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  Partner: UNT Libraries Government Documents Department
 Decade: 1920-1929
 Collection: National Advisory Committee for Aeronautics Collection
Langley Field wind tunnel apparatus

Langley Field wind tunnel apparatus

Date: October 1, 1921
Creator: Bacon, D L
Description: The difficulties experienced in properly holding thin tipped or tapered airfoils while testing on an N.P.L. type aerodynamic balance even at low air speeds, and the impossibility of holding even solid metal models at the high speeds attainable at the National Advisory Committee's wind tunnel, necessitated the design of a balance which would hold model airfoils of any thickness and at speeds up to 150 m.p.h. In addition to mechanical strength and rigidity, it was highly desirable that the balance readings should require a minimum amount of correction and mathematical manipulation in order to obtain the lift and drag coefficients and the center of pressure. The balance described herein is similar to one in use at the University of Gottingen, the main difference lying in the addition of a device for reading the center of pressure directly, without the necessity of any correction whatsoever. Details of the design and operation of the device are given.
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Similitude tests on wind sections

Similitude tests on wind sections

Date: March 1, 1921
Creator: Bacon, D L
Description: None
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Tests of rotating cylinders

Tests of rotating cylinders

Date: December 1, 1924
Creator: Reid, Elliott G
Description: Tests were made in the no. 1 wind tunnel at Langley Memorial Aeronautical Laboratory to determine the air forces acting on rotating cylinders with axes perpendicular to the direction of motion. One cylinder had a circular cross-section, the other that of a greek cross.
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Wall interference in closed type wind tunnels

Wall interference in closed type wind tunnels

Date: March 1, 1927
Creator: Higgins, George J
Description: A series of tests has been conducted by the National Advisory Committee for Aeronautics, in the variable density wind tunnel on several airfoils of different sizes and sections to determine the effect of tunnel wall interference and to determine a correction which can be applied to reduce the error caused thereby. The use of several empirical corrections was attempted with little success. The Prandtl theoretical correction gives the best results and its use is recommended for correcting closed wind tunnel results to conditions of free air.
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A warning concerning the take-off with heavy load

A warning concerning the take-off with heavy load

Date: July 1, 1927
Creator: Reid, Elliott G & Carroll, Thomas
Description: A successful take-off can be made with an airplane so heavily loaded that it cannot climb to a height greater than the span of its wings. The explanation is that the power required to maintain level flight at an altitude of the order of the wing span may be as much as 50 per cent greater than that necessary when the airplane is just clear of the ground. The failure of heavily loaded airplanes to continue climbing at the rate attained immediately after the actual take-off is a grave hazard and has resulted in great risk or catastrophe in three notable cases which are cited.
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A study of static stability of airships

A study of static stability of airships

Date: September 1, 1924
Creator: Rizzo, Frank
Description: The first section deals with the theoretical side of statical stability of airships in general. The second section deals with preliminary tests of the model and experiments for the determination of effects due to change of tail area, aspect ratio, tail form, and tail thickness.
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Mass distribution and performance of free flight models

Mass distribution and performance of free flight models

Date: October 1, 1927
Creator: Scherberg, Max & Rhode, R V
Description: This note deals with the mass distribution and performance of free flight models. An airplane model which is to be used in free flight tests must be balanced dynamically as well as statically, e.g., it must not only have a given weight and the proper center of gravity but also a given ellipsoid of inertia. Equations which relate the motions of an airplane and its model are given. Neglecting scale effect, these equations may be used to predict the performance of an airplane, under the action of gravity alone, from data obtained in making dropping tests of a correctly balanced model.
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Notes on longitudinal stability and balance

Notes on longitudinal stability and balance

Date: April 1, 1920
Creator: Warner, E P
Description: None
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A mechanical device for illustrating airplane stability

A mechanical device for illustrating airplane stability

Date: December 1, 1921
Creator: Norton, F H
Description: An instrument is described which will illustrate completely in a qualitative sense the longitudinal stability characteristics of an airplane. The instrument is primarily of use for the lecture room, but it is hoped that ultimately it will be possible to obtain quantitative results from it.
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The time lag and interval of discharge with a spring actuated fuel injection pump

