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Condensed Data on the Aircraft Engines of the World
This compilation of the outstanding characteristics of the available aircraft engines of the world was prepared as a compact ready reference for desk use. It does not pretend to be anything but a skeleton outline of the characteristics of engines reported in the technical press as being in either the experimental, development, or production stage. At present progress is quite rapid and by the time this compilation is disseminated new models may have superseded those listed, or changes may have been made which will entirely change the characteristics given" (p. 1).
Correcting Engine Tests for Humidity
Note presenting tests using a multicylinder engine to determine the effect that atmospheric humidity has on some phases of engine performance. Three test series with different types of fuel were carried out. The results indicate that failure to allow for the effect of differences in atmospheric humidity may introduce errors as great as would be occasioned by failure to allow for changes in barometric pressure.
Corrosion Embrittlement of Duralumin. V: Results of Weather-Exposure Tests
In a series of weather exposure tests of sheet duralumin, upon which accelerated corrosion tests in the laboratory by the wet-and-dry corrosion method in a sodium chloride solution has already been carried out, a close parallelism between the results of the two kinds of tests was found to exist. The exposure tests showed that the lack of permanence of sheet duralumin is largely, if not entirely, due to corrosion. A corrosion attack of an intercrystalline nature is very largely responsible for the degree of embrittlement produced.
Corrosion Embrittlement of Duralumin. VI: The Effect of Corrosion Accompanied by Stress on the Tensile Properties of Sheet Duralumin
The effect of corrosion on the tensile properties of duralumin while stressed is shown in graphical form. According to the test results, duralumin sheet, coated with aluminum, maintains its initial properties unimpaired for corrosion periods as long as 60 days with an applied tensile stress as high as 20,000 lb/sq.in., which is approximately one-half the stress corresponding to the yield point as defined here. In these tests, that material which had been heat-treated by being quenched in cold water, though far inferior to similar material having the aluminum coating, was superior to the sheet material which was heat treated by being quenched in hot water.
Curves Showing Column Strength of Steel and Duralumin Tubing
Given here are a set of column strength curves that are intended to simplify the method of determining the size of struts in an airplane structure when the load in the member is known. The curves will also simplify the checking of the strength of a strut if the size and length are known. With these curves, no computations are necessary, as in the case of the old-fashioned method of strut design. The process is so simple that draftsmen or others who are not entirely familiar with mechanics can check the strength of a strut without much danger of error.
The Drag and Interference of a Nacelle in the Presence of a Wing
A wing interference investigation was conducted to determine why the N.A.C.A. cowling did not yield the expected increase in speed when adapted to the outboard nacelles of trimotored airplanes. The results indicate that the drag and interference of the engine nacelle with the cowling, when combined with a thick wing, can be reduced from its value as originally applied by changing its position and fairing it into the wing.
The Effect of Fuel Consumption on Cylinder Temperatures and Performance of a Cowled Wright J-5 Engine
Given here are the results of tests made to determine the effect of fuel consumption on the cylinder temperatures and the performance of a cowled Wright J-5 engine. The results of these tests indicate that enriching the mixture by increasing the carburetor size results in a reduction in cylinder head and barrel temperatures. The cylinders shielded by the magnetos or the points on the cylinder that do not receive a free flow of cooling air increase most rapidly in temperature as the mixture is leaned.
The effect of the wings of single engine airplanes on propulsive efficiency as shown by full scale wind tunnel tests
An investigation was conducted to determine the effect of the wings on propulsive efficiency. The wings are shown to cause a reduction of 1 percent to 3 percent in propulsive efficiency, which is about the same for monoplane as well as biplane wings.
The Formation of Ice Upon Airplanes in Flight
This report describes the atmospheric conditions under which ice is formed upon the exposed parts of airplanes in flight. It identifies the formation found under different conditions, and describes some studies of preventative means.
Full Scale Investigation of the Drag of a Wing Radiator
Tests were made on the 1927 Williams racer in order to determine the effect of the wing radiator on the airfoil characteristics. It was found that the radiator doubled the minimum drag of the portion of the wing it covered, and also reduced the lift somewhat.
The Impact on Seaplane Floats During Landing
"In order to make a stress analysis of seaplane floats, and especially of the members connecting the floats with the fuselage, it is of great importance to determine the maximum pressure acting on the floats during landing. Here, the author gives a formula for maximum pressures during landing that permits one to apply experimental results to different bodies and different velocities. The author notes that the formula checks very well with experimental results" (p. 1).
A New Method for the Prediction of Airplane Performance
A new method for the prediction of airplane performance in level and climbing flight, together with complete information regarding propeller speeds, is described in this report. Developed from Bairstow's system and making use of American absolute coefficients, this method has advantages of simplicity and brevity.
Pressure Distribution on a Slotted R.A.F. 31 Airfoil in the Variable Density Wind Tunnel
Measurements were made in the variable density wind tunnel to determine the pressure distribution over one section of a R.A.F. 31 airfoil with a leading edge slot fully open. To provide data for the study of scale effect on this type of airfoil, the tests were conducted with air densities of approximately one and twenty atmospheres.
Some effects of air flow on the penetration and distribution of oil sprays
Tests were made to determine the effects of air flow on the characteristics of fuel sprays from fuel injection valves. Curves and photographs are presented showing the airflow throughout the chamber and the effects of the air flow on the fuel spray characteristics. It was found that the moving air had little effect on the spray penetration except with the 0.006 inch orifice. The moving air did, however, affect the oil particles on the outside of the spray cone. After spray cut-off, the air flow rapidly distributed the atomized fuel throughout the spray chamber.
