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Gliding in Convection Currents

Description: "A survey of the possibilities of gliding in convection currents reveals that heretofore only the most simple kind of ascending convection currents, that is, the "thermic" of insolation, has been utilized to any extent. With the increasing experience in gliding, the utilization of the peculiar nature of the "wind thermic" and increased glider speed promises further advances. Evening, ocean, and height "thermic" are still in the exploration stage, and therefore not amenable to survey in their ef… more
Date: January 1935
Creator: Georgii, W.
Partner: UNT Libraries Government Documents Department
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The Effect of Lateral Inclination of the Thrust Axis and of Sweepback of the Leading Edge of the Wing on Propulsive and Net Efficiencies of a Wing-Nacelle-Propeller Combination

Description: "This report describes and gives the results of tests made to determine the effect of lateral inclination of the propeller thrust axis to the direction of flight. A wing-nacelle-propeller combination with the nacelle axis located successively parallel to and at 15 degrees to the perpendicular to the leading edge of a wing was tested with the combination at several angles of yaw. Tests of the wing alone at the same angles of yaw were also made" (p. 1).
Date: April 1935
Creator: Wood, Donald H. & Windler, Ray
Partner: UNT Libraries Government Documents Department
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The Relative Hydrodynamic Resistance of Various Types of Rivet Heads from Tests of Planning Surfaces, Special Report

Description: The Committee was requested to investigate the effect of various types of rivet heads on hydrodynamic resistance. The proposal was made to obtain the resistance of the various types of rivets by tests of planing surfaces on which the full size rivets would be arranged. The testing methods, results and conclusions are given.
Date: July 1935
Creator: Truscott, Starr & Parkinson, John B.
Partner: UNT Libraries Government Documents Department
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Ice Prevention on Aircraft by Means of Impregnated Leather Covers, Special Report

Description: "The National Advisory Committee for Aeronautics is testing the effectiveness of a method to prevent the formation of ice on airplanes. The system makes use of a leather cover that is attached to the leading edge of the wing. A small tube, attached to the inner surface of the leather, distributes to the leading edge a solution that permeates throughout the leather and inhibits the formation of ice on the surface. About 25 pounds of the liquid per hour would be sufficient to prevent ice from for… more
Date: August 1935
Creator: Clay, William C.
Partner: UNT Libraries Government Documents Department
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Kay 331 Gyroplane (British): All-Metal Single-Seat Light Rotor Plane

Description: Circular presenting a description of the Kay 331 gyroplane, which is an all-metal single-seater with a Pobjoy R engine. A description of the propeller, control, fuselage, tail, flight characteristics, specifications, drawings, and photographs are provided.
Date: January 1935
Partner: UNT Libraries Government Documents Department
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Tests of a Wing-Nacelle-Propeller Combination at Several Pitch Settings Up to 42 Degrees

Description: This report presents the results of tests of a 4-foot model of Navy propeller No. 4412 in conjunction with an NACA cowled nacelle mounted ahead of a thick wing in the 20-foot propeller-research tunnel. A range of propeller pitches from 17 degrees to 42 degrees at 0.75r was covered, and for this propeller the efficiency reached a maximum at a pitch setting of 27 degrees; at high pitches the efficiencies were slightly lower. The corrected propulsive efficiency is shown to be independent of the an… more
Date: November 12, 1935
Creator: Windler, Ray
Partner: UNT Libraries Government Documents Department
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Potential flow about arbitrary biplane wing sections

Description: From Summary: "A rigorous treatment is given of the problem of determining the two-dimensional potential flow around arbitrary biplane cellules. The analysis involves the use of elliptic functions and is sufficiently general to include the effects of such elements as the section shapes, the chord ratio, gap, stagger, and decalage, which elements may be specified arbitrarily. The flow problem is resolved by making use of the methods of conformal representation. Thus the solution of the problem o… more
Date: June 8, 1935
Creator: Garrick, I. E.
Partner: UNT Libraries Government Documents Department
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Tank tests of NACA model 40 series of hulls for small flying boats and amphibians

