28 Matching Results

Search Results

The Aerodynamic Forces and Moments Exerted on a Spinning Model of the NY-1 Airplane as Measured by the Spinning Balance

Description: From Summary: "A preliminary investigation of the effects of changes in the elevator and rudder settings and of small changes in attitude upon the aerodynamic forces and moments exerted upon a spinning airplane was undertaken with the spinning balance in the 5-foot vertical tunnel of the National Advisory Committee for Aeronautics. The tests were made on a 1/12-scale model of the "NY-1" airplane. Data by which to fix the attitude, the radius of spin, and the rotational and air velocities were taken from recorded spins of the full-scale airplane."
Date: February 7, 1933
Creator: Bamber, M. J. & Zimmerman, C. H.
Partner: UNT Libraries Government Documents Department

Comparative flight performance with an NACA Roots supercharger and a turbocentrifugal supercharger

Description: This report presents the comparative flight results of a roots supercharger and a turbocentrifugal supercharger. The tests were conducted using a modified DH-4M2 airplane. The rate of climb and the high speed in level flight of the airplane were obtained for each supercharger from sea level to the ceiling. The unsupercharged performance with each supercharger mounted in place was also determined. The results of these tests show that the ceiling and rate of climb obtained were nearly the same for each supercharger, but that the high speed obtained with the turbocentrifugal was better than that obtained with the roots. The high-speed performance at 21,000 feet was 122 and 142 miles per hour for the roots and turbocentrifugal, respectively.
Date: February 25, 1930
Creator: Schey, Oscar W. & Young, Alfred W.
Partner: UNT Libraries Government Documents Department

The drag of airplane wheels, wheel fairings, and landing gears - 1

Description: This report presents the results of tests made in the 7-by 10-foot wind tunnel and in the 20-foot tunnel of the National Advisory Committee for Aeronautics to determine the drag of a number of airplane wheels, wheel fairings, and landing gears designed or selected for an airplane of 3,000 pounds gross weight. All tests were made on full-size models; those in the 7-by 10-foot tunnel were made at air speeds up to 80 miles per hour and those in the 20-foot tunnel were made at air speeds up to 100 miles per hour. Although most of the landing-gear tests were made in conjunction with a fuselage and at 0 degree pitch angle, some of the tests were made in conjunction with fuselage plus wings and a radial air-cooled engine and at pitch angles from -5 degrees to 6 degrees to obtain an indication of the general effect of these various items on landing-gear drag.
Date: February 9, 1934
Creator: Herrnstein, William H., Jr. & Biermann, David
Partner: UNT Libraries Government Documents Department

The Effect of Humidity on Engine Power at Altitude

Description: "From tests made in the altitude chamber of the Bureau of Standards, it was found that the effect of humidity on engine power is the same at altitudes up to 25,000 feet as at sea level. Earlier tests on automotive engines, made under sea-level conditions, showed that water vapor acts as an inert diluent, reducing engine power in proportion to the amount of vapor present. By combining the effects of atmospheric pressure, temperature, and humidity, it is shown that the indicated power obtainable from an engine is proportional to its mass rate of consumption of oxygen" (p. 523).
Date: February 24, 1932
Creator: Brooks, D. B. & Garlock, E. A.
Partner: UNT Libraries Government Documents Department

Effect of moderate air flow on the distribution of fuel sprays after injection cut-off

Description: "High-speed motion pictures were taken of fuel sprays with the NACA spray-photographic apparatus to study the distribution of the liquid fuel from the instant of injection cut-off until about 0.05 second later. The fuel was injected into a glass-walled chamber in which the air density was varied from 1 to 13 times atmospheric air density (0.0765 to 0.99 pound per cubic foot) and in which the air was at room temperature. The air in the chamber was set in motion by means of a fan, and was directed counter to the spray at velocities up to 27 feet per second" (p. 163).
Date: February 14, 1934
Creator: Rothrock, A. M. & Spencer, R. C.
Partner: UNT Libraries Government Documents Department

The effect of nozzle design and operating conditions on the atomization and distribution of fuel sprays

Description: The atomization and distribution characteristics of fuel sprays from automatic injection valves for compression-ignition engines were determined by catching the fuel drops on smoked-glass plates, and then measuring and counting the impressions made in the lampblack. The experiments were made in an air-tight chamber in which the air density was raised to values corresponding to engine conditions.
Date: February 19, 1932
Creator: Lee, Dana W.
Partner: UNT Libraries Government Documents Department

The effect of valve timing upon the performance of a supercharged engine at altitude and an unsupercharged engine at sea level

