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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

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

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

Full-scale wind-tunnel tests of a PCA-2 autogiro rotor

Description: This report presents the results of force tests on and air-flow surveys near PCA-2 autogiro rotor in the NACA full-scale wind tunnel. The force tests were made at three pitch settings and several rotor speeds; the effect of fairing protuberances on the rotor blade was determined. Induced downwash and yaw angles were determined at low tip-speed ratios in a plane 1 1/2 feet above the path of the blade tips. The results show that the maximum l/d of the rotor cannot be appreciably increased by incr… more
Date: October 12, 1934
Creator: Wheatley, John B. & Hood, Manley J.
open access

Experimental investigation of the Robinson-type cup anemometer

Description: This report presents the results of wind tunnel tests on a Robinson-type anemometer. The investigation covered force measurements on individual cups, as well as static and dynamic torque measurements and calibrations on complete cup wheels. In the tests on individual cups 5 cup forms were used and in the measurements on complete cup wheels 4 cup wheels with 3 arm lengths for each cup wheel were tested. All the results are presented in graphical form.
Date: October 10, 1934
Creator: Brevoort, M. J. & Joyner, U. T.
open access

The Measurement of the Field of View From Airplane Cockpits

Description: "A method has been devised for the angular measurement and graphic portrayal of the view obtained from the pilot's cockpit of an airplane. The assumption upon which the method is based and a description of the instrument, designated a "visiometer", used in the measurement are given. Account is taken of the fact that the pilot has two eyes and two separate sources of vision. The view is represented on charts using an equal-area polar projection, a description and proof of which are given" (p. 16… more
Date: October 3, 1934
Creator: Gough, Melvin N.
open access

The effect of baffles on the temperature distribution and heat-transfer coefficients of finned cylinders

Description: This report presents the results of an investigation to determine the effect of baffles on the temperature distribution and the heat-transfer coefficient of finned cylinders. The tests were conducted in a 30-inch wind tunnel on electrically heated cylinders with fins of 0.25 and 0.31 inch pitch. The results of these tests showed that the use of integral baffles gave a reduction of 31.9 percent in the rear wall temperatures and an increase of 54.2 percent in the heat transfer coefficient as comp… more
Date: September 26, 1934
Creator: Schey, Oscar W. & Rollin, Vern G.
open access

Some Factors Affecting Combustion in an Internal-Combustion Engine

Description: "An investigation of the combustion of gasoline, safety, and diesel fuels was made in the NACA combustion apparatus under conditions of temperature that permitted ignition by spark with direct fuel injection, in spite of the compression ratio of 12.7 employed. The influence of such variables as injection advance angle, jacket temperature, engine speed, and spark position was studied. The most pronounced effect was that an increase in the injection advance angle (beyond a certain minimum value) … more
Date: September 11, 1934
Creator: Rothrock, A. M. & Cohn, Mildred
open access

General equations for the stress analysis of rings

Description: In this report it is shown that the shear, axial force, and moment at one point in a simple ring subjected to any loading condition can be given by three independent equations involving certain integrals that must be evaluated regardless of the method of analysis used. It is also shown how symmetry of the ring alone or of the ring and the loading about 1 or 2 axes makes it possible to simplify the three equations and greatly reduces the number of integrals that must be evaluated. Application of… more
Date: August 10, 1934
Creator: Lundquist, Eugene E. & Burke, Walter F.
open access

Wind-tunnel research comparing lateral control devices particularly at high angles of attack 13: auxiliary airfoils used as external ailerons

Description: This is the thirteenth report on a series of systematic tests comparing lateral control devices with particular reference to their effectiveness at high angles of attack. The present wind tunnel tests were made to determine the most feasible locations for lateral control surfaces mounted externally to a rectangular Clark y wing.
Date: July 23, 1934
Creator: Weick, Fred E. & Noyes, Richard W.
open access

The drag of airplane wheels, wheel fairings, and landing gears 2: nonretractable and partly retractable landing gears

