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  Partner: UNT Libraries Government Documents Department
 Decade: 1930-1939
 Year: 1938
 Collection: National Advisory Committee for Aeronautics Collection
N.A.C.A. Stall-Warning Device

N.A.C.A. Stall-Warning Device

Date: February 1, 1938
Creator: Thompson, F.L.
Description: With some airplanes the approach to the stall is accompanied by changes in the behavior, such as tail buffeting or changes in the control characteristics of the airplane so that the pilot obtains a warning of the impending stall. Vith other airplanes it is possible to approach the stall without any perceptible warning other than the reading of the air-speed meter, in which case the danger of inadvertent stalling is considerably greater. Although it is not within the scope of this paper to discuss stalling characteristics, it is desired to point out that in general the danger of inadvertent stalling is greatest with those airplanes that behave worse when the stalling occurs; that is, with airplanes in which the stall starts at the wing tips. A warning of the impending stall is desirable in any case, but is particularly desirable with airplanes of the latter type.
Contributing Partner: UNT Libraries Government Documents Department
Aerodynamic characteristics of a 4-engine monoplane showing effects of enclosing the engines in the wing and comparisons of tractor- and pusher-propeller arrangements

Aerodynamic characteristics of a 4-engine monoplane showing effects of enclosing the engines in the wing and comparisons of tractor- and pusher-propeller arrangements

Date: April 1, 1938
Creator: Wilson, Herbert A , Jr
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Aerodynamic characteristics of a large number of airfoils tested in the variable-density wind tunnel

Aerodynamic characteristics of a large number of airfoils tested in the variable-density wind tunnel

Date: January 1, 1938
Creator: Pinkerton, Robert M & Greenberg, Harry
Description: The aerodynamic characteristics of a large number of miscellaneous airfoils tested in the variable-density tunnel have been reduced to a comparable form and are published in this report for convenient reference. Plots of the standard characteristics are given in tabular form. Included is a tabulation of important characteristics for the related airfoils reported in NACA report 460. This report, in conjunction with NACA report 610, makes available in comparable and convenient form the aerodynamic data for airfoils tested in the variable-density tunnel since January 1, 1931.
Contributing Partner: UNT Libraries Government Documents Department
The aerodynamic characteristics of four full-scale propellers having different plan forms

The aerodynamic characteristics of four full-scale propellers having different plan forms

Date: January 1, 1938
Creator: Hartman, Edwin P & Biermann, David
Description: Tests were made of four propellers, with diameters of 10 feet, having different blade plan forms. One propeller (Navy design no. 5868-r6) was of the usual present-day type and was used as a basis of comparison for the other three, which had unusual plan forms distinguished by the inward (toward the hub) location of the sections having the greatest blade width. It was found that propellers with points of maximum blade width occurring closer to the hub than on the present-day type of blade had higher peak efficiencies but lower take-off efficiencies. This results was found true for a "clean" liquid-cooled engine installation. It appears that some modification could be made to present plan forms which would produce propellers having more satisfactory aerodynamic qualities. The propellers with the inward location of the points of maximum blade width had lower thrust and power coefficients and stalled earlier than the present-day type.
Contributing Partner: UNT Libraries Government Documents Department
The aerodynamic characteristics of full-scale propellers having 2, 3, and 4 blades of Clark y and R.A.F. 6 airfoil sections

The aerodynamic characteristics of full-scale propellers having 2, 3, and 4 blades of Clark y and R.A.F. 6 airfoil sections

Date: January 1, 1938
Creator: Hartman, Edwin P & Biermann, David
Description: Aerodynamic tests were made of seven full-scale 10-foot-diameter propellers of recent design comprising three groups. The first group was composed of three propellers having Clark y airfoil sections and the second group was composed of three propellers having R.A.F. 6 airfoil sections, the propellers of each group having 2, 3, and 4 blades. The third group was composed of two propellers, the 2-blade propeller taken from the second group and another propeller having the same airfoil section and number of blades but with the width and thickness 50 percent greater. The tests of these propellers reveal the effect of changes in solidity resulting either from increasing the number of blades or from increasing the blade width propeller design charts and methods of computing propeller thrust are included.
Contributing Partner: UNT Libraries Government Documents Department
The aerodynamic drag of five models of side floats N.A.C.A. Models 51-E, 51-F, 51-G, 51-H, 51-J

