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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.
Item Type: Refine your search to only Report
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Considerations on Propeller Efficiency

Description: The propeller cannot be considered alone, but the mutual interference between propeller and airplane must be considered. These difficulties are so great when the joint action of propeller and airplane is considered, that the aerodynamic laboratory at Gottingen originally abandoned the idea of applying the efficiency conception of the test results. These difficulties and the methods by which they are overcome are outlined in this report.
Date: September 1928
Creator: Betz, A.
Item Type: Refine your search to only Report
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Contribution to the Systematic Investigation on Joukowsky Profiles

Description: "This article resulted from the need of showing, in a simple way, how the aerodynamic properties of airfoils are affected by the shape of their profiles. No general solution of this problem could be found, since the profile shapes cannot ordinarily be expressed by simple mathematical formulas. This advantage is possessed only by the Joukowsky profiles and this discussion of the problem is therefore limited to them" (p. 1).
Date: April 1928
Creator: Loew, Gottfried
Item Type: Refine your search to only Report
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Corrosion Embrittlement of Duralumin I: Practical Aspects of the Problem

Description: Since aircraft design is tending toward all-metal construction, the strong heat-treatable light aluminum alloy, duralumin (a generic name for a class of heat-treatable alloys containing Cu, Mg, Mn, and Si), is finding increasing application. Doubt has been expressed concerning the reliability and permanence of these materials. Information is given on the effect of corrosion on the tensile properties of 14-gauge sheet duralumin, heat treated by quenching in hot water after being heated for 15 mi… more
Date: April 1928
Creator: Rawdon, Henry S.
Item Type: Refine your search to only Report
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Corrosion Embrittlement of Duralumin II: Accelerated Corrosion Tests and the Behavior of High-Strength Aluminum Alloys of Different Compositions

Description: The permanence, with respect to corrosion, of light aluminum alloy sheets of the duralumin type, that is, heat-treatable alloys containing Cu, Mg, Mn, and Si is discussed. Alloys of this type are subject to surface corrosion and corrosion of the interior by intercrystalline paths. Results are given of accelerated corrosion tests, tensile tests, the effect on corrosion of various alloying elements and heat treatments, electrical resistance measurements, and X-ray examinations.
Date: April 1928
Creator: Rawdon, Henry S.
Item Type: Refine your search to only Report
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Corrosion Embrittlement of Duralumin III: Effect of the Previous Treatment of Sheet Material on the Susceptibility to This Type of Corrosion

Description: As a result of testing, it was determined that control of the rate of quenching and the avoidance of accelerated aging by heating are the only means of modifying duralumin itself so as to minimize the intercrystalline form of corrosive attack. It is so simple a means that it should be adopted even though it may not completely prevent, but only reduce, this form of corrosive attack. By so doing, the need for protection of the surface is less urgent.
Date: April 1928
Creator: Rawdon, Henry S.
Item Type: Refine your search to only Report
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Corrosion Embrittlement of Duralumin IV: The Use of Protective Coatings

Description: Although the corrosion resistance of sheet duralumin can be greatly improved by suitable heat treatment, protection of the surface is still necessary if long life under varied service conditions is to be insured. The coatings used for this purpose may be grouped into three classes: the varnish type of coating, the oxide type produced by a chemical treatment of the surface, and metallic coatings, of which aluminum appears to be the most promising. Since the necessary weather exposure tests are n… more
Date: April 1928
Creator: Rawdon, Henry S.
Item Type: Refine your search to only Report
open access

Crank Case Scavenging of a Two-Stroke-Cycle Engine

Description: "Experiments with a two-stroke-cycle, crank case scavenging engine. Effect of systematic variation of the height of the scavenge and exhaust ports on the scavenging, as determined by gas analysis. The best results were obtained under conditions differing from the usual ones" (p. 1).
Date: January 1928
Creator: Holm, Otto
Item Type: Refine your search to only Report
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A Dangerous Seaplane Landing Condition

