This system will be undergoing maintenance Monday, January 23 from 8:00 AM to 12:00 PM CST.

  You limited your search to:

  Partner: UNT Libraries Government Documents Department
 Serial/Series Title: NACA Technical Reports
 Collection: Technical Report Archive and Image Library
Wind tunnel balances

Wind tunnel balances

Date: January 1, 1920
Creator: Warner, Edward P & Norton, F H
Description: Report embodies a description of the balance designed and constructed for the use of the National Advisory Committee for Aeronautics at Langley Field, and also deals with the theory of sensitivity of balances and with the errors to which wind tunnel balances of various types are subject.
Contributing Partner: UNT Libraries Government Documents Department
Slip-stream corrections performance computation

Slip-stream corrections performance computation

Date: January 1, 1920
Creator: Warner, Edward P
Description: This report is an analysis of experiments performed by Eiffel on the air velocity in slip stream of a propeller, and also includes a theoretical discussion of the magnitude of the velocity in different propellers.
Contributing Partner: UNT Libraries Government Documents Department
The Limiting Velocity in Falling from a Great Height

The Limiting Velocity in Falling from a Great Height

Date: January 1, 1919
Creator: Wilson, Edwin Bidwell
Description: The purpose of this report is to give a simple treatment of the problem of calculating the final or limiting velocity of an object falling in vertical motion under gravity in a resisting medium. The equations of motion are easily set up and integrated when the density of the medium is constant and the resistance varies as the square of the velocity. The results show that the fundamental characteristics of the vertical motion under gravity in a resisting medium is the approach to a terminal or limiting velocity, whether the initial downward velocity is less or greater than the limiting velocity. This method can be used to calculate the terminal velocity of a bomb trajectory.
Contributing Partner: UNT Libraries Government Documents Department
Preliminary report on free flight tests

Preliminary report on free flight tests

Date: January 1, 1920
Creator: Warner, E P & Norton, F H
Description: Results are presented for a series of tests made by the Advisory Committee's staff at Langley Field during the summer of 1919 with the objectives of determining the characteristics of airplanes in flight and the extent to which the actual characteristics differ from those predicted from tests on models in the wind tunnel, and of studying the balance of the machines and the forces which must be applied to the controls in order to maintain longitudinal equilibrium.
Contributing Partner: UNT Libraries Government Documents Department
Bomb trajectories

Bomb trajectories

Date: January 1, 1920
Creator: Wilson, Edwin Bidwell
Description: The report is a mathematical treatise dealing with the trajectories of bombs of high terminal velocity, dropped from a great altitude.
Contributing Partner: UNT Libraries Government Documents Department
Construction of models for tests in wind tunnels

Construction of models for tests in wind tunnels

Date: January 1, 1920
Creator: Norton, F H
Description: Report deals with the methods of constructing aerofoils and all other parts of a model airplane, including discussion of the degree of accuracy.
Contributing Partner: UNT Libraries Government Documents Department
Diagrams of airplane stability

Diagrams of airplane stability

Date: January 1, 1921
Creator: Batemen, H
Description: In this report a study is made of the effect on longitudinal and lateral oscillations of an airplane of simultaneous variations in two resistance derivatives while the remainder of the derivatives are constant. The results are represented by diagrams in which the two variable resistance derivatives are used as coordinates, and curves are plotted along which the modulus of decay of a long oscillation has a constant value. The same type of analysis is also carried out for the stability of the parachute. In discussing the stability of the helicopter it is concluded that the gyroscopic effect on stability will be greater than in the case of the airplane.
Contributing Partner: UNT Libraries Government Documents Department
The efficiency of small bearings in instruments of the type used in aircraft

The efficiency of small bearings in instruments of the type used in aircraft

Date: January 1, 1921
Creator: Norton, F H
Description: This report deals with the construction and properties of bearings and pivots for use in instruments. The static and running friction for both thrust and radial loads was determined for a number of conical pivots and cylindrical and ball bearings. The static rocking friction was also measured for several conical and ball bearings under a heavy load, especially to determine their suitability for use in N. P. L. (National Physical Laboratory) type wind tunnel balance. In constructing conical pivots and sockets it was found that the pivots should be hardened and highly polished, preferably with a revolving lap, and that the sockets should be made by punching with a hardened and polished punch. It was found that for a light load the conical pivots give less friction than any other type, and their wearing qualities when hardened are excellent. Very small ball bearings are unsatisfactory because the proportional accuracy of the balls and races is not high enough to insure smooth running. For rocking pivots under heavy loads it was found that a ball-and-socket bearing, consisting of a hemispherical socket and a sphere of smaller diameter concentric with it, with a row of small balls resting between the two, was ...
Contributing Partner: UNT Libraries Government Documents Department
On the theory of laminar boundary layers involving separation