Description: From Summary: "The NACA model 40 series of flying-boat hull models consists of 2 forebodies and 3 afterbodies combined to provide several forms suitable for use in small marine aircraft. One forebody is the usual form with hollow bow sections and the other has a bottom surface that is completely developable from bow to step. The afterbodies include a short pointed afterbody with an extension for the tail surfaces, a long afterbody similar to that of a seaplane float but long enough to carry the… more
Date: June 19, 1935
Creator: Parkinson, John B. & Dawson, John R.
Partner: UNT Libraries Government Documents Department
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Combustion in a Bomb With a Fuel-Injection System

Description: "Fuel injected into a spherical bomb filled with air at a desired density and temperature could be ignited with a spark a few thousandths of a second after injection, an interval comparable with the ignition lag in fuel-injection engines. The effect of several variables on the extent and rate of combustion was investigated: time intervals between injection and ignition of fuel of 0.003 to 0.06 second and one of 5 minutes; initial air temperatures of 100 degrees C. to 250 degrees C.; initial air… more
Date: August 9, 1935
Creator: Cohn, Mildred & Spencer, Robert C.
Partner: UNT Libraries Government Documents Department
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Effects of air-fuel spray and flame formation in a compression-ignition engine

Description: "High-speed motion pictures were taken at the rate of 2,500 frames per second of the fuel spray and flame formation in the combustion chamber of the NACA combustion apparatus. The compression ratio was 13.2 and the speed 1,500 revolutions per minute. An optical indicator was used to record the time-pressure relationship in the combustion chamber. The air-fuel ratio was varied from 10.4 to 365. The results showed that as the air-fuel ratio was increased definite stratification of the charge occu… more
Date: August 26, 1935
Creator: Rothrock, A. M. & Waldron, C. D.
Partner: UNT Libraries Government Documents Department
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The effect of turbulence on the drag of flat plates

Description: "In determining the effect of turbulence on the forces exerted on bodies in the air stream of a wind tunnel, it is commonly assumed that the indications of the standard Pitot-static tube used to determine the air speed are not dependent on the turbulence. To investigate the truth of this assumption, the drag of a normally exposed flat plate, the difference in pressure between the front and rear of a thin circular disk, the rate of rotation of a vane anemometer, and the pressure developed by a s… more
Date: June 22, 1935
Creator: Schubauer, G. B. & Dryden, H. L.
Partner: UNT Libraries Government Documents Department
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Wind-Tunnel Interference With Particular Reference to Off-Center Positions of the Wing and to the Downwash at the Tail

Description: "The theory of wind tunnel boundary influence on the downwash from a wing has been extended to provide more complete corrections for application to airplane test data. The first section of the report gives the corrections of the lifting line for wing positions above or below the tunnel center line; the second section shows the manner in which the induced boundary influence changes with distance aft of the lifting line. Values of the boundary corrections are given for off-center positions of the… more
Date: June 28, 1935
Creator: Silverstein, Abe & White, James A.
Partner: UNT Libraries Government Documents Department
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Effect of Tip Shape and Dihedral on Lateral-Stability Characteristics

Description: This report presents the results of wind tunnel tests to determine the effect of wing-tip shape and dihedral on some of the aerodynamic characteristics of Clark Y wings that affect the performance and lateral stability of airplanes. Force tests at several angles of yaw and rotation tests at zero yaw were made. From these tests the rates of change of rolling moment, yawing moment, and cross-wind force coefficients with angle of yaw and the rate of change of rolling moment coefficient with rollin… more
Date: August 27, 1935
Creator: Shortal, Joseph A.
Partner: UNT Libraries Government Documents Department
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Wind-Tunnel Investigation of the Aerodynamic Balancing of Upper-Surface Ailerons and Split Flaps

Description: This report presents the results of wind tunnel tests to determine the effectiveness of various methods of reducing the high control forces of unbalanced upper-surface ailerons and of unbalanced split flaps. A balanced split flap was developed that required control forces about half those of the unbalanced split flap when the balanced split flap was deflected to give approximately the same maximum lift.
Date: August 20, 1935
Creator: Wenzinger, Carl J.
Partner: UNT Libraries Government Documents Department
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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.
Partner: UNT Libraries Government Documents Department
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Some Effects of Argon and Helium Upon Explosions of Carbon Monoxide and Oxygen