Description: "A peculiar phenomena in seaplane landing is observed and reported. The seaplane having executed a normal fast landing at low incidence, a forward movement of the control stick effected an unusual condition in that the seaplane left the water suddenly in an abnormal attitude. The observations describing this phenomena are offered as a warning against possible accident and as a conjectural cause of seaplane landing accidents of a certain kind" (p. 1).
Date: May 1928
Creator: Carroll, Thomas
Item Type: Refine your search to only Report
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Determination of Propeller Deflection by Means of Static Load Tests on Models

Description: "This note describes a simple and inexpensive method for determining the deflection of propeller blades under operating loads. Both the centrifugal force and air force loads are applied statically as a number of concentrated loads by means of weights and wires. Two methods of attaching the wires to the propeller blades have been tested, both giving approximately the same deflections. The method is considered useful for studying the deflections of propellers of different shapes under various ope… more
Date: January 1928
Creator: Weick, Fred E.
Item Type: Refine your search to only Report
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The Determination of Several Spray Characteristics of a High-Speed Oil Engine Injection System with an Oscilloscope

Description: An investigation was conducted to determine the injection lag, duration of injection, and spray start and cut-off characteristics of a fuel injection system operated on an engine and injecting fuel into the atmosphere. The results indicated that for the injection system investigated, the injection lag, in crank degrees, decreased with increase in engine speed for a constant quantity of fuel discharged, but was not affected at constant engine speed by varying the fuel quantity from approximately… more
Date: September 1928
Creator: Hicks, Chester W. & Moore, Charles S.
Item Type: Refine your search to only Report
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Determination of the Air Forces and Moments Produced by the Ailerons of an Airplane

Description: As a rule, the actual lift distribution at the wing tips shows deviations from the theoretical distribution, so that an approximate evaluation of the distribution may be regarded as satisfactory. After a few brief remarks on the fundamentals of the exact computation, the method will be so presented that the lift distribution for deflected ailerons may be determined for other values of the parameter p from the results already obtained. Coefficients will then be given in the form of diagrams and … more
Date: November 1928
Creator: Wieselberger, C. & Asano, T.
Item Type: Refine your search to only Report
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The Diesel as a Vehicle Engine

Description: The thorough investigation of a Dorner four-cylinder, four-stroke-cycle Diesel engine with mechanical injection led me to investigate more thoroughly the operation of the Diesel as a vehicle engine. Aside from the obvious need of reliability of functioning, a high rotative speed, light weight and economy in heat consumption per horsepower are also indispensable requirements.
Date: June 1928
Creator: Neumann, Kurt
Item Type: Refine your search to only Report
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Differential Pressures on a Pitot-Venturi and a Pitot-Static Nozzle Over 360 Degrees Pitch and Yaw

Description: "Measurements of the differential pressures on two navy air-speed nozzles, consisting of a Zahm type Pitot-Venturi tube and a SQ-16 two-pronged Pitot-static tube, in a tunnel air stream of fixed speed at various angles of pitch and yaw between 0 degrees and plus or minus 180 degrees. This shows for a range over -20 degrees to +20 degrees pitch and yaw, indicated air speeds varying very slightly over 2 per cent for the Zahm type and a maximum of about 5 per cent for the SQ-16 type from the calib… more
Date: 1928
Creator: Bear, R. M.
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 - 1

Description: "This report presents the results of an investigation undertaken in the 20-foot Propeller Research Tunnel at Langley Field on the cowling of radial air-cooled engines. A portion of the investigation has been completed, in which several forms and degrees of cowling were tested on Wright "Whirlwind" J-5 engine mounted in the nose of a cabin fuselage. The cowlings varied from the one extreme of an entirely exposed engine to the other in which the engine was entirely inclosed. Cooling tests were ma… more
Date: October 5, 1928
Creator: Weick, Fred E.
Item Type: Refine your search to only Report
open access

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
open access

The Drag of a J-5 Radial Air-Cooled Engine

Description: This note describes tests of the drag due to a Wright "Whirlwind" (J-5) radial air-cooled engine mounted on a cabin type airplane. The tests were made in the 20-foot Propeller Research Tunnel of the National Advisory Committee for Aeronautics. The drag was obtained with three different types of exhaust stacks: Short individual stacks, a circular cross section collector ring, and a streamline cross section collector ring.
Date: July 1928
Creator: Weick, Fred E.
Item Type: Refine your search to only Report
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