Some Experiments on Autorotation of an Airfoil
"These experiments show that the rate of auto rotation of a monoplane airfoil is reduced by sweepback, ceasing entirely when the sweepback is 30 degrees. In addition a very serious increase in rate and range of auto rotation with yaw is shown" (p. 1).
Some Studies on the Aerodynamic Effect of the Gap Between Airplane Wings and Fuselages
"The general result indicated by this study is that if desirable from any viewpoint the gap between wing and fuselage may be closed without detrimental aerodynamic effects, and with a given monoplane there is less drag if the wing is directly on top of the fuselage than if it is parasol" (p. 1).
Sphere Drag Tests in the Variable Density Wind Tunnel
The air forces on a twenty-centimeter sphere were measured after it had been rebuilt as an open throat type. The results from tests made at widely different densities and airspeeds and also on a smaller sphere are given. The conclusions are that approximately the same drag coefficient is obtained at a given value of the Reynolds number irrespective of what combination of the variables is used to obtain that value and that the turbulence of the air stream at the test section, as measured by the critical Reynolds number of a sphere, is less for the new tunnel than for the old one.
Spiral Tendency in Blind Flying
"The flight path followed by an airplane which was being flown by a blindfolded pilot was observed and recorded. When the pilot attempted to make a straight-away flight there was a tendency to deviate from the straight path and to take up a spiral one" (p. 1).
Strength of Tubing Under Combined Axial and Transverse Loading
Note presenting a systematic study of the strength of duralumin and chrome-molybdenum steel round tubing in combined transverse and axial loading. A description of the formulas that are the groundwork for the study as well as the results of the tests are provided.
Tests of Four Racing Type Airfoils in the Twenty-Foot Propeller Research Tunnel
Tests were made on four racing type airfoils, the N-9, N-38, C-62, and N-46, in order to determine the high speed characteristics of the wings. The results indicate that the N-46 has about 12 percent lower minimum drag than the regular C-62 section, and that both the N-38 and N-46 have the same exceptionally low minimum drag coefficient.
The Use of Wheel Brakes on Airplanes
The results of tests to determine the effect of wheel brakes on the landing run of an airplane under conditions of load and at various wind velocities are presented.
Viscosity of diesel engine fuel oil under pressure
In the development of Diesel engine fuel injection systems it is necessary to have an approximate knowledge of the absolute viscosity of the fuel oil under high hydrostatic pressures. This report presents the results of experimental tests conducted by Mr. Jackson Newton Shore, utilizing the A.S.M.E. high pressure equipment.
Wind Tunnel Pressure Distribution Tests on a Series of Biplane Wing Models Part I: Effects of Changes in Stagger and Gap
This report is on the changes in forces on each wing of a biplane cellule when either the stagger or the gap is varied. Since each test was carried up to a 90 degree angle of attack, the results may be used in the study of stalled flight and of spinning as well as in the structural design of biplane wings.
Wind tunnel pressure distribution tests on a series of biplane wing models Part II: effects of changes in decalage, dihedral, sweepback and overhang
This preliminary report furnishes information on the changes in the forces on each wing of a biplane cellule when the decalage, dihedral, sweepback and overhang are separately varied. The data were obtained from pressure distribution tests made in the Atmospheric Wind Tunnel of the Langley Memorial Aeronautical Laboratory. Since each test was carried up to 90 degree angle of attack, the results may be used in the study of stalled flight and of spinning and in the structural design of biplane wings.
Wind tunnel pressure distribution tests on a series of biplane wing models Part III: effects of charges in various combinations of stagger, gap, sweepback, and decalage
A concept for the calculation of the vortex lift of sharp-edge delta wings is presented and compared with experimental data. The concept is based on an analogy between the vortex lift and the leading-edge suction associated with the potential flow about the leading edge. This concept, when combined with potential-flow theory modified to include the nonlinearities associated with the exact boundary condition and the loss of the lift component of the leading-edge suction, provides excellent prediction of the total lift for a wide range of delta wings up to angles of attack of 20 degrees or greater.
Wind Tunnel Pressure Distribution Tests on an Airfoil With Trailing Edge Flap
"This report deals with pressure distribution tests on an airfoil with a conventional trailing edge flap. These tests were conducted in the Atmospheric Wind Tunnel of the National Advisory Committee for Aeronautics. Maximum chord loadings were obtained with the flap displaced downward and with the airfoil at large angles of attack. Greater changes were produced in the normal force and in the center of pressure travel by up-flap than by an equal down-flap displacement" (p. 1).
Wind Tunnel Tests on a Model of a Monoplane Wing with Floating Ailerons
This report describes preliminary wind tunnel tests on a model of a monoplane wing equipped with wing tip floating ailerons. Lift and drag, as well as rolling and yawing moments, were measured.
Wind Tunnel Tests on Airfoil Boundary Control Using a Backward Opening Slot (1929)
"This report presents the results of an investigation to determine the effect of boundary layer control on the lift and drag of an airfoil equipped with a backward opening slot. Various slot locations, widths of opening, and pressures, were used. The tests were conducted in the Five-Foot Atmospheric Wind Tunnel of the Langley Memorial Aeronautical Laboratory" (p. 1).
Wind Tunnel Tests on an Airfoil Equipped With a Split Flap and a Slot
"The investigation described in this report is concerned with the changes in the aerodynamic characteristics of an airfoil which are produced by a gauze-covered suction slot, located near the leading edge, and connected by an air passage to a split flap at the trailing edge. The tests were conducted at the Langley Memorial Aeronautical Laboratory. At the larger values of lift coefficient where the action of the slot might be expected to be most effective, the pressure differences were such that the air flowed out of the slot rather than in through it, and in consequence, the maximum lift coefficient was decreased" (p. 1).
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