UNT Libraries Government Documents Department - 110 Matching Results

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The Aerodynamic Drag of Five Models of Side Floats N.A.C.A. Models 51-E, 51-F, 51-G, 51-H, 51-J

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" (p. 1).
Date: December 1938
Creator: House, R. O.
open access

Aerodynamic Effects of a Split Flap on the Spinning Characteristics of a Monoplane Model

Description: From Summary: "The investigation described in this report was made to determine the change in aerodynamic forces and moments produced by split flaps in a steady spin. The test were made with the spinning balance in the NACA 5-foot vertical wind tunnel. A low-wing monoplane model was tested with and without the split flaps in 12 spinning attitudes chosen to cover the probable spinning range. The results obtained indicate that the use of split flaps on an airplane is unlikely, in any case, to hav… more
Date: December 1934
Creator: Bamber, M. J.
open access

Air flow in a separating laminar boundary layer

Description: Report discussing the speed distribution in a laminar boundary layer on the surface of an elliptic cylinder, of major and minor axes 11.78 and 3.98 inches, respectively, has been determined by means of a hot-wire anemometer. The direction of the impinging air stream was parallel to the major axis. Special attention was given to the region of separation and to the exact location of the point of separation. An approximate method, developed by K. Pohlhausen for computing the speed distribution, th… more
Date: December 1, 1934
Creator: Schubauer, G. B.
open access

Aircraft compass characteristics

Description: From Summary: "A description of the test methods used at the National Bureau of Standards for determining the characteristics of aircraft compasses is given. The methods described are particularly applicable to compasses in which mineral oil is used as the damping liquid. Data on the viscosity and density of certain mineral oils used in United States Navy aircraft compasses are presented. Results of flight tests are presented."
Date: December 14, 1935
Creator: Peterson, John B. & Smith, Clyde W.
open access

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

Description: "This report presents a discussion of longitudinal stability in gliding flight together with a series of charts with which the stability characteristics of any airplane may be readily estimated. The relationships governing stability characteristics are derived from equations of equilibrium referred to moving axes that are tangent and perpendicular to the instantaneous flight path. It is shown that instability of the motion can arise only through an increase of linear and angular momentum in the… more
Date: December 13, 1934
Creator: Zimmerman, Charles H.
open access

Automatic Stability of Airplanes

Description: It is endeavored in this report to give a full outline of the problem of airplane stability and to classify the proposed solutions systematically. Longitudinal stability, which can be studied separately, is considered first. The combination of lateral and directional stabilities, which cannot be separated, will be dealt with later.
Date: December 1932
Creator: Haus
open access

Automatic Stabilization

Description: This report lays more stress on the principles underlying automatic piloting than on the means of applications. Mechanical details of servomotors and the mechanical release device necessary to assure instantaneous return of the controls to the pilot in case of malfunction are not included. Descriptions are provided of various commercial systems.
Date: December 1936
Creator: Haus
open access

A balanced diaphragm type of maximum cylinder pressure indicator

Description: A balanced diaphragm type of maximum cylinder pressure indicator was designed to give results consistent with engine operating conditions. The apparatus consists of a pressure element, a source of controlled high pressure and a neon lamp circuit. The pressure element, which is very compact, permits location of the diaphragm within 1/8 inch of the combustion chamber walls without water cooling. The neon lamp circuit used for indicating contact between the diaphragm and support facilitates the us… more
Date: December 1930
Creator: Spanogle, J. A. & Collins, John H., Jr.
open access

The Breda Wind Tunnel

Description: A description of the design and construction of the Breda wind tunnel. The tunnel is equipped with a two-meter throat diameter and a 310 kph velocity potential.
Date: December 1939
Creator: Pittoni, Mario
open access

The Cetene Scale and the Induction Period Preceding the Spontaneous Ignition of Diesel Fuels in Bombs

Description: In the present report a comparison is made between the scale obtained with mixtures of cetane and l-methyl naphthalene in a bomb, and that obtained with the same fuels in a Waukesha engine. The tests were conducted in a metal bomb heated by a Nichrome spiral. The fuel was injected into the bomb from a Bosch jet by means of a specially constructed plunger pump. The instant injection and the pressure curve in the bomb were registered by a beam of light which was reflected from a mirror connected … more
Date: December 1936
Creator: Michailova, M. N. & Neumann, M. B.
open access

