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open access

Test of a Dual-Rotation Axial-Flow Fan

Description: Report presenting a dual-rotation axial-flow fan composed of two oppositely rotating 24-blade rotors. The fan was tested with various combinations of front and rear blade angles and with two combinations of front and rear solidities. For quantity coefficients above 0.3 the greatest pressure rise was obtained from 24 blades in each rotor with the blades adjusted to absorb equal torque at maximum pressure.
Date: December 1942
Creator: Bell, E. Barton & DeKoster, Lucas J.
open access

The Porpoising Characteristics of a Planing Surface Representing the Forebody of a Flying-Boat Hull

Description: Porpoising characteristics were observed on V-body fitted with tail surfaces for different combinations of load, speed, moment of inertia, location of pivot, elevator setting, and tail area. A critical trim was found which was unaltered by elevator setting or tail area. Critical trim was lowered by moving pivot either forward or down or increasing radius or gyration. Increase in mass and moment of inertia increased amplitude of oscillations. Complete results are tabulated and shown graphically.
Date: May 1942
Creator: Benson, James M.
open access

An Investigation of Hydrofoils in the NACA Tank 1: Effect of Dihedral and Depth of Submersion

Description: Tests were conducted on hydrofoil assemblies approximating an arrangement for use under seaplanes or surface boats. A series of hydrofoils, each supported by two struts, was towed at various depths ranging from partial submersions to a depth of 5-chord lengths. At depths greater than 4 or 5 chords, the influence of the surface of the water is small; hydrofoils operating at low speed will have characteristics similar to those of airfoils of the same section.
Date: September 1942
Creator: Benson, James M. & Land, Norman S.
open access

The effect of dead rise upon the low-angle type of porpoising

Description: Report presenting data pertaining to forces and moments developed by V-bottom planing surfaces of different angles of dead rise in order to compute the effect of dead rise on the lower trim limit of stability on a seaplane. Increase of angle of dead rise in the range of 10 degrees to 30 degrees causes an important increase in the lower limit of stability.
Date: October 1942
Creator: Benson, James M. & Lina, Lindsay J.
open access

Diagrams for Calculation of Airfoil Lattices

Description: "The field for curved blades is represented by a vortex series with a vortex removed at the blade point. Further, an example of calculation of a curved blade from this series is given, whereby the necessary accuracy required of the different methods in practice is shown according to the case considered" (p. 1).
Date: July 1942
Creator: Betz, Albert
open access

Effect of additions of aromatics on the knocking characteristics of several 100-octane fuels at two engine speeds

Description: Report presenting testing at two engine speeds on six representative fuels rated at 100-octane number by the C.F.R. aviation method. Blends of the fuels with benzene, toluene, xylene, and isopropyl comprise nine other fuels, leading to testing on 15 fuels. Results regarding the tests at 2000 rpm and 250 degrees Fahrenheit inlet-air temperature, at 3100 rpm and 250 degrees Fahrenheit inlet-air temperature, 2000 rpm and 150 degrees Fahrenheit inlet-air temperature, and 3100 rpm and 150 degrees Fa… more
Date: May 1942
Creator: Biermann, Arnold E.; Corrington, Lester C. & Harries, Myron L.
open access

Wind-Tunnel Tests of Four- and Six-Blade Single- and Dual-Rotating Tractor Propellers

Description: "Test of 10-foot diameter, four and six blade single-rotating and dual-rotating propellers were conducted in the NACA propeller-research tunnel. The propellers were mounted at the front end of a streamline body incorporating spinners to house the hub portions. The effect of a symmetrical wing mounted in the slipstream ranged from 20 degrees to 65 degrees setting corresponds to airplane speeds greater than 500 miles per hour. The results indicate that dual-rotating propellers were from 0 to 6 pe… more
Date: July 13, 1942
Creator: Biermann, David & Hartman, Edwin P.
open access

Wind-tunnel tests of single- and dual-rotating tractor propellers of large blade width

Description: Report presenting tests of 10-foot diameter, single- and dual-rotating tractor propellers with two to eight blades conducted in the 20-foot propeller-research tunnel. The blades were 50 percent wider than those used in previous investigations. Results regarding the effect of dual rotation and effect of solidity are provided.
Date: September 1942
Creator: Biermann, David; Gray, W. H. & Maynard, Julian D.
open access

The Formation of Ice on Aircraft

Description: "The phenomenon accompanying the formation of ice on aircraft has been frequently discussed. The consequences of ice formation have been briefly analyzed in an article , but a definite physical solution of the problem has not been reached up to the present. Most of the authors agree that subcooled water droplets play a prominent part, but they fail to specify the exact manner in which this occurs" (p. 1).
Date: August 1942
Creator: Bleeker, W.
open access

Contribution to the Design of Plywood Shells

Description: "The writer sets out to prove by calculation and experiment that by extensive utilization of the skin to carry axial load (reduction of stringer spacing) the stringer sections can be made small enough to afford a substantial saving in structural weight. This saving ranges from 5 to about 40 percent" (p. 1).
Date: October 1942
Creator: Blumrich, S.
open access

Interaction of Be with Fission Neutrons

Description: To determine whether or not the (n,2n) reaction in Be would produce a net increase in fission neutrons in a power plant, the distribution of In resonance neutrons slowed down from fission energies in a graphite block was measured with and without a 2" of Be in front of a U3O8 slab undergoing fission. The thermal neutrons producing the fissions were obtained by slowing down neutrons from a cyclotron source. The observed distribution without Be was well represented by a Gaussian source range 36 c… more
Date: April 29, 1942
Creator: Borst, L.; Allison, S. K.; Wheeler, John Archibald, 1911-2008 & Weinberg, Alvin Martin, 1915-2006
open access