The time lag and interval of discharge with a spring actuated fuel injection pump

Date: September 1, 1923
Creator: Matthews, Robertson & Gardiner, A W
Description: Discussed here is research on a spring activated fuel pump for solid or airless injection with small, high speed internal combustion engines. The pump characteristics under investigation were the interval of fuel injection in terms of degrees of crank travel and in absolute time, the lag between the time the injection pump plunger begins its stroke and the appearance of the jet at the orifice, and the manner in which the fuel spray builds up to a maximum when the fuel valve is opened, and then diminishes.
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Discharge characteristics of a high speed fuel injection system

Discharge characteristics of a high speed fuel injection system

Date: February 1, 1925
Creator: Matthews, Robertson
Description: Discussed here are some discharge characteristics of a fuel injection system intended primarily for high speed service. The system consisted of a cam actuated fuel pump, a spring loaded automatic injection valve, and a connecting tube.
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Pressure distribution on the nose of an airship in circling flight

Pressure distribution on the nose of an airship in circling flight

Date: August 1, 1925
Creator: Fairbanks, Karl J
Description: In recent tests on the pressures occurring on the envelope and control surfaces of the naval airship C-7, it was noted that the pressures on the nose of the airship, while flying in level circling flight, were symmetrically distributed. Such a condition can only occur when the nose of the airship is pointed directly into the wind, and to accomplish this in circling flight, the axis of the airship must then be parallel to the direction of the motion of the nose. The question was raised as to whether the same conditions occur generally on all airships in circling flight. It appears that airships flying in a constant, level, circling flight path will generally head very closely into the wind, and any deviation will be so slight that the distribution of pressure over the nose will be but slightly, if at all, changed from a symmetrical distribution.
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Pressure distribution on wing ribs of the VE-7 and TS airplanes in flight

Pressure distribution on wing ribs of the VE-7 and TS airplanes in flight

Date: October 1, 1927
Creator: Rhode, R V
Description: This paper is the first of a series of notes, each of which presents the complete results of pressure distribution tests made by the National Advisory Committee for Aeronautics, on single-wing ribs of the VE-7 and TS airplanes for a particular condition of flight. The level flight results are presented here in the form of curves and show the comparison between the pressure distribution over a representative thin wing, R.A.F.-15, and a moderately thick wing, U.S.A.-27, throughout the range of angle of attack.
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The effect on performance of a cutaway center section

The effect on performance of a cutaway center section

Date: January 1, 1928
Creator: Carroll, Thomas
Description: The assumption is made that a skeleton or cutaway center section is desirable for forward vision and to determine the effect of such mutilation upon performance the following work was done. The airplane used was a Vought VE-7 and in addition to the cutaway center section a system of end plates or fins was installed. Various conditions and combinations were investigated in level flight and in climb. It is found that the greatest difference in the conditions investigated was a drop of 12.5 per cent in a 10-minute climb while the effect upon level speeds was negligible.
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An investigation on the effect of raked wing tips

An investigation on the effect of raked wing tips

Date: November 1, 1921
Creator: Norton, F H
Description: This investigation was carried out by request of the United States Air Service in the wind tunnel of the Massachusetts Institute of Technology. The results are here published by the National Advisory Committee for Aeronautics as it is thought that they may be of general interest. Wings of the R.A.F. 6 section are tested with various angles of rake, and it is found that although rake has very little effect, a positive or negative rake of 30 degrees is the best.
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The NACA three component accelerometer

The NACA three component accelerometer

Date: October 1, 1922
Creator: Reid, H J E
Description: A new instrument known as the NACA three component accelerometer is described in this note. This instrument was designed by the technical staff of the NACA for recording accelerations along three mutually perpendicular axes, and is of the same type as the NACA single component accelerometer with the addition of two springs and a few minor improvements such as a pump for filling the dash-pots and a convenient method for aligning the springs. This note includes a few records as well as photographs of the instrument itself.
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NACA flight-path angle and air-speed recorder

