircraft. The commercial grade of tubing containing about 0.10 to 0.20% carbon at first used is being superseded by two grades which are approved by the army and navy, and which are also becoming standard for commercial airplanes.
Date: June 1930
Creator: Knerr, Horace
open access

Performance of a high-speed compression-ignition engine using multiple orifice fuel injection nozzles

Description: This report presents test results obtained at the Langley Memorial Aeronautical Laboratory of the National Advisory Committee for Aeronautics during an investigation to determine the relative performance of a single-cylinder, high-speed, compression-ignition engine when using fuel injection valve nozzles with different numbers, sizes, and directions of round orifices. A spring-loaded, automatic injection valve was used, centrally located at the top of a vertical disk-type combustion chamber for… more
Date: June 1930
Creator: Spanogle, J. A. & Foster, H. H.
open access

A Possible Method for Preventing the Autorotation of Airplane Wings

Description: "At the suggestion of Professor Betz, the following device was tested with the object of reducing the autorotational speed of airplane wings. The model of a normal wing with the Gottigen profile 420, 1 meter span and 0.2 meter chord was provided with a pair of symmetrical slots on the suction side, connected with each other inside the wing. The arrangement of the testing equipment and models are given and the effect of the slots can be seen in the experimental curves that are included" (p. 1).
Date: June 1930
Creator: Schrenk, Oskar
open access

Propulsion by Reaction

Description: This report concerns propulsion by means of rockets. The author concerns himself mainly with efficiency of propulsion and he defines and mathematically expresses those efficiencies.
Date: June 1930
Creator: Roy, Maurice
open access

Strength in Shear of the Thin Curved Sheets of Alclad

Description: "This note is on an investigation made to obtain information on the strength of thin curved sheets of Alclad in shear. Designers may utilize this material as a strength member as well as for a covering for the wings and fuselages. A reduction may then be made in the size of the internal strength members. These experiments were undertaken with the object of securing the maximum value from the metal in this respect" (p. 1).
Date: June 1930
Creator: Smith, George Michael
open access

Maneuverability investigation of the F6C-3 airplane with special flight instruments

Description: "This investigation was made for the purpose of obtaining information on the maneuverability of the F6C-3 airplane. It is the first of a series of similar investigations to be conducted on a number of military airplanes for the purpose of comparing the abilities of these airplanes to maneuver, and also to establish a fund of quantitative data which may be used in formulating standards of comparison for rating the maneuverability of any airplane. A large part of this initial investigation was ne… more
Date: May 23, 1930
Creator: Dearborn, C. H. & Kirschbaum, H. W.
open access

Pressure Distribution Over a Thick, Tapered and Twisted Monoplane Wing Model-N.A.C.A. 81-J

Description: "This reports presents the results of pressure distribution tests on a thick, tapered and twisted monoplane wing model. The investigation was conducted for the purpose of obtaining data on the aerodynamic characteristics of the new wing and to provide additional information suitable for use in the design of tapered cantilever wings. The tests included angles of attack up to 90 degrees. The span loading over the wing was approximately of elliptical shape, which gave rise to relatively small bend… more
Date: May 21, 1930
Creator: Wenzinger, Carl J.
open access

Dynamic and flight tests on rubber-cord and oleo-rubber-disk landing gears for an F6C-4 airplane

Description: The investigation described in this report was conducted for the purpose of comparing an oleo-rubber-disk and a rubber-cord landing gear, built for use on an F6C-4 airplane. The investigation consisted of drop tests under various loading conditions and flight tests on an F6C-4 airplane. In the drop tests the total work done on each gear and the work done on each of the shock-absorbing units were determined. For both drop tests and flight tests the maximum loads and accelerations were determined… more
Date: May 20, 1930
Creator: Peck, William C.
open access

Pressure Fluctuations in a Common-Rail Fuel Injection System

Description: This report presents the results of an investigation to determine experimentally the instantaneous pressures at the discharge orifice of a common-rail fuel injection system in which the timing valve and cut-off valve were at some distance from the automatic fuel injection valve, and also to determine the methods by which the pressure fluctuations could be controlled. The results show that pressure wave phenomena occur between the high-pressure reservoir and the discharge orifice, but that these… more
Date: May 20, 1930
Creator: Rothrock, A. M.
open access

Balanced and Servo Control Surfaces

Description: "Many reports on various control systems are available, but the results cannot be generally applied since the effect of particular changes of surface-form and mounting are subject to variations depending upon airfoil section and influences of airplane layout. This report presents a simple analysis of several control systems in more general use. Elevators, ailerons, and rudders are all discussed" (p. 1).
Date: May 1930
open access

Development of the Junkers-Diesel Aircraft Engine

Description: The working process of the Junkers engine has resulted from a series of attempts to attain high performance and to control the necessarily rapid and complete combustion at extremely high speeds. The two main problems of Diesel engines in aircraft are addressed; namely, incomplete combustion and the greater weight of Diesel engine parts compared to gasoline engines.
Date: May 1930
Creator: Gasterstädt
open access

Experimental Research on the Friction of Pivots

Description: In horology the friction between solids is of the greatest importance; one limited, however, to the application of the laws of Coulomb which, do not at all correspond with reality. This report presents a review of the subject and some general conclusions. The choice of lubricant is discussed as well as the pressure between frictional surfaces. The gears in a watch are used extensively as examples.
Date: May 1930
Creator: Jaquerod, A.; Defossez, L. & MĂ¼geli, H
open access

Full Scale Drag Tests on Various Parts of Fairchild (FC-2W2) Cabin Monoplane

Description: "The drag due to the various parts of a Fairchild (FC-2W2) cabin monoplane was measured at air speeds varying from 50 to 100 m.p.h., in the Twenty-Foot Propeller Research Tunnel of the National Advisory Committee for Aeronautics. It was found that the largest drag was due to the radial air-cooled engine. The measured drag due to the landing gear was also large, being about 4/5 of that due to the engine" (p. 1).
Date: May 1930
Creator: Herrnstein, William H., Jr.
open access

The Magnus Effect in Theory and in Reality

Description: A discussion of the Flettner rotor is presented from a nautical and economic viewpoint, and although it was a failure, the experimental and theoretical inventions cannot be disregarded. The following critical and experimental investigation will show the relations and applicability of the theories and practical applications. The Magnus effect is described in detail and a discussion and critical review of the Magnus effect is included.
Date: May 1930
Creator: Ahlborn, F.
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