Description: Report presents the results of an investigation conducted to study the effects of the inert gases, argon and helium, upon flame speed and expansion ratio in exploding mixtures of carbon monoxide, oxygen and water. For the particular gas mixtures investigated the results show that: (1) With the possible exception of helium in small amounts the addition of inert gas always produces decreased flame speed and expansion ratio; (2) like volumes of argon and helium have very different effects upon fla… more
Date: September 25, 1935
Creator: Fiock, Ernst F. & Roeder, Carl H.
Partner: UNT Libraries Government Documents Department
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Wind-Tunnel Investigation of Ordinary and Split Flaps on Airfoils of Different Profile

Description: Report presents the results of wind tunnel tests of the Clark Y, the NACA 23012 and the NACA 23021 airfoils equipped with full-span ordinary flaps and with full-span simple split flaps. The principal object of the tests was to determine the characteristics of the airfoils with ordinary flaps and in addition, to determine the relative merits of the various airfoils when equipped with either ordinary flaps or with simple split flaps. The Clark Y airfoil was tested with 3 widths of ordinary flap, … more
Date: October 25, 1935
Creator: Wenzinger, Carl J.
Partner: UNT Libraries Government Documents Department
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Air flow around finned cylinders

Description: Report presents the results of a study made to determine the air-flow characteristics around finned cylinders. Air-flow distribution is given for a smooth cylinder, for a finned cylinder having several fin spacings and fin widths, and for a cylinder with several types of baffle with various entrance and exit shapes. The results of these tests show: that flow characteristics around a cylinder are not so critical to changes in fin width as they are to fin spacing; that the entrance of the baffle … more
Date: November 7, 1935
Creator: Brevoort, M. J. & Rollin, Vern G.
Partner: UNT Libraries Government Documents Department
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Further Studies of Flame Movement and Pressure Development in an Engine Cylinder

Description: This report describes an investigation using a stroboscopic apparatus for observing flame movement through a large number of small windows distributed over the head of a spark-ignition engine in following flame spread with combustion chambers of different shapes at two engine speed and for a variety of spark-plug locations including single and twin ignition. The principal factors influencing flame movement in the engine are discussed, and the lack of reliable information regarding their separat… more
Date: September 1935
Creator: Marvin, Charles F., Jr.; Wharton, Armistead & Roeder, Carl H.
Partner: UNT Libraries Government Documents Department
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Preliminary tests in the NACA free-spinning wind tunnel

Description: Typical models and the testing technique used in the NACA free-spinning wind tunnel are described in detail. The results of tests on two models afford a comparison between the spinning characteristics of scale models in the tunnel and of the airplanes that they represent.
Date: October 29, 1935
Creator: Zimmerman, C. H.
Partner: UNT Libraries Government Documents Department
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A Turbulence Indicator Utilizing the Diffusion of Heat

Description: This report describes a method of determining the turbulence in wind tunnels. The effect of turbulence upon the diffusion of heat from a small electrically heated wire in an air stream was investigated. The turbulence of the stream was introduced by a series of geometrically similar screens placed one at a time across the upstream section of the tunnel. With the wire set at various distances from the screens, curves of temperature distribution were obtained by traversing the heated wake at a di… more
Date: March 8, 1935
Creator: Schubauer, G. B.
Partner: UNT Libraries Government Documents Department
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Some effects of injection advance angle, engine-jacket temperature, and speed on combustion in a compression-ignition engine

Description: "An optical indicator and a high-speed motion-picture camera capable of operating at the rate of 2,000 frames per second were used to record simultaneously the pressure development and the flame formation in the combustion chamber of the NACA combustion apparatus. Tests were made at engine speeds of 570 and 1,500 r.p.m. The engine-jacket temperature was varied from 100 degrees to 300 degrees F. And the injection advance angle from 13 degrees after top center to 120 degrees before top center. Th… more
Date: January 15, 1935
Creator: Rothrock, A. M. & Waldron, C. D.
Partner: UNT Libraries Government Documents Department
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Noise From Two-Blade Propellers

Description: "The two-blade propeller, one of the most powerful sources of sound known, has been studied with the view of obtaining fundamental information concerning the noise emission. In order to eliminate engine noise, the propeller was mounted on an electric motor. A microphone was used to pick up the sound whose characteristics were studied electrically. The distribution of noise throughout the frequency range, as well as the spatial distribution about the propeller, was studied. The results are given… more
Date: January 17, 1935
Creator: Stowell, E. Z. & Deming, A. F.
Partner: UNT Libraries Government Documents Department
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