Technical Report Archive and Image Library (TRAIL) - 274 Matching Results

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Supplies and production of aircraft woods

Description: The purpose of this report is to present in brief form such information as is available regarding the supplies of the kinds of wood that have been used or seem likely to become important in the construction of airplanes, and the amount of lumber of each species normally put on the market each year. A general statement is given of the uses to which each kind of wood is or may be put.
Date: January 1, 1920
Creator: Sparhawk, W N
Partner: UNT Libraries Government Documents Department

Diaphragms for Aeronautic Instruments

Description: This investigation was carried out at the request of the National Advisory Committee for Aeronautics and comprises an outline of historical developments and theoretical principles, together with a discussion of expedients for making the most effective use of existing diaphragms actuated by the hydrostatic pressure form an essential element of a great variety instruments for aeronautic and other technical purposes. The various physical data needed as a foundation for rational methods of diaphragm design have not, however, been available hitherto except in the most fragmentary form.
Date: January 1, 1924
Creator: Hersey, M D
Partner: UNT Libraries Government Documents Department

Performance of B. M. W. 185-Horsepower Airplane Engine

Description: This report deals with the results of a test made upon a B. M. W. Engine in the altitude chamber of the Bureau of Standards, where controlled conditions of temperature and pressure can be made to simulate those of the desired altitude. A remarkably low value of fuel consumption - 041 per B. H. P. hour - is obtained at 1,200 revolutions per minute at an air density of 0.064 pound per cubic foot and a brake thermal efficiency of 33 per cent and an indicated efficiency of 37 per cent at the above speed and density. In spite of the fact that the carburetor adjustment does not permit the air-fuel ratio of maximum economy to be obtained at air densities lower than 0.064, the economy is superior to most engines tested thus far, even at a density lower than 0.064, the economies superior to most engines tested thus far, even at a density (0.03) corresponding to an altitude of 25,000 feet. The brake mean effective pressure even at full throttle is rather low. Since the weight of much of the engine is governed more by its piston displacement than by the power developed, a decreased mean effective pressure usually necessitates increased weight per horsepower. The altitude performance of the engine is, in general, excellent, and its low fuel consumption is the outstanding feature of merit.
Date: January 1, 1923
Creator: Sparrow, S W
Partner: UNT Libraries Government Documents Department

Standardization tests of NACA no. 1 wind tunnel

Description: The tests described in this report were made in the 5-foot atmospheric wind tunnel of the National Advisory Committee for Aeronautics, at Langley Field. The primary objective of collecting data on the characteristics of this tunnel for comparison with those of others throughout the world, in order that, in the future, the results of tests made in all the principle laboratories may be interpreted, compared, and coordinated on a basis of scientifically established relationships, a process hitherto impossible due to the lack of comparable data. The work includes tests of a disk, spheres, cylinders, and airfoils, explorations of the test section for static pressure and velocity distribution, and determination of the variations of air flow direction throughout the operating range of the tunnel. (author).
Date: January 1, 1925
Creator: Reid, Elliott G
Partner: UNT Libraries Government Documents Department

The calculated performance of airplanes equipped with supercharging engines

Description: In part one of this report are presented the theoretical performance curves of an airplane engine equipped with a supercharging compressor. In predicting the gross power of a supercharging engine, the writer uses temperature and pressure correction factors based on experiments made at the Bureau of Standards (NACA report nos. 45 and 46). Means for estimating the temperature rise in the compressor are outlined. Part two of this report presents an estimation of the performance curves of an airplane fitted with a supercharging engine. A supercharging installation suitable for commercial use is described, and it is shown that with the use of the compressor a great saving in fuel and a considerable increase in carrying capacity can be effected simultaneously. In an appendix the writer derives a theoretical formula for the correction of the thrust coefficient of an airscrew to offset the added resistance of the airplane due to the slip-stream effect.
Date: January 1, 1921
Creator: Kemble, E C
Partner: UNT Libraries Government Documents Department

An investigation of the aerodynamic characteristics of an airplane equipped with several different sets of wings

Description: This investigation was conducted by the National Advisory Committee for Aeronautics at Langley Field, Va., at the request of the Army Air Corps, for the purpose of comparing the full scale lift and drag characteristics of an airplane equipped with several sets of wings of commonly used airfoil sections. A Sperry Messenger Airplane with wings of R.A.F.-15, U.S.A.-5, U.S.A.-27, and Gottingen 387 airfoil sections was flown and the lift and drag characteristics of the airplane with each set of wings were determined by means of glide tests. The results are presented in tabular and curve form. (author).
Date: January 1, 1929
Creator: Crowley, J W , Jr & Green, M W
Partner: UNT Libraries Government Documents Department