NACA flight-path angle and air-speed recorder

Date: April 1, 1926
Creator: Coleman, Donald G
Description: A new trailing bomb-type instrument for photographically recording the flight-path angle and air speed of aircraft in unaccelerated flight is described. The instrument consists essentially of an inclinometer, air-speed meter and a film-drum case. The inclinometer carries an oil-damped pendulum which records optically the flight-path angle upon a rotating motor-driven film drum. The air-speed meter consists of a taut metal diaphragm of high natural frequency which is acted upon by the pressure difference of a Prandtl type Pitot-static tube. The inclinometer record and air-speed record are made optically on the same sensitive film. Two records taken by this instrument are shown.
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The NACA CYH airfoil section

The NACA CYH airfoil section

Date: June 1, 1926
Creator: Higgins, George J
Description: The NACA CYH airfoil section is described and its aerodynamic characteristics are given as tested in the NACA variable density wind tunnel at twenty atmosphere pressure. This section has a low drag, a high maximum lift, and a small travel of center of pressure.
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Model supports and their effects on the results of wind tunnel tests

Model supports and their effects on the results of wind tunnel tests

Date: February 1, 1923
Creator: Bacon, David L
Description: The airflow about a model while being tested is often sufficiently affected by the model support to lead to erroneous conclusions unless appropriate corrections are used. In this paper some new material on the subject is presented, together with a review of the airfoil support corrections used in several other laboratories.
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The N.A.C.A. recording tachometer and angle of attack recorder

The N.A.C.A. recording tachometer and angle of attack recorder

Date: August 1, 1923
Creator: Reid, H J E
Description: This note contains photos and descriptions of airplane flight apparatus for use in conjunction with a recording galvanometer. In measuring the angle of attack a variable resistance is used, being controlled by a vane in the airstream. Thus it is only necessary to measure the change of resistance.
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An investigation of the characteristics of steel diaphragms for automatic fuel-injection valves

An investigation of the characteristics of steel diaphragms for automatic fuel-injection valves

Date: April 1, 1926
Creator: Joachim, W F
Description: This research on steel diaphragms was undertaken at the Langley Memorial Aeronautical Laboratory, as a part of a general investigation on fuel injection engines for aircraft. The work determined the load-deflection, load- deformation and hysteresis characteristics for single diaphragms having thicknesses from 0.00s inch to 0.012 inch, and for similar diaphragms tested in multiple having total thicknesses from 0.012 inch to 0.180 inch. The elastic limit loads and deflections, and rupture points of single diaphragms were also determined. Some work was done on diaphragms having central orifices in order to determine the effect of orifice diameter upon the load deflection characteristics.
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Propeller design - a simple system based on model propeller test data III

Propeller design - a simple system based on model propeller test data III

Date: May 1, 1926
Creator: Wieck, Fred E
Description: This report, the third of a series of four, describes a simple system for designing propellers of a standard form. In this report, the system is based on tests of a family of model propellers of standard Navy form, the data from which have been extended by means of calculations to cover the complete range likely to be found in practice. However, it can be worked out for any family having propellers of one general form.
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Propeller design IV : a simple method for determining the strength of propellers

Propeller design IV : a simple method for determining the strength of propellers

Date: June 1, 1926
Creator: Weick, Fred E
Description: The object of this report, the last of a series of four on propeller design, is to describe a simple method for determining whether the strength of a propeller of a standard form is sufficient for safe operation. An approximate method of stress analysis is also given.
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Propeller design: extension of test data on a family of model propellers by means of the modified blade element theory II

Propeller design: extension of test data on a family of model propellers by means of the modified blade element theory II

Date: May 1, 1926
Creator: Weick, Fred E
Description: This report is the second of a series of four on propeller design, and describes the method used to extend the data obtained from tests on a family of thirteen model propellers to include all propellers of the same form likely to be met in practice. This necessitates the development of a method of propeller analysis which when used to calculate the powers and efficiencies gives results which check the tests throughout their range.
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