Description: This is the second report giving the results obtained in the NACA 20-foot wind tunnel on the drag due to landing gears. The present report gives the results of tests of nonretractable and partly retractable landing gears intended for heavier low-wing monoplanes of the transport and bomber type.
Date: June 21, 1934
Creator: Biermann, David & Herrnstein, William H., Jr.
open access

The Effect of Spray Strips on the Take-Off Performance of a Model of a Flying-Boat Hull

Description: "The effect on the take-off performance of a model of the hull of a typical flying boat, Navy PH-1, of fitting spray strips of four different widths, each at three different angles, was determined by model tests in the NACA Tank. Spray strips of widths up to 3 percent of the beam improve the general performance at speeds near the hump and reduce the spray thrown. A downward angle of 30 degrees to 45 degrees in the neighborhood of the step seems most favorable for the reduction of the spray" (p.… more
Date: June 15, 1934
Creator: Truscott, Starr
open access

Scale Effect on Clark Y Airfoil Characteristics From NACA Full-Scale Wind-Tunnel Tests

Description: This report presents the results of wind tunnel tests conducted to determine the aerodynamic characteristics of the Clark Y airfoil over a large range of Reynolds numbers. Three airfoils of aspect ratio 6 and with 4, 6, and 8 foot chords were tested at velocities between 25 and 118 miles per hour, and the characteristics were obtained for Reynolds numbers (based on the airfoil chord) in the range between 1,000,000 and 9,000,000 at the low angles of attack, and between 1,000,000 and 6,000,000 at… more
Date: June 14, 1934
Creator: Silverstein, Abe
open access

The influence of tip shape on the wing load distribution as determined by flight tests

Description: "Pressure measurements were made in flight on the right upper wing of an M-3 airplane. The effects of tip plan form, washout, and transverse camber were investigated with eight tip forms in unyawed conditions through the range of positive lift coefficients from zero lift to the stall. The conclusion is that the tip plan form does not influence the span distribution of the coefficients of normal force and moment. It is shown inferentially that temperature, humidity, and the aging of the wood and… more
Date: June 9, 1934
Creator: Rhode, Richard V.
open access

Wind-Tunnel Research Comparing Lateral Control Devices, Particularly at High Angles of Attack 12: Upper-Surface Ailerons on Wings With Split Flaps

Description: "This report covers the twelfth of a series of tests conducted to compare different lateral control devices with particular reference to their effectiveness at high angles of attack. The present wind tunnel tests were made with two sizes of upper-surface ailerons on rectangular Clark Y wing models equipped with full span split flaps. The tests showed the effect of the upper-surface ailerons and of the split flaps on the general performance characteristics of the wings, and on the lateral contro… more
Date: June 8, 1934
Creator: Weick, Fred E. & Wenzinger, Carl J.
open access

Tests of nacelle-propeller combinations in various positions with reference to wings 6: wings and nacelles with pusher propeller

Description: This report is the sixth of a series giving wind tunnel tests results on the interference drag and propulsive efficiency of nacelle-propeller-wing combinations. The present report gives the results of tests of a radial-engine nacelle with pusher propeller in 17 positions with reference to a Clark Y wing; tests of the same nacelle and propeller in three positions with reference to a thick wing; and tests of a body and pusher propeller with the thick wing, simulating the case of a propeller drive… more
Date: June 7, 1934
Creator: Wood, Donald H. & Bioletti, Carlton
open access

On the Theory of Laminar Boundary Layers Involving Separation

Description: "This paper presents a mathematical discussion of the laminar boundary layer, which was developed with a view of facilitating the investigation of those boundary layers in particular for which the phenomenon of separation occurs. The treatment starts with a slight modification of the form of the boundary layer equation first published by Von Mises. Two approximate solutions of this equation are found, one of which is exact at the outer edge of the boundary layer while the other is exact at the … more
Date: May 22, 1934
Creator: von Karman, T. & Millikan, C. B.
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