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Cooperative Measurements of Radio Fading in 1925

Description: Scientific paper issued by the Bureau of Standards over studies conducted on radio fading. As stated in the abstract, "the series of measurements on fading were devoted to studies of fading effects during the sunset period, effects during the solar eclipse of January 24, the fading variations throughout a 24-hour day, and the effects of high transmitting power on fading" (p. 419). This paper includes tables, maps, illustrations, and photographs.
Date: August 17, 1927
Creator: Dellinger, J. H.; Jolliffe, C. B. & Parkinson, T.
Item Type: Refine your search to only Report
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Drag and Cooling With Various Forms of Cowling for A "Whirlwind" Radial Air-Cooled Engine - 2

Description: "This report gives the results of the second portion of an investigation in the twenty-foot Propeller Research Tunnel of the National Advisory Committee for Aeronautics, on the cowling and cooling of a "Whirlwind" J-5 radial air-cooled engine. The first portion pertains to tests with a cabin fuselage. This report covers tests with several forms of cowling, including conventional types, individual fairings behind the cylinders, individual hoods over the over the cylinders, and the new N. A. C. A… more
Date: December 17, 1928
Creator: Weick, Fred E.
Item Type: Refine your search to only Report
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Flow and Force Equations for a Body Revolving in a Fluid

Description: Part I gives a general method for finding the steady-flow velocity relative to a body in plane curvilinear motion, whence the pressure is found by Bernoulli's energy principle. Integration of the pressure supplies basic formulas for the zonal forces and moments on the revolving body. Part II, applying this steady-flow method, finds the velocity and pressure at all points of the flow inside and outside an ellipsoid and some of its limiting forms, and graphs those quantities for the latter forms.… more
Date: December 17, 1928
Creator: Zahm, A. F.
Item Type: Refine your search to only Report
open access

Tables for pressure of air on coming to rest from various speeds

Description: From Summary: "In Technical Report no. 247 of the National Advisory Committee for Aeronautics theoretical formulas are given from which was computed a table for the pressure of air on coming to rest from various speeds, such as those of aircraft and propeller blades. In that report, the table gave incompressible and adiabatic stop pressures of air for even-speed intervals in miles per hour and for some even-speed intervals in knots per hour. Table II of the present report extends the above-ment… more
Date: December 17, 1928
Creator: Zahm, A. F. & Louden, F. A.
Item Type: Refine your search to only Report
open access

Full-scale turning characteristics of the U.S.S. Los Angeles

Description: This paper present a description of the method employed and results obtained in full-scale turning trials on the rigid airship U. S. S. "Los Angeles". The results of this investigation are not sufficiently comprehensive to permit definite conclusions as to the variation of turning characteristics with changes in speed and rudder angle. They indicate however, that the turning radius compares favorably with that for other large airships, that the radius is independent of the speed, that the posit… more
Date: April 17, 1929
Creator: Thompson, F. L.
Item Type: Refine your search to only Report
open access

Relation of Hydrogen and Methane to Carbon Monoxide in Exhaust Gases From Internal-Combustion Engines

Description: The relation of hydrogen and methane to carbon monoxide in the exhaust gases from internal-combustion engines operating on standard-grade aviation gasoline, fighting-grade aviation gasoline, hydrogenated safety fuel, laboratory diesel fuel, and auto diesel fuel was determined by analysis of the exhaust gases. Two liquid-cooled single-cylinder spark-ignition, one 9-cylinder radial air-cooled spark-ignition, and two liquid-cooled single-cylinder compression-ignition engines were used.
Date: August 17, 1933
Creator: Gerrish, Harold C. & Tessmann, Arthur M.
Item Type: Refine your search to only Report
open access

An Aerodynamic Analysis of the Autogiro Rotor With a Comparison Between Calculated and Experimental Results

Description: This report presents an extension of the autogiro theory of Glauert and Lock in which the influence of a pitch varying with the blade radius is evaluated and methods of approximating the effect of blade tip losses and the influence of reversed velocities on the retreating blades are developed. A comparison of calculated and experimental results showed that most of the rotor characteristics could be calculated with reasonable accuracy, and that the type of induced flow assumed has a secondary ef… more
Date: January 17, 1934
Creator: Wheatley, John B.
Item Type: Refine your search to only Report
open access

Tests of nacelle-propeller combinations in various positions with reference to wings 4: thick wing - various radial-engine cowlings - tandem propellers

Description: This report is the fourth of a series giving the results obtained from wind tunnel tests to determine the interference lift and drag and propulsive efficiency of wing-nacelle-propeller combinations. Previous reports give the results of tests with tractor propellers with various forms of nacelles and engine cowlings. This report gives the results of tests of tandem arrangements of engines and propellers in 11 positions with reference to a thick wing.
Date: January 17, 1934
Creator: McHugh, James G.
Item Type: Refine your search to only Report
open access

Noise From Two-Blade Propellers

Description: "The two-blade propeller, one of the most powerful sources of sound known, has been studied with the view of obtaining fundamental information concerning the noise emission. In order to eliminate engine noise, the propeller was mounted on an electric motor. A microphone was used to pick up the sound whose characteristics were studied electrically. The distribution of noise throughout the frequency range, as well as the spatial distribution about the propeller, was studied. The results are given… more
Date: January 17, 1935
Creator: Stowell, E. Z. & Deming, A. F.
Item Type: Refine your search to only Report
open access

