You limited your search to:

  Partner: UNT Libraries Government Documents Department
 Decade: 1930-1939
 Serial/Series Title: NACA Technical Notes
 Collection: Technical Report Archive and Image Library
Characteristics of an airfoil as affected by fabric sag

Characteristics of an airfoil as affected by fabric sag

Date: August 1, 1932
Creator: Ward, Kenneth E
Description: This report presents the results of tests made at a high value of the Reynolds Number in the N.A.C.A. variable-density wind tunnel to determine the aerodynamic characteristics of an airfoil as affected by fabric sag. Tests were made of two Gottingen 387 airfoils, one having the usual smooth surface and the other having a surface modified to simulate two types of fabric sag. The results of these tests indicate that the usual sagging of the wind covering between ribs has a very small effect on the aerodynamic characteristics of an airfoil.
Contributing Partner: UNT Libraries Government Documents Department
Characteristics of two sharp-nosed airfoils having reduced spinning tendencies

Characteristics of two sharp-nosed airfoils having reduced spinning tendencies

Date: April 1, 1932
Creator: Jacobs, Eastman N
Description: According to Mr. L.D. Bell, of the Consolidated Aircraft Corporation, certain undesirable spinning characteristics of a commercial airplane were eliminated by the addition of a filler to the forward part of the wing to give it a sharp leading edge. To ascertain what aerodynamic effects result from such a change of section, two airfoils having sharp leading edges were tested in the variable-density wind tunnel. Both sections were derived by modifying the Gott. 398. The tests, which were made at a large value of the Reynolds Number, were carried to very large angles of attack to provide data for application to flight at angles of attack well beyond the stall. The characteristics of the sharp-nosed airfoils are compared with those of the normal Gott. 398 airfoil. Both of the sharp-nosed airfoils, which differ in the angle between the upper and lower surfaces at the leading edge, have about the same characteristics. As compared with the normal airfoil, the maximum lift is reduced by approximately 26 per cent, but the objectionable rapidly decreasing lift with angle of attack beyond the stall is eliminated; the profile drag of the section is slightly reduced in the range of the lift coefficient between 0.2 ...
Contributing Partner: UNT Libraries Government Documents Department
The charging process in a high-speed, single-cylinder, four-stroke engine

The charging process in a high-speed, single-cylinder, four-stroke engine

Date: February 1, 1939
Creator: Reynolds, Blake
Description: Experimental measurements and theoretical calculations were made on an aircraft-type, single cylinder engine, in order to determine the physical nature of the inlet process, especially at high piston speeds. The engine was run at speeds from 1,500 to 2,600 r.p.m. (mean piston speeds of 1,370 to 2,380 feet per minute). Measurements were made of the cylinder pressure during the inlet stroke and of the power output and volumetric efficiency. Measurements were also made, with the engine not running, to determine the resistance and mass of air in the inlet valve port at various crank angles. Results of analysis indicate that mass has an appreciable effect, but friction plays the major part in restricting flow. The observed fact that the volumetric efficiency is considerably less than 100 percent is attributed to thermal effects. An estimate was made of the magnitude of these effects in the present case, and their general nature is discussed.
Contributing Partner: UNT Libraries Government Documents Department
Charts expressing the time, velocity, and altitude relations for an airplane diving in a standard atmosphere

Charts expressing the time, velocity, and altitude relations for an airplane diving in a standard atmosphere

Date: April 1, 1937
Creator: Pearson, H A
Description: In this report charts are given showing the relation between time, velocities, and altitude for airplanes having various terminal velocities diving in a standard atmosphere. The range of starting altitudes is from 8,000 to 32,000 feet, and the terminal velocities vary from 150 to 550 miles per hour. A comparison is made between an experimental case and the results obtained from the charts. Examples pointing out the use of the charts are included.
Contributing Partner: UNT Libraries Government Documents Department
Charts for calculating the performance of airplanes having constant-speed propellers

Charts for calculating the performance of airplanes having constant-speed propellers

Date: September 1, 1936
Creator: White, Roland J
Description: Charts are presented for determining the performance of airplanes having variable-pitch propellers, the pitch of which is assumed to be adjusted to maintain constant speed for all rates of flight. The charts are based on the general performance equations developed by Oswald in reference 1, and are used in a similar manner. Examples applying the charts to airplanes having both supercharged and unsupercharged engines are included.
Contributing Partner: UNT Libraries Government Documents Department
Charts for determining the pitching moment of tapered wings with sweepback and twist

Charts for determining the pitching moment of tapered wings with sweepback and twist

Date: December 1, 1933
Creator: Anderson, Raymond F
Description: This report presents a convenient method for calculating the pitching-moment characteristics of tapered wings with sweepback and twist. The method is based on the fact that the pitching-moment characteristics of a wing may be specified by giving the value of the pitching moment at zero lift and the location of the axis about which the axis is constant. Data for calculating these characteristics are presented by curves which apply to wings having a linear distribution of twist along the span and which cover a large range of aspect ratios. The curves are given for wings having straight taper and distorted elliptical plan forms. The characteristics of wings of other shapes may be determined by interpolation.
Contributing Partner: UNT Libraries Government Documents Department
Circular motion of bodies of revolution

Circular motion of bodies of revolution

Date: February 1, 1936
Creator: Kaplan, Carl
Description: The circular motion for airship-like bodies has thus far been calculated only for a prolate ellipsoid of revolution (reference 1, p.133 and reference 2). In this paper, however, the circular motion of elongated bodies of revolution more nearly resembling airships will be investigated. The results will give the effect of rotation on the pressure distribution and thus yield some information as to the stresses set up in an airship in circular flight.
Contributing Partner: UNT Libraries Government Documents Department
Circulation measurements about the tip of an airfoil during flight through a gust

Circulation measurements about the tip of an airfoil during flight through a gust

Date: February 1, 1939
Creator: Kuethe, Arnold
Description: Measurements were made of the circulation about the rectangular tip of a short-span airfoil passing through an artificial gust of known velocity gradient. A Clark Y airfoil of 30-centimeter chord was mounted on a whirling arm and moved at a velocity of 29 meters per second over a vertical gust with a velocity of nearly 7 meters per second. Flow angles were measured with a hot-wire apparatus. The rate at which the lift at the tips of a wing entering a gust is realized was found to be in satisfactory agreement with that predicted on the basis of the two-dimensional theory of von Karman and Sears.
Contributing Partner: UNT Libraries Government Documents Department
Combined beam-column stresses of aluminum-alloy channel sections

Combined beam-column stresses of aluminum-alloy channel sections

Date: September 1, 1939
Creator: Gottlieb, R
Description: The results of a research program to obtain design data on the strength of open-channel aluminum-alloy sections subjected to combined column and beam action. The results of the tests of about 70 specimens were graphed for stresses due to axial load and stresses due to bending loading as functions of length to radius of gyration of the specimens. From these graphs a design chart was derived that is suitable for ready use.
Contributing Partner: UNT Libraries Government Documents Department
Combustion-engine temperatures by the sodium line-reversal method

Combustion-engine temperatures by the sodium line-reversal method

Date: March 1, 1936
Creator: Brevoort, Maurice J
Description: The sodium line-reversal method has been used in some preliminary measurements of flame temperature. Improvements in the method involving a photographic recorder and a means of correcting for the dirtiness of the windows are described. The temperatures so obtained are compared with those calculated from pressure diagrams.
Contributing Partner: UNT Libraries Government Documents Department