On the theory of laminar boundary layers involving separation

Date: January 1, 1934
Creator: Von Karman, TH & Millikan, C
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 wall. The final solution is obtained by joining these two solutions at the inflection points of the velocity profiles. The final solution is given in terms of a series of universal functions for a fairly broad class of potential velocity distributions outside of the boundary layer. Detailed calculations of the boundary layer characteristics are worked out for the case in which the potential velocity is a linear function of the distance from the upstream stagnation point. Finally, the complete separation point characteristics are determined for the boundary layer associated with a potential velocity distribution made up of two linear functions of the distance from the stagnation point. It appears that extensions of the detailed calculations to more complex ...
Contributing Partner: UNT Libraries Government Documents Department
Transonic flow past cone cylinders

Transonic flow past cone cylinders

Date: January 1, 1955
Creator: Solomon, George E
Description: Experimental results are presented for transonic flow post cone-cylinder, axially symmetric bodies. The drag coefficient and surface Mach number are studied as the free-stream Mach number is varied and, wherever possible, the experimental results are compared with theoretical predictions. Interferometric results for several typical flow configurations are shown and an example of shock-free supersonic-to-subsonic compression is experimentally demonstrated. The theoretical problem of transonic flow past finite cones is discussed briefly and an approximate solution of the axially symmetric transonic equations, valid for a semi-infinite cone, is presented.
Contributing Partner: UNT Libraries Government Documents Department
Moisture resistant finishes for airplane woods

Moisture resistant finishes for airplane woods

Date: January 1, 1921
Creator: Dunlap, M E
Description: This report describes briefly a series of experiments made at the Forest Products Laboratory, Madison, Wisconsin, to determine the comparative moisture resistance of linseed oil, impregnation treatments, condensation varnishes, oil varnishes, enamels, cellulose varnishes, rubber, electroplated and sprayed metal coatings, and metal-leaf coatings when applied to wood. All coatings except rubber and electroplated metal coatings, which were not developed sufficiently to make them practical, admitted moisture in varying degrees. The most effective and most practical coating was found to be that of aluminum leaf.
Contributing Partner: UNT Libraries Government Documents Department
The Design of Wind Tunnels and Wind Tunnel Propellers

The Design of Wind Tunnels and Wind Tunnel Propellers

Date: January 1, 1919
Creator: Warner, Edward P; Norton, F H & Hebbert, C M
Description: Report discusses the theory of energy losses in wind tunnels, the application of the Drzewiecki theory of propeller design to wind tunnel propellers, and the efficiency and steadiness of flow in model tunnels of various types.
Contributing Partner: UNT Libraries Government Documents Department
Airplane Stress Analysis

Airplane Stress Analysis

Date: January 1, 1918
Creator: Zahm, A F & Crook, L H
Description: Report presents stress analysis of individual components of an airplane. Normal and abnormal loads, sudden loads, simple stresses, indirect simple stresses, resultant unit stress, repetitive and equivalent stress, maximum steady load and stress are considered.
Contributing Partner: UNT Libraries Government Documents Department
Data on the design of plywood for aircraft

Data on the design of plywood for aircraft

Date: January 1, 1921
Creator: Elmendorf, Armin
Description: This report makes available data which will aid the designer in determining the plywood that is best adapted to various aircraft parts. It gives the results of investigations made by the Forest Products Laboratory of the United States Forest Service at Madison, Wisconsin, for the Army and Navy Departments, and is one of a series of reports on the use of wood in aircraft prepared by the Forest Products Laboratory for publication by the National Advisory Committee for Aeronautics. The object of the study was to determine, through comprehensive tests, the mechanical and physical properties of plywood and how these properties vary with density, number, thickness, arrangement of the plies and direction of grain of the plies.
Contributing Partner: UNT Libraries Government Documents Department
Wind tunnel studies in aerodynamic phenomena at high speed

Wind tunnel studies in aerodynamic phenomena at high speed

Date: January 1, 1921
Creator: Caldwell, F W & Fales, E N
Description: A great amount of research and experimental work has been done and fair success obtained in an effort to place airplane and propeller design upon an empirical basis. However, one can not fail to be impressed by the apparent lack of data available toward establishing flow phenomena upon a rational basis, such that they may be interpreted in terms of the laws of physics. With this end in view it was the object of the authors to design a wind tunnel differing from the usual type especially in regard to large power and speed of flow. This report describes the wind tunnel at Mccook Field and gives the results of experiments conducted in testing the efficiency of the wind tunnel.
Contributing Partner: UNT Libraries Government Documents Department
High-resolution autoradiography

High-resolution autoradiography

Date: January 1, 1955
Creator: Towe, George C; Gomberg, Henry J & Freemen, J W
Description: This investigation was made to adapt wet-process autoradiography to metallurgical samples to obtain high resolution of segregated radioactive elements in microstructures. Results are confined to development of the technique, which was perfected to a resolution of less than 10 microns. The radioactive samples included carbon-14 carburized iron and steel, nickel-63 electroplated samples, a powder product containing nickel-63, and tungsten-185 in N-155 alloy.
Contributing Partner: UNT Libraries Government Documents Department
Pressure distribution over the wings of an MB-3 airplane in flight