Dynamic stability as affected by the longitudinal moment of inertia

Description: In a recent Technical Note (NACA-TN-115, October, 1922), Norton and Carrol have reported experiments showing that a relatively large (15 per cent) increase in longitudinal moment of inertia made no noticeable difference in the stability of a standard SE-5A airplane. They point out that G. P. Thomson, "Applied Aeronautics," page 208, stated that an increase in longitudinal moment of inertia would decrease the stability. Neither he nor they make any theoretical forecast of the amount of decrease. Although it is difficult, on account of the complications of the theory of stability of the airplane, to make any accurate forecast, it is the purpose of this report to attempt a discussion of the matter theoretically with reference to finding a rough quantitative estimate.
Date: January 1, 1924
Creator: Wilson, Edwin B.
Partner: UNT Libraries Government Documents Department

An investigation of the coefficient of discharge of liquids through small round orifices

Description: The work covered by this report was undertaken in connection with a general investigation of fuel injection engine principles as applied to engines for aircraft propulsion, the specific purpose being to obtain information on the coefficient of discharge of small round orifices suitable for use as fuel injection nozzles. Values for the coefficient were determined for the more important conditions of engine service such as discharge under pressures up to 8,000 pounds per square inch, at temperatures between 80 degrees and 180 degrees F. And into air compressed to pressures up to 1,000 pounds per square inch. The results show that the coefficient ranges between 0.62 and 0.88 for the different test conditions between 1,000 and 8,000 pounds per square inch hydraulic pressure. At lower pressures the coefficient increases materially. It is concluded that within the range of these tests and for hydraulic pressures above 1,000 pound per square inch the coefficient does not change materially with pressure or temperature; that it depends considerably upon the liquid, decreases with increase in orifice size, and increases in the case of discharge into compressed air until the compressed-air pressure equals approximately three-tenths of the hydraulic pressure, beyond which pressure ratio it remains practically constant.
Date: January 1, 1926
Creator: Joachim, W F
Partner: UNT Libraries Government Documents Department

A full-scale investigation of ground effect

Description: This report describes flight tests which were made with the Vought VE-7 airplane to determine the effects of flying close to the ground. It is found that the drag of an airplane is materially reduced upon approaching the ground and that the reduction may be satisfactorily calculated according to theoretical formulas. Several aspects of ground effect which have had much discussion are explained.
Date: January 1, 1928
Creator: Reid, Elliott G
Partner: UNT Libraries Government Documents Department

Moisture resistant finishes for airplane woods

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.
Date: January 1, 1921
Creator: Dunlap, M E
Partner: UNT Libraries Government Documents Department

Data on the design of plywood for aircraft

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.
Date: January 1, 1921
Creator: Elmendorf, Armin
Partner: UNT Libraries Government Documents Department

Wind tunnel studies in aerodynamic phenomena at high speed

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.
Date: January 1, 1921
Creator: Caldwell, F W & Fales, E N
Partner: UNT Libraries Government Documents Department

Experimental research on air propellers IV

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.
Date: January 1, 1921
Creator: Durand, W F & Lesley, E P
Partner: UNT Libraries Government Documents Department

The decay of a simple eddy

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.
Date: January 1, 1923
Creator: Bateman, H
Partner: UNT Libraries Government Documents Department

The six-component wind balance

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.
Date: January 1, 1923
Creator: Zahm, A F
Partner: UNT Libraries Government Documents Department

Standard atmosphere

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.
Date: January 1, 1923
Creator: Gregg, Willis Ray
Partner: UNT Libraries Government Documents Department

Tests on air propellers in yaw

Description: This report contains the results of tests to determine the thrust (pull) and torque characteristics of air propellers in movement relative to the air in a line oblique to the line of the shaft, and specifically when such angle of obliquity is large, as in the case of helicopter flight with the propeller serving for both sustentation and traction.
Date: January 1, 1923
Creator: Durand, W F & Lesley, E P
Partner: UNT Libraries Government Documents Department

Bomb trajectories

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

Diagrams of airplane stability

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.
Date: January 1, 1921
Creator: Batemen, H
Partner: UNT Libraries Government Documents Department

Internal stresses in laminated construction

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.
Date: January 1, 1923
Creator: Heim, A L; Knauss, A C & Seutter, Louis
Partner: UNT Libraries Government Documents Department

Experimental research on air propellers V

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.
Date: January 1, 1923
Creator: Durand, W F & Lesley, E P
Partner: UNT Libraries Government Documents Department

Interaction between air propellers and airplane structures

Description: The purpose of this investigation was the determination of the character and amount of interaction between air propellers as usually mounted on airplanes and the adjacent parts of the airplane structure - or, more specifically, those parts of the airplane structure within the wash of the propeller, and capable of producing any significant effect on propeller performance. In report no. 177 such interaction between air propellers and certain simple geometrical forms was made the subject of investigation and report. The present investigation aims to carry this general study one stage further by substituting actual airplane structures for the simple geometrical forms. From the point of view of the present investigation, the airplane structures, viewed as an obstruction in the wake of the propeller, must also be viewed as a necessary part of the airplane and not as an appendage which might be installed or removed at will. (author).
Date: January 1, 1927
Creator: Durand, W F
Partner: UNT Libraries Government Documents Department