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open access

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

The Gaseous Explosive Reaction: The Effect of Pressure on the Rate of Propagation of the Reaction Zone and Upon the Rate of Molecular Transformation

Description: This study of gaseous explosive reaction has brought out a number of important fundamental characteristics of the explosive reaction indicating that the basal processes of the transformation are much simpler and corresponds more closely to the general laws and principles of ordinary transformations than is usually supposed. The report calls attention to the point that the rate of molecular transformation within the zone was found in all cases to be proportional to pressure, that the transformat… more
Date: June 14, 1930
Creator: Stevens, F. W.
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
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