Pressure distribution over the wings of an MB-3 airplane in flight

Date: January 1, 1925
Creator: Norton, F H
Description: This investigation was carried out to determine the distribution of load over the wings of a high speed airplane under all conditions of flight. In particular it was desired to find the pressure distribution during level flight, over the portions of the wings in the slipstream and, during violent maneuvers, over the entire wing surface. The method used consisted in connecting a number of holes in the surface of the wings to recording multiple manometers mounted in the fuselage of the airplane. In this way simultaneous records could be taken on all of the holes for any desired length of time. (author).
Contributing Partner: UNT Libraries Government Documents Department
Wing spar stress charts and wing truss proportions

Wing spar stress charts and wing truss proportions

Date: January 1, 1926
Creator: Warner, Edward P
Description: In order to simplify the calculation of beams continuous over three supports, a series of charts have been calculated giving the bending moments at all the critical points and the reactions at all supports for such members. Using these charts as a basis, calculations of equivalent bending moments, representing the total stresses acting in two bay-wing trusses of proportions varying over a wide range, have been determined, both with and without allowance for column effect. This leads finally to the determination of the best proportions for any particular truss or the best strut locations in any particular airplane. The ideal proportions are found to vary with the thickness of the wing section used, the aspect ratio, and the ratio of gap to chord.
Contributing Partner: UNT Libraries Government Documents Department
Experimental research on air propellers  IV

Experimental research on air propellers IV

Date: January 1, 1921
Creator: Durand, W F & Lesley, E P
Description: This report states the results of investigations made upon numerous propeller models at the request of the Subcommittee on Aerodynamics, and contains valuable data for those interested in the design of air propellers.
Contributing Partner: UNT Libraries Government Documents Department
The decay of a simple eddy

The decay of a simple eddy

Date: January 1, 1923
Creator: Bateman, H
Description: The principal result obtained in this report is a generalization of Taylor's formula for a simple eddy. The discussion of the properties of the eddy indicates that there is a slight analogy between the theory of eddies in a viscous fluid and the quantum theory of radiation. Another exact solution of the equations of motion of viscous fluid yields a result which reminds one of the well-known condition for instability in the case of a horizontally stratified atmosphere.
Contributing Partner: UNT Libraries Government Documents Department
The six-component wind balance

The six-component wind balance

Date: January 1, 1923
Creator: Zahm, A F
Description: Dr. Zahm's report is a description of the six-component wind-tunnel balance in use at the Aerodynamic Laboratory, Washington Navy Yard. The description of the balance gives the mechanical details and the method of operation, and is accompanied by line drawings showing the construction of the balance. The balance is of particular interest, as it allows the model to be set up quickly and accurately in roll, pitch, and yaw, without stopping the wind. It is possible to measure automatically, directly, and independently the drag, cross-wind force, and lift; also the rolling, pitching, and yawing moments. It is also possible to make the balance self-recording.
Contributing Partner: UNT Libraries Government Documents Department
Standard atmosphere

Standard atmosphere

Date: January 1, 1923
Creator: Gregg, Willis Ray
Description: This report was prepared at the request of the National Advisory Committee for Aeronautics and discusses the need of a standard set of values of pressure, temperature and density at various altitudes and points out the desirability of adopting such values as are most in accord with actual average conditions, in order that corrections in individual cases may be as small as possible. To meet this need, so far as the united states is concerned, all free-air observations obtained by means of kites and balloons at several stations in this country near latitude 40 degrees N., have been used, and average values of pressure, temperature, and density, based upon those observations, have been determined for summer, winter, and the year, and for all altitudes up to 20,000 meters (65,000 feet). These values are presented in tables and graphs in both metric and english units; and in the tables of densities there are also included values of density for other parts of the world, more particularly for Europe. A comparison with these values shows that, except in the lowest levels, the agreement is very satisfactory.
Contributing Partner: UNT Libraries Government Documents Department
Internal stresses in laminated construction

Internal stresses in laminated construction

Date: January 1, 1923
Creator: Heim, A L; Knauss, A C & Seutter, Louis
Description: This report reviews the procedure employed in an investigation of the sources and influence of internal stresses in laminated construction, and discusses the influence of shrinkage and swelling stresses caused by atmospheric conditions upon the tensile strength across grain in laminated construction with special reference to airplane propellers. The investigation covered three sources of internal stress, namely, the combination of plain-sawed and quarter-sawed material in the same construction, the gluing together of laminations of different moisture contents, and the gluing together of laminations of different densities. Glued specimens and free specimens, made up under various manufacturing conditions, were subjected to various climatic changes inducing internal stresses and then were tested.
Contributing Partner: UNT Libraries Government Documents Department
Experimental research on air propellers V

Experimental research on air propellers V

Date: January 1, 1923
Creator: Durand, W F & Lesley, E P
Description: In previous reports on experimental research on air propellers, by W. F. Durand and E. P. Lesley, as contained in the National Advisory Committee for Aeronautics reports nos. 14, 30, and 64, the investigations were made progressively and each without reference to results given in preceding reports and covering only information relating to forms perhaps adjacent in geometrical form and proportion. This report is a review of the entire series of results of the preceding reports with a view of examining through graphical and other appropriate means the nature of the history of the characteristics of operation as related to the systematic variations in characteristics of forms, etc., through the series of such characteristics.
Contributing Partner: UNT Libraries Government Documents Department