A Theory for Primary Failure of Straight Centrally Loaded Columns

Description: "A theory of primary failure of straight centrally loaded columns is presented. It is assumed that the column cross section and the load are constant throughout the length. Primary failure is defined as any type of failure in which the cross sections are translated, rotated, or translated and rotated but not distorted in their own planes" (p. 141).
Date: August 17, 1936
Creator: Lundquist, Eugene E. & Fligg, Claude M.
Item Type: Refine your search to only Report
open access

An Analysis of Lateral Stability in Power-Off Flight With Charts for Use in Design

Description: "The aerodynamic and mass factors governing lateral stability are discussed and formulas are given for their estimation. Relatively simple relationships between the governing factors and the resulting stability characteristics are presented. A series of charts is included with which approximate stability characteristics may be rapidly estimated" (p. 1).
Date: November 17, 1936
Creator: Zimmerman, Charles H.
Item Type: Refine your search to only Report
open access

The experimental and calculated characteristics of 22 tapered wings

Description: From Summary: "The experimental and calculated aerodynamic characteristics of 22 tapered wings are compared, using tests made in the variable-density wind tunnel. The wings had aspect ratios from 6 to 12 and taper ratios from 1:6:1 and 5:1. The compared characteristics are the pitching moment, the aerodynamic-center position, the lift-curve slope, the maximum lift coefficient, and the curves of drag. The method of obtaining the calculated values is based on the use of wing theory and experiment… more
Date: November 17, 1937
Creator: Anderson, Raymond F.
Item Type: Refine your search to only Report
open access

Pressure distribution over an NACA 23012 airfoil with a slotted and a plain flap

Description: Report presents the results of pressure-distribution of an NACA 23012 airfoil equipped with a slotted flap and with a plain flap conducted in the 7 by 10-foot wind tunnel. A test installation was used in which the 7-foot-span airfoil was mounted vertically between the upper and lower sides of the closed test section so that two-dimensional flow was approximated. The pressures were measured on the upper and lower surfaces at one chord section both on the main airfoil and on the flaps for several… more
Date: March 17, 1938
Creator: Wenzinger, Carl J. & Delano, James B.
Item Type: Refine your search to only Report
open access

The effect of nacelle-propeller diameter ratio on body interference and on propeller and cooling characteristics

Description: Report presents the results of an investigation conducted in the NACA 20-foot tunnel to determine the slipstream drag, the body interference, and the cooling characteristics of nacelle-propeller diameter. Four combinations of geometrically similar propellers and nacelles, mounted on standard wing supports, were tested with values of the ratio of nacelle diameter to propeller diameter of 0.25, 0.33, and 0.44.
Date: April 17, 1939
Creator: McHugh, James G. & Derring, Eldridge H.
Item Type: Refine your search to only Report
open access

A simplified theoretical method of determining the characteristics of a lifting rotor in forward flight

Description: Theoretical derived expressions for the flapping, the thrust, the torque, and the profile drag-lift ratio of nonfeathering rotor with hinged, rectangular, linearly twisted blades are given as simple functions of the inflow velocity and the blade pitch. Representative values of the coefficients of each of the terms in these expressions are tabulated for a series of specified values of the tip-speed ratio. Analysis indicates that the tabulated values can be used to calculate, with reasonable accu… more
Date: March 17, 1941
Creator: Bailey, F. J., Jr.
Item Type: Refine your search to only Report
open access

Wind-Tunnel Investigation of an NACA 23012 Airfoil With 30 Percent-Chord Venetian-Blind Flaps

Description: Report presents the results of an investigation made in the NACA 7 by 10-foot wind tunnel of a NACA 23012 airfoil with 30-percent-chord venetian-blind flaps having one, two, three, and four slats of Clark y section. The three-slat arrangements was aerodynamically the best of those tested but showed practically no improvement over the comparable arrangement used in the preliminary tests published in NACA Technical Report No. 689. The multiple-slat flaps gave slightly higher lift coefficients tha… more
Date: September 17, 1941
Creator: Rogallo, F. M. & Spano, Bartholomew S.
Item Type: Refine your search to only Report

Newsmap. Monday, August 17, 1942 : week of August 7 to August 14

Description: Front: Text describes action on various war fronts: Solomon Islands, New Guinea, Aleutians, China, India, Western Europe, Yugoslavia, Mediterranean, Russia. Large world map is keyed to text and illustrates time zones around the world. Map insets show Solomon Islands, Russian front. Includes photographs: view of Tulagi; German fighter; Facing the Nazis; Sniper suit; A traitor covers up; Club for U.S. forces on London. Back: British Battle Dress. Includes 6 photograhs, 4 drawings with accomp… more
Date: August 17, 1942
Creator: [United States]. Army Orientation Course.
Item Type: Refine your search to only Poster
open access

Production of Uranium Metal

Description: Experiments were carried out for the purpose of increasing production, efficiency, and purity of uranium metal. The electrolytic method as described by Driggs and Lilliendahl for the preparation of uranium metal was followed with but little deviation. The yield of metal at the very best was only 50%. The metal powder produced, at times, was very pyrophoric. Methods were found whereby the metal, at least in part, can be made from the oxides with an average yield of about 90%. The small amounts o… more
Date: February 17, 1943
Creator: Nagy, R.
Item Type: Refine your search to only Report
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