Description: This investigation was conducted to determine the comparative effects of valve timing on the performance of an unsupercharged engine at sea level and a supercharged engine at altitude. The tests were conducted on the NACA universal test engine. The timing of the four valve events was varied over a wide range; the engine speeds were varied between 1,050 and 1,500 r.p.m.; the compression ratios were varied between 4.35:1 and 7.35:1. The conditions of exhaust pressure and carburetor pressure of a supercharged engine were simulated for altitudes between 0 and 18,000 feet. The results show that optimum valve timing for a supercharged engine at an altitude of 18,000 feet differs slightly from that for an unsupercharged engine at sea level. A small increase in power is obtained by using the optimum timing for 18,000 feet for altitudes above 5,000 feet. The timing of the intake opening and exhaust closing becomes more critical as the compression ratio is increased.
Date: February 4, 1931
Creator: Schey, Oscar W. & Biermann, Arnold E.
Partner: UNT Libraries Government Documents Department

Experiments on the distribution of fuel in fuel sprays

Description: The distribution of fuel in sprays for compression-ignition engines was investigated by taking high-speed spark photographs of fuel sprays reproduced under a wide variety of conditions, and also by injecting them against pieces of plasticine. A photographic study was made of sprays injected into evacuated chambers, into the atmosphere, into compressed air, and into transparent liquids. Pairs of identical sprays were injected counter to each other and their behavior analyzed. Small high velocity air jets were directed normally to the axes of fuel sprays, with the result that the envelope of spray which usually obscures the core was blown aside, leaving the core exposed on one side. The results showed that the distribution of the fuel within the sprays was very uneven.
Date: February 13, 1932
Creator: Lee, Dana W.
Partner: UNT Libraries Government Documents Department

A Flight Investigation of the Spinning of the F4B-2 Biplane with Various Loads and Tail Surfaces

Description: "A flight investigation of the spinning of the F4B-2 single-seat fighter airplane was made for the purpose of finding modifications that would eliminate dangerous spin tendencies exhibited by this type of airplane in service. The effects on steady spins and on recoveries of changing the loading, enlarging the fin areas, changing the elevator plan form, and raising the horizontal surfaces, were determined" (p. 413).
Date: February 12, 1935
Creator: Scudder, N. F. & Seidman, Oscar
Partner: UNT Libraries Government Documents Department

The Forces and Moments Acting on Parts of the XN2Y-1 Airplane During Spins

Description: "The magnitudes of the yawing moments produced by various parts of an airplane during spins have previously been found to be of major importance in determining the nature of the spin. Discrepancies in resultant yawing moments determined from model and full-scale tests, however, have indicated the probable importance of scale effect on the model. In order to obtain data for a more detailed comparison between full-scale and model results, flight tests were made to determine the yawing moments contributed by various parts of an airplane in spins. The inertia moment was determined by the usual measurement of the spinning motion, and the aerodynamic yawing moments on the fuselage, fin, and rudder were determined by pressure-distribution measurements over these parts of the airplane" (p. 305).
Date: February 20, 1936
Creator: Scudder, N. F.
Partner: UNT Libraries Government Documents Department

Infrared Radiation From Explosions in a Spark-Ignition Engine

Description: This report presents the results of an investigation to determine the variations in intensity and spectral distribution of the radiant energy emitted by the flames during normal and knocking explosions in an engine. Radiation extending into the infrared was transmitted by a window of fluorite, placed either near the spark plug or over the detonation zone at opposite ends of the combustion chamber. Concave, surface-silvered mirrors focused the beam, first at the slit of a stroboscope which opened for about 2 degrees of crank angle at any desired point in the engine cycle, and then upon the target of a sensitive thermocouple for measuring radiation intensity.
Date: February 27, 1934
Creator: Marvin, Charles F., Jr.; Caldwell, Frank R. & Steele, Sydney
Partner: UNT Libraries Government Documents Department

Investigation of the Diaphragm-Type Pressure Cell

Description: "This report relates to various improvements in the process of manufacture of the NACA standard pressure cell. Like most pressure recording devices employing thin diaphragms, they would in general show considerable change in calibration with temperature and also some change of calibration with time or aging effect. The required diaphragm thickness and the desirable rate of mechanical magnification have been determined on the basis of several hundred tests" (p. 507).
Date: February 3, 1931
Creator: Theodorsen, Theodore
Partner: UNT Libraries Government Documents Department

A Method of Calculating the Ultimate Strength of Continuous Beams

Description: The purpose of this study was to investigate the strength of continuous beams after the elastic limit has been passed. As a result, a method of calculation, which is applicable to maximum load conditions, has been developed. The method is simpler than the methods now in use and it applies properly to conditions where the present methods fail to apply.
Date: February 1, 1930
Creator: Newlin, J. A. & Trayer, George W.
Partner: UNT Libraries Government Documents Department