The characteristics of 78 related airfoil sections from tests in the variable-density wind tunnel

Description: An investigation of a large group of related airfoils was made in the NACA variable-density wind tunnel at a large value of the Reynolds number. The tests were made to provide data that may be directly employed for a rational choice of the most suitable airfoil section for a given application. The variation of the aerodynamic characteristics with variations in thickness and mean-line form were systematically studied. (author).
Date: December 20, 1932
Creator: Jacobs, Eastman N.; Ward, Kenneth E. & Pinkerton, Robert M.
open access

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

Description: From Summary: "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 alo… more
Date: December 1933
Creator: Anderson, Raymond F.
open access

Coal-Mine Fatalities in November, 1930

Description: Report issued by the U.S. Bureau of Mines on the fatalities of coal miners in November, 1930. The common causes of death, and the location of the mines that the fatalities occurred in are listed. This report includes tables.
Date: December 1931
Creator: Adams, William Waugh & Chenoweth, L.
open access

Comparison of free-spinning wind-tunnel results with corresponding full-scale spin results

Description: Report presenting a study of comparable information on full-scale spinning results and NACA free-spinning wind-tunnel results in order to determine the degree of reliability of tunnel results in predicting the spinning behavior of airplanes. Satisfactory agreement between model and airplane was found in 16 instances and disagreement was found in 5 instances.
Date: December 1938
Creator: Seidman, Oscar & Neihouse, A. I.
open access

A comparison of fuel sprays from several types of injection nozzles

Description: This report presents the tests results of a series of tests made of the sprays from 14 fuel injection nozzles of 9 different types, the sprays being injected into air at atmospheric density and at 6 and 14 times atmospheric density. High-speed spark photographs of the sprays from each nozzle at each air density were taken at the rate of 2,000 per second, and from them were obtained the dimensions of the sprays and the rates of spray-tip penetration. The sprays were also injected against plastic… more
Date: December 4, 1934
Creator: Lee, Dana W.
open access

A complete tank test of the hull of the Sikorsky S-40 flying boat - American Clipper Class

Description: The results of a complete test in the N.A.C.A. tank on a model of the hull of Sikorsky S-40 flying boat ('American Clipper') are reported. The test data are given in tables and curves. From these data non-dimensional coefficients are derived for use in take-off calculations and the take-off time and run for the S-40 are computed. The computed take-off time was obtained by the Sikorsky Aviation Corporation in performance tests of the actual craft.
Date: December 1934
Creator: Dawson, John R.
open access

Contribution to the Aerodynamics of Rotating-Wing Aircraft

Description: "The chief defect of the investigations up to now was the assumption of a more or less arbitrary "mean" drag coefficient for a section of the blade. This defect is remedied through replacement of the constant coefficient by a function of higher order which corresponds to the polar curve of the employed profile. In that way it is possible to extend the theory to include the entire range from "autogyro" without power input to the driven "helicopter" with forward-tilted rotor axis. The treatment i… more
Date: December 1939
Creator: Sissingh, G.
open access

Cooling characteristics of a 2-row radial engine

Description: This report presents the results of cooling tests conducted on a calibrated GR-1535 Pratt and Whitney Wasp, Jr. Engine installed in a Vought X04U-2 airplane. The tests were made in the NACA full-scale tunnel at air speeds from 70 to 120 miles per hour, at engine speeds from 1,500 to 2,600 r.p.m., and at manifold pressures from 19 to 33 inches of mercury absolute. A Smith controllable propeller was used to facilitate obtaining the different combinations of engine speed, power, and manifold press… more
Date: December 4, 1934
Creator: Schey, Oscar W. & Rollin, Vern G.
open access

Development of a Non-Autorotative Airplane Capable of Steep Landing

Description: In the following we develop a non-autorotating monoplane wing. The conditions imposed on such a wing, aside from its freedom from autorotation,with respect to its polars and its construction, are taken into account as far as possible. It is indicated that the autorotation characteristics of a wing are dependent upon the speed of air flow as well as on the angle of yaw. This report postulates the knowledge of the behavior of certain conventional wings of different chords and cambers with respect… more
Date: December 1931
Creator: Schmidt, Wilhelm
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