Radiation Problems of the Chemical Plant

Description: "Absorption measurements have been made in a large body of water to evaluate the contribution to the radiation intensity produced by the degradation of radiation without absorption. Radiation intensities three times those expected from a simple exponential absorption were found. Scattering from the air of gamma radiation has been measured and has been found to agree satisfactorily with theoretical predictions. The penetration of radiation through curved pipes in shielding has been measured and … more
Date: December 12, 1942
Creator: Borst, Lyle B. & Wollan, Ernest Omar
open access

An Experimental Investigation of Flow Across Tube Banks

Description: Flow across tube banks was investigated by surveys of total dynamic and static pressure by visualization of the flow through the use of titanium tetrachloride smoke, by thermocouple surveys of heated tubes, and by hot-wire surveys of both heated and unheated tubes. It was found that turbulence increased as the depth of the bank increased and that the broad wake behind each tube affected flow over the succeeding tubes.
Date: March 1942
Creator: Brevoort, M. J. & Tifford, A. N.
open access

Generalized selection charts for bombers powered by one, two, four, and six 2000-horsepower engines

Description: Report presenting a study of the performance of bombers powered by one, two, four, and six 2000-horsepower engines supercharged to 25,000 feet. The performances are computed and are based on drag coefficients equal to the best obtained on modern airplanes and on weight estimates obtained from modern Army Air Forces airplanes. A chart is provided with the coordinates of power loading and wing loading noted so that all performances can be compared.
Date: July 1942
Creator: Brevoort, M. J.; Stickle, G. W. & Hill, Paul R.
open access

Effect of airplane design efficiency and engine economy on range

Description: Report presenting an examination of the effects of variations in efficiency parameters, including engine economy, aerodynamic efficiency, and structural efficiency, on airplane performance. Efficiency parameters were found to be extremely ineffective in adjusting the airplane performance to its tactical mission as compared to primary parameters like altitude, power, gross weight, and wing area.
Date: December 1942
Creator: Brevoort, Maurice J.; Stickle, George W. & Hill, Paul R.
open access

Generalized selection charts for bombers powered by one, two, four, and six 3000-horsepower engines 1: capacity and economy

Description: Supplement using data from a previous report to show the cargo that can be carried at various ranges, pounds of cargo that can be carried per pound of fuel, and other graphs to simplify the problem of determining which cargo can be carried at any range. The assumptions, parameters, and equations from the original report are carried over in the supplement.
Date: August 1942
Creator: Brevoort, Maurice J.; Stickle, George W. & Hill, Paul R.
open access

Generalized selection charts for bombers powered by two, four, and six 3000-horsepower engines

Description: Report presenting a study of the performance of bombers powered by two, four, and six 3000-horsepower engines supercharged to 35,000 feet. The performances are computed and are based on drag coefficients equal to the best obtained on modern airplanes and on weight estimates obtained from modern Army Air Forces airplanes. A chart is provided with the coordinates of power loading and wing loading noted so that all performances can be compared.
Date: August 1942
Creator: Brevoort, Maurice J.; Stickle, George W. & Hill, Paul R.
open access

Generalized selection charts for bombers with four 2000-horsepower engines

Description: Report presenting a study of the performance of bombers powered by four 2000-horsepower engines supercharged to 25,000 feet. A series of charts is provided with the coordinates of power loading and wing loading in order to simplify the selection of the best airplane for a given purpose.
Date: May 1942
Creator: Brevoort, Maurice J.; Stickle, George W. & Hill, Paul R.
open access

Graphical representation of intercooler parameters and performance at altitudes from 25,000 to 60,000 feet

Description: From Summary: "Interdependence of intercooler parameters and performance for a pursuit-type airplane using a 1675-horsepower engine is shown at altitudes of 25,000, 36,000, 47,000, and 60,000 feet by means of perspective drawings. Qualitatively, the drawings have general application. Intercooling between stages of supercharging at high altitudes results in no saving in the power to supercharge and cool the engine air."
Date: November 1942
Creator: Brimley, D. E.
open access

Progress Summary Number 1: Mechanical Properties of Flush-Riveted Joints Submitted by Five Airplane Manufacturers

Description: Summary presenting information on flush-riveted joints for aircraft construction, including the strength, occurrence of defects, and effect of the angle of rivet head. The current tests covers specimens from 15 manufacturers of which 5 series have been completed and are described in this report.
Date: February 1942
Creator: Brueggeman, William Charles
open access

Analytical Theory of the Campini Propulsion System

Description: "The present report deals exclusively with the particular jet-propulsion system mentioned in the cited reports. The discussion is limited, for the present, to the analytical study of the efficiency and the consumption for the case of application to aircraft and to the plotting of the practical operating curves secured theoretically by the use of suitable experimental factors" (p. 1).
Date: March 1942
Creator: Campini, S.
open access

Shear-lag tests of two box beams with flat covers loaded to destruction

Description: "Strain-gage tests were made on two box beams loaded to destruction in an attempt to verify the shear-lag theory at stresses beyond the yield point. The test results indicated that the corner-flange stresses can be predicted with a fair degree of accuracy. Collapse of both beams was precipitated by failure of the corner angles at stresses close to the column yield stress of the material" (p. 1).
Date: October 1942
Creator: Chiarito, Patrick T.
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