The Pressure Distribution Over the Wings and Tail Surfaces of a PW-9 Pursuit Airplane in Flight

Description: This report presents the results of an investigation to determine (1) the magnitude and distribution of aerodynamic loads over the wings and tail surfaces of a pursuit-type airplane in the maneuvers likely to impose critical loads on the various subassemblies of the airplane structure, (2) To study the phenomenon of center of pressure movement and normal force coefficient variation in accelerated flight, and (3) to measure the normal accelerations at the center of gravity, wing-tip, and tail, in order to determine the nature of the inertia forces acting simultaneously with the critical aerodynamic loads. The results obtained throw light on a number of important questions involving structural design.
Date: February 3, 1930
Creator: Rhode, Richard V.
Partner: UNT Libraries Government Documents Department

Reduction of hinge moments of airplane control surfaces by tabs

Description: This report presents the results of an investigation conducted in the NACA 7 by 10-foot wind tunnel of control surfaces equipped with tabs for reducing the control forces or trimming the aircraft. Two sizes of ordinary ailerons with several sizes of attached and inset tabs were tested on a Clark y wing. Tabs were also tested in combination with auxiliary balances of the horn and paddle types, and with a frise balance aileron.
Date: February 5, 1935
Creator: Harris, Thomas A.
Partner: UNT Libraries Government Documents Department

Relative loading on biplane wings

Description: Recent improvements in stress analysis methods have made it necessary to revise and to extend the loading curves to cover all conditions of flight. This report is concerned with a study of existing biplane data by combining the experimental and theoretical data to derive a series of curves from which the lift curves of the individual wings of a biplane may be obtained.
Date: February 15, 1933
Creator: Diehl, Walter S.
Partner: UNT Libraries Government Documents Department

A simplified application of the method of operators to the calculation of disturbed motions of an airplane

Description: "A simplified treatment of the application of Heaviside's operational methods to problems of airplane dynamics is given. Certain graphical methods and logarithmic formulas that lessen the amount of computation involved are explained. The problem representing a gust disturbance or control manipulation is taken up and it is pointed out that in certain cases arbitrary control manipulations may be dealt with as though they imposed specific constraints on the airplane, thus avoiding the necessity of any integration" (p. 313).
Date: February 19, 1936
Creator: Jones, Robert T.
Partner: UNT Libraries Government Documents Department

Strength of Welded Joints in Tubular Members for Aircraft

Description: "The object of this investigation is to make available to the aircraft industry authoritative information on the strength, weight, and cost of a number of types of welded joints. This information will, also, assist the aeronautics branch in its work of licensing planes by providing data from which the strength of a given joint may be estimated. As very little material on the strength of aircraft welds has been published, it is believed that such tests made by a disinterested governmental laboratory should be of considerable value to the aircraft industry" (p. 323).
Date: February 6, 1930
Creator: Whittemore, H. L. & Brueggeman, W. C.
Partner: UNT Libraries Government Documents Department

Torsion Tests of Tubes

Description: "This report presents the results of tests of 63 chromium-molybdenum steel tubes and 102 17st aluminum-alloy tubes of various sizes and lengths made to study the dependence of the torsional strength on both the dimensions of the tube and the physical properties of the tube material. Three types of failure are found to be important for sizes of tubes frequently used in aircraft construction: (1) failure by plastic shear, in which the tube material reached its yield strength before the critical torque was reached; (2) failure by elastic two-lobe buckling, which depended only on the elastic properties of the tube material and the dimensions of the tube; and (3) failure by a combination of (1) and (2) that is, by buckling taking place after some yielding of the tube material" (p. 515).
Date: February 1937
Creator: Stang, Ambrose H.; Ramberg, Walter & Back, Goldie
Partner: UNT Libraries Government Documents Department

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 and it is found that, for thick elliptic cylinders, the two methods agree very well" (p. 245).
Date: February 11, 1938
Creator: Kaplan, Carl
Partner: UNT Libraries Government Documents Department

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 to within plus or minus 0.5 per cent" (p. 499).
Date: February 9, 1931
Creator: Wenzinger, Carl J. & Harris, Thomas A.
Partner: UNT Libraries Government Documents Department

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 characteristics for selected optimum arrangements were determined" (p. 1).
Date: February 12, 1938
Creator: Wenzinger, Carl J. & Harris, Thomas A.
Partner: UNT Libraries Government Documents Department

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 determined. A discussion is given of the relative merits of the various arrangement for certain selected criterions" (p. 665).
Date: February 24, 1939
Creator: Wenzinger, Carl J. & Harris, Thomas A.
Partner: UNT Libraries Government Documents Department