UNT Libraries Government Documents Department - 171 Matching Results

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open access

The influence of wing setting on the wing load and rotor speed of a PCA-2 autogiro as determined in flight

Description: Flight tests were made on PCA-2 autogiro with wing settings of 2.2 degrees, 0.9 degrees, and -0.5 degrees. The wing load and rotor speed were measured in steady glides. The results obtained show that a wide variation in rotor speed as a function of air speed can be obtained by a suitable adjustment of the wing setting; that by decreasing the wing setting the upper safe flying speed, determined by the decrease is rotor speed, is greatly increased; and that the interference of the wing on the rot… more
Date: December 28, 1934
Creator: Wheatley, John B.
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

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

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

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

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

Effect of Combustion-Chamber Shape on the Performance of a Prechamber Compression-Ignition Engine

Description: "The effect on engine performance of variations in the shape of the prechamber, the shape and direction of the connecting passage, the chamber volume using a tangential passage, the injection system, and the direction of the fuel spray in the chamber was investigated using a 5 by 7 inch single-cylinder compression-ignition engine. The results show that the performance of this engine can be considerably improved by selecting the best combination of variables and incorporating them in a single de… more
Date: December 1934
Creator: Moore, C. S. & Collins, J. H., Jr.
open access

The Effect of Weight and Drag on the Sinking Speed and Lift/Drag Ratio of Gliders

Description: The most important factors in evaluating performance of gliders are minimum sinking speed and minimum gliding angle. To assure their optimum value the energy necessary for flight, that is, the energy of lift and friction must be kept very low, or in other words, weight and total drag which have a decisive effect on the sinking speed and on the gliding angle, must be kept to a minimum. How great the effect of a reduction of these two quantities will be shown in the following.
Date: December 1934
Creator: Kosin, R.
open access

Tabulated Analyses of Texas Crude Oils

Description: Report issued by the U.S. Bureau of Mines covering the crude oils from different regions of Texas. Analysis of the properties of each oil sample from the different regions of the state are presented. This report includes tables, and a map.
Date: December 1934
Creator: Wade, Gustav
open access

The Wave Suppressors Used in the N.A.C.A. Tank

Description: "So long a time was required for the disturbed water to become quiet after a model had been towed down the N.A.C.A. tank, that only 12 to 18 runs a day could be made. In order to shorten the time lost in waiting between runs, several different methods of suppressing the waves were tried. The most effective form of wave suppressor developed consists of wooden frames covered with fine copper screening and secured horizontally just beneath the surface of the water at the sides of the tank" (p. 1).
Date: December 1934
Creator: Truscott, Starr
open access

The drag of airplane wheels, wheel fairings, and landing gears - 3

Description: The tests reported in this report conclude the investigation of landing-gear drag that has been carried out in the NACA 20-foot wind tunnel. They supplement earlier tests (reported in Technical Report No. 485) made with full-scale dummy wheels, wheel fairings, and landing gears intended for airplanes of 3,000 pounds gross weight and include tests of tail wheels and tail skids.
Date: November 21, 1934
Creator: Herrnstein, William H., Jr. & Biermann, David
open access

Spinning characteristics of wings 1: rectangular Clark Y monoplane wing

Description: "A series of wind tunnel tests of a rectangular Clark Y wing was made with the NACA spinning balance as part of a general program of research on airplane spinning. All six components of the aerodynamic force and moment were measured throughout the range of angles of attack, angles of sideslip, and values omega b/2v likely to be attained by a spinning airplane; the results were reduced to coefficient form. It is concluded that a conventional monoplane with a rectangular Clark y wing can be made … more
Date: November 21, 1934
Creator: Bamber, M. J. & Zimmerman, C. H.
open access

Potential Flow About Elongated Bodies of Revolution

Description: "This report presents a method of solving the problem of axial and transverse potential flows around arbitrary elongated bodies of revolution. The solutions of Laplace's equation for the velocity potentials of the axial and transverse flows, the system of coordinates being an elliptic one in a meridian plane, are given. The theory is applied to a body of revolution obtained from a symmetrical Joukowsky profile, a shape resembling an airship hull" (p. 189).
Date: November 12, 1934
Creator: Kaplan, Carl
open access

Flight Investigation of Lateral Control Devices for Use With Full-Span Flaps

Description: This report presents the results of flight tests made on five different lateral control devices that appeared adaptable to wings fitted with full span flaps: controllable auxiliary airfoils (airfoils mounted above and forward of the leading edge of the wings), external ailerons (airfoils mounted above the wing and slightly forward of its maximum ordinate), upper-surface ailerons (similar to split trailing-edge flaps except that they constitute the upper surface of the wing), ailerons that retra… more
Date: November 7, 1934
Creator: Soulé, H. A. & McAvoy, W. H.
open access

The Calculated Effect of Trailing-Edge Flaps on the Take-Off of Flying Boats

Description: "The results of take-off calculations are given for an application of simple trailing-edge flaps to two hypothetical flying boats, one having medium wing and power loading and consequently considerable excess of thrust over total resistance during the take-off run, the other having high wing and power loading and a very low excess thrust. For these seaplanes the effect of downward flap settings was: (1) to increase the total resistance below the stalling speed, (2) to decrease the get-away spee… more
Date: November 1934
Creator: Parkinson, J. B. & Bell, J. W.
open access

Landing characteristics of an autogiro

Description: An investigation to determine the rate of descent, the horizontal velocity, and the attitude at contact of an autogiro in landings was made by the National Advisory Committee for Aeronautics at the request of the Bureau of Air Commerce, Department of Commerce. The investigation covered various types of landings. The results of the investigation disclosed that the maximum rate of descent at contact with the ground (10.6 feet per second) was less than the minimum rate of descent attainable in a s… more
Date: November 1934
Creator: Peck, William C.
open access

The Processes in Spring-Loaded Injection Valves of Solid Injection Oil Engines

Description: "On the premise of a rectangular velocity wave arriving at the valve, the equation of motion of a spring-loaded valve stem is developed and analyzed. It is found that the stem oscillates, the oscillation frequency being consistently above the natural frequency of the nozzle stem alone, and whose amplitudes would increase in the absence of damping. The results are evaluated and verified on an example" (p. 1).
Date: November 1934
Creator: Lutz, O.
open access

A study of the pitching moments and the stability characteristics of monoplanes

Description: "This note presents a study of the pitching moments and the stability characteristics of monoplanes. Expressions for the pitching-moment coefficient and the Diehl stability coefficient for the monoplane are developed, suitable for the use of airplane designers. The effective difference between the high-wing and low-wing types is portrayed and discussed. Comparisons between experimental and computed values are made. Charts for use in the solution of numerical values of the pitching-moment and st… more
Date: November 1934
Creator: Higgins, George J.
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