The aerodynamic drag of five models of side floats N.A.C.A. Models 51-E, 51-F, 51-G, 51-H, 51-J

Date: December 1, 1938
Creator: House, R O
Description: The drag of five models of side floats was measured in the N.A.C.A. 7- by 10-foot wind tunnel. The most promising method of reducing the drag of floats indicated by these tests is lowering the angle at which the floats are rigged. The addition of a step to a float does not always increase the drag in the flying range, floats with steps sometimes having lower drag than similar floats without steps. Making the bow chine no higher than necessary might result in a reduction in air drag because of the lower angle of pitch of the chines. Since side floats are used formally to obtain lateral stability when the seaplane is operating on the water at slow speeds or at rest, greater consideration can be given to factors affecting aerodynamic drag than is possible for other types of floats and hulls.
Contributing Partner: UNT Libraries Government Documents Department
Airfoil section characteristics as applied to the prediction of air forces and their distribution on wings

Airfoil section characteristics as applied to the prediction of air forces and their distribution on wings

Date: January 1, 1938
Creator: Jacobs, Eastman N & Rhode, R V
Description: The results of previous reports dealing with airfoil section characteristics and span load distribution data are coordinated into a method for determining the air forces and their distribution on airplane wings. Formulas are given from which the resultant force distribution may be combined to find the wing aerodynamic center and pitching moment. The force distribution may also be resolved to determine the distribution of chord and beam components. The forces are resolved in such a manner that it is unnecessary to take the induced drag into account. An illustration of the method is given for a monoplane and a biplane for the conditions of steady flight and a sharp-edge gust. The force determination is completed by outlining a procedure for finding the distribution of load along the chord of airfoil sections.
Contributing Partner: UNT Libraries Government Documents Department
Application and testing of transparent plastics used in airplane construction

Application and testing of transparent plastics used in airplane construction

Date: November 1, 1938
Creator: Riechers, K & Olms, J
Description: This report concerns the efforts being made to remove the source of danger to passengers arising from the fracturing of silicate glass. Some of the alternatives presented include: single-layer safety glass, multi-layer safety glass, transparent plastic resins. Some of the resins considered are celluloid, cellulose acetates, and mixtures of polymers.
Contributing Partner: UNT Libraries Government Documents Department
Approximate stress analysis of multistringer beams with shear deformation of the flanges

Approximate stress analysis of multistringer beams with shear deformation of the flanges

Date: January 1, 1938
Creator: Kuhn, Paul
Description: The problem of the skin-stringer combinations used as axially loaded panels or as covers for box beams is considered from the point of view of the practical stress analyst. By a simple substitution the problem is reduced to the problem of the single-stringer structure, which has been treated in NACA Report no. 608. The method of making this substitution is essentially empirical; in order to justify it, comparisons are shown between calculations and strain-gage tests of three beams tested by the author and of one compression panel and three beams tested and reported elsewhere.
Contributing Partner: UNT Libraries Government Documents Department
Auto-ignition and combustion of diesel fuel in a constant-volume bomb

Auto-ignition and combustion of diesel fuel in a constant-volume bomb

Date: January 1, 1938
Creator: Selden, Robert F
Description: Report presents the results of a study of variations in ignition lag and combustion associated with changes in air temperature and density for a diesel fuel in a constant-volume bomb. The test results have been discussed in terms of engine performance wherever comparisons could be drawn. The most important conclusions drawn from this investigation are: the ignition lag was essentially independent of the injected fuel quantity. Extrapolation of the curves for the fuel used shows that the lag could not be greatly decreased by exceeding the compression-ignition engines. In order to obtain the best combustion and thermal efficiency, it was desirable to use the longest ignition lag consistent with a permissible rate of pressure rise.
Contributing Partner: UNT Libraries Government Documents Department
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