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The Transition Phase in the Take-Off of an Airplane

Description: Report presents the results of an investigation to determine the character and importance of the transition phase between the ground run and steady climb in the take-off of an airplane and the effects of various factors on this phase and on the air-borne part of the take-off as a whole. The information was obtained from a series of step-by-step integrations, which defined the motion of the airplane during the transition and which were based on data derived from actual take-off tests of a Vervil… more
Date: October 26, 1937
Creator: Wetmore, J. W.
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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.
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Two-Dimensional Subsonic Compressible Flow Past Elliptic Cylinders

Description: "The method of Poggi is used to calculate, for perfect fluids, the effect of compressibility upon the flow on the surface of an elliptic cylinder at zero angle of attack and with no circulation. The result is expressed in a closed form and represents a rigorous determination of the velocity of the fluid at the surface of the obstacle insofar as the second approximation is concerned. Comparison is made with Hooker's treatment of the same problem according to the method of Janzen and Rayleight an… more
Date: February 11, 1938
Creator: Kaplan, Carl
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The unsteady lift of a wing of finite aspect ratio

Description: "Unsteady-lift functions for wings of finite aspect ratio have been calculated by correcting the aerodynamic inertia and the angle of attack of the infinite wing. The calculations are based on the operational method. The starting lift of the finite wing is found to be only slightly less than that of the infinite wing; whereas the final lift may be considerably less" (p. 1).
Date: June 15, 1939
Creator: Jones, Robert T.
open access

The variation with Reynolds number of pressure distribution over an airfoil section

Description: Pressures were simultaneously measured at 54 orifices distributed over the midspan section of a 5 by 30-inch rectangular model of the NACA 4412 airfoil in the variable-density tunnel. These measurements were made at 17 angles of attack from -20 degrees to 30 degrees for eight values of the effective Reynolds number form approximately 100,000 to 8,200,000. Accurate data were thus obtained for studying the variation of pressure distribution with Reynolds number. These results on the NACA 4412 sec… more
Date: July 14, 1937
Creator: Pinkerton, Robert M.
open access

The vertical wind tunnel of the National Advisory Committee for Aeronautics

Description: "The vertical open-throat wind tunnel of the National Advisory Committee for Aeronautics is described in this report. The tunnel was built mainly for studying the spinning characteristics of airplane models, but may be used as well for the usual types of wind-tunnel tests. A special spinning balance is being developed to measure the desired forces and moments with the model simulating the spin of an airplane. Satisfactory air flow has been attained with a velocity that is uniform over the jet t… more
Date: February 9, 1931
Creator: Wenzinger, Carl J. & Harris, Thomas A.
open access

Vibration response of airplane structures

Description: This report presents test results of experiments on the vibration-response characteristics of airplane structures on the ground and in flight. It also gives details regarding the construction and operation of vibration instruments developed by the National Advisory Committee for Aeronautics.
Date: May 10, 1934
Creator: Theodorsen, Theodore & Gelalles, A. G.
open access

The Weathering of Aluminum Alloy Sheet Materials Used in Aircraft

Description: This report presents the results of an investigation of the corrosion of aluminum alloy sheet materials used in aircraft. It has for its purpose to study the causes of corrosion embrittlement in duralumin-type alloys and the development of methods for its elimination. The report contains results, obtained in an extensive series of weather-exposure tests, which reveal the extent to which the resistance of the materials to corrosion was affected by variable factors in their heat treatment and by … more
Date: March 23, 1934
Creator: Mutchler, Willard
open access

Wind-Tunnel and Flight Tests of Slot-Lip Ailerons

Description: "The slot-lip ailerons developed by the NACA consist of a flap-type spoiler with an adjoining continuously open slot. The ailerons were developed in an investigation of the delayed response, or lag, of spoiler-type lateral controls. This report presents the results of tests of these slot-lip ailerons made on wing models in the 7 by 10-foot wind tunnel, on a Fairchild 22 airplane in the full-scale wind tunnel and in flight, and on the Weick W1-A airplane in flight" (p. 537).
Date: June 11, 1937
Creator: Shortal, Joseph A.
open access

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.
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Wind-Tunnel Investigation of an N.A.C.A. 23012 Airfoil with a Slotted Flap and Three Types of Auxiliary Flap

Description: An investigation was made in the N.A.C.A. 7- by 10-foot wind tunnel to determine the aerodynamic section characteristics of an N.A.C.A. 23012 airfoil with a single main slotted flap equipped successively with auxiliary flaps of the plain, split, and slotted types. A test installation was used in which an airfoil of 7-foot span was mounted vertically between the upper and the lower sides of the closed test section so that two-dimensional flow was approximated" (p. 699).
Date: October 31, 1938
Creator: Wenzinger, Carl J. & Gauvain, William E.
open access

Wind-Tunnel Investigation of an NACA 23012 Airfoil with Various Arrangements of Slotted Flaps

Description: "An investigation was made in the 7 by 10-foot wind tunnel and in the variable-density wind tunnel of the NACA 23012 airfoil with various slotted-flap arrangements. The purpose of the investigation in the 7 by 10-foot wind tunnel was to determine the airfoil section aerodynamic characteristics as affected by flap shape, slot shape, and flap location. The flap position for maximum lift; polars for arrangements favorable for take-off and climb; and complete lift, drag, and pitching-moment charact… more
Date: February 12, 1938
Creator: Wenzinger, Carl J. & Harris, Thomas A.
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Wind-tunnel investigation of NACA 23012, 23021, and 23030 airfoils with various sizes of split flap

Description: Report presents the results of an investigation made in the NACA 7 by 10-foot wind tunnel of large-chord NACA and 23021, and 23030 airfoils with split flaps 10, 20, 30, and 40 percent of the wing chord to determine the section aerodynamic characteristics of the airfoils as affected by airfoil thickness, flap chord, and flap deflection. The complete section aerodynamic characteristics of all the combinations tested are given in the form of graphs of lift, drag, and pitching-moment coefficients, … more
Date: March 10, 1939
Creator: Wenzinger, Carl J. & Harris, Thomas A.
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Wind-tunnel investigation of NACA 23012 airfoil with various arrangements of slotted flaps

Description: "An investigation was made in the NACA 7 by 10-foot wind tunnel of a large-chord NACA 23012 airfoil with several arrangements of 25.66 percent chord slotted flaps to determine the section aerodynamic characteristics as affected by slot shape, flap shape, flap location, and flap deflection. The flap position for maximum lift, the polars for arrangements considered favorable for take-off and climb, and the complete section aerodynamic characteristics for selected optimum arrangements were determi… more
Date: February 24, 1939
Creator: Wenzinger, Carl J. & Harris, Thomas A.
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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.
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Wind-Tunnel Investigation of Tapered Wings With Ordinary Ailerons and Partial-Span Split Flaps

Description: Report presents the results of an investigation made in the NACA 7 by 10-foot wind tunnel to determine the aerodynamic properties of tapered wings having partial-span flaps for high lift and ordinary ailerons for lateral control. Each of two Clark-y wings, tapered 5:1 and 5:3, was equipped with partial-span split flaps of two lengths and with ordinary ailerons extending from the outboard ends of the flap to the wing tips. Measurements of wing forces and moments and of aileron hinge moments were… more
Date: January 14, 1937
Creator: Wenzinger, Carl J.
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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.
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Wind-tunnel investigation of wings with ordinary ailerons and full-span external-airfoil flaps

Description: Report presents an investigation carried out in the NACA 7- by 10-foot wind tunnel of an NACA 23012 airfoil equipped, first, with a full-span NACA 23012 external-airfoil flap having a chord 0.20 of the main airfoil chord and with a full-span aileron with a chord 0.12 of the main airfoil chord on the trailing edge of the main airfoil and equipped second, with a 0.30-chord full-span NACA 23012 external-airfoil flap and a 0.13-chord full-span aileron. The results are arranged in three groups, the … more
Date: March 12, 1937
Creator: Platt, Robert C. & Shortal, Joseph A.
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Wind-Tunnel Research Comparing Lateral Control Devices, Particularly at High Angles of Attack 1: Ordinary Ailerons on Rectangular Wings

Description: "This report is the first in a series in which it is intended to compare the relative merits of all ordinary and some special forms of ailerons and other lateral control devices in regard to their effect on lateral controllability, lateral stability, and airplane performance. The comparisons are based on wind-tunnel test data, all the control devices being fitted to model wings having the same span, area, and airfoil section, and being subjected to the same series of force and rotation tests. T… more
Date: December 10, 1931
Creator: Weick, Fred E. & Wenzinger, Carl J.
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Wind-tunnel research comparing lateral control devices, particularly at high angles of attack 2: slotted ailerons and frise ailerons

Description: Three model wings, two with typical slotted ailerons and one with typical frise ailerons, have been tested as part of a general investigation on lateral control devices with particular reference to their effectiveness at high angles of attack, in the 7 by 10 foot wind tunnel of the National Advisory Committee for Aeronautics. Force tests, free-autorotation tests, and forced-rotation tests were made which show the effect of the various ailerons on the general performance of the wing, on the late… more
Date: February 18, 1932
Creator: Weick, Fred E. & Noyes, Richard W.
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Wind-Tunnel Research Comparing Lateral Control Devices, Particularly at High Angles of Attack 3: Ordinary Ailerons Rigged Up 10 Degrees When Neutral

Description: This report presents the results of wind-tunnel tests made on three model wings having different sizes of ordinary ailerons rigged up 10 degrees when neutral, the same models having previously been tested with the ailerons rigged even with the wings in the usual manner. One of the wings had ailerons of medium size, 25 per cent of the wing chord by 40 per cent of the semispan, one had long, narrow ailerons, and one had short, wide ones. These tests are part of a general investigation on lateral … more
Date: February 5, 1932
Creator: Weick, Fred E. & Wenzinger, Carl J.
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Wind-tunnel research comparing lateral control devices, particularly at high angles of attack 4: floating tip ailerons on rectangular wings

Description: "This report is the fourth of a series on systematic tests conducted which compares lateral control devices with particular reference to their effectiveness at high angles of attack. The present report covers tests with floating tip ailerons on rectangular Clark y wings. Ailerons of two profiles were tested - symmetrical and Clark y, both with adjustable trailing-edge flaps. Each form was tested at three hinge-axis locations, both with and without vertical end plates between the ailerons and th… more
Date: February 18, 1932
Creator: Weick, Fred E. & Harris, Thomas A.
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Wind-Tunnel Research Comparing Lateral Control Devices, Particularly at High Angles of Attack 5: Spoilers and Ailerons on Rectangular Wings

Description: "This report covers the fifth of a series of systematic investigations in which lateral control devices are compared with particular reference to their effectiveness at high angles of attack. The present report deals with tests of spoilers and ordinary ailerons on rectangular Clark Y wing models. In an effort to obtain satisfactory control throughout the entire angle-of-attack range that can be maintained in flight, various spoilers were tested in combination with two sizes of previously tested… more
Date: June 13, 1932
Creator: Weick, Fred E. & Shortal, Joseph A.
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