National Advisory Committee for Aeronautics (NACA) - 4,160 Matching Results

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Experimental Investigation to Determine the Relative Magnitude of Vertical and Horizontal Gusts in the Atmosphere

Description: Report presenting an investigation to obtain data on the vertical and horizontal gusts in the atmosphere by reworking accelerometers and airspeed records from past investigations of vertical gusts. The results indicate that the vertical and horizontal gusts are of about equal intensity in the atmosphere.
Date: July 1940
Creator: Donely, Philip
Partner: UNT Libraries Government Documents Department

Experimental Results With Airfoils Tested in the High-Speed Tunnel at Guidonia

Description: The results are presented of a triple series of tests using force measurements, pressure-distribution measurements, and air flow photographs on airfoil sections suitably selected so that comparison could be made between the experimental and theoretical results. The comparison with existing theory is followed by a discussion of the divergences found, and an attempt is made to find their explanation.
Date: July 1940
Creator: Ferri, Antonio
Partner: UNT Libraries Government Documents Department

Experiments on Ball and Roller Bearings Under Conditions of High Speed and Small Oil Supply

Description: This report describes a testing machine on which 35 millimeter bearings (bore) can be run at speeds of the order of 21,000 rpm, while the following factors are recorded: 1) oil circulation through bearing and oil temperature. 2) maximum temperature of outer bearing ring, 3) radial and axial load on bearing, 4) radial, axial, and angular clearance of bearing, 5) power consumption of bearing. The experiments show that the lubrication was most reliable and oil consumption lowest when the oil was introduced through a hole in the outer or inner ring of the bearing.
Date: July 1940
Creator: Getzlaff, Günter
Partner: UNT Libraries Government Documents Department

Heat Transfer Tests of a Steel Cylinder Barrel With Aluminum Fins With Improved Bonding Between Steel Barrel and Aluminum Base

Description: Report presenting testing of a steel cylinder barrel with aluminum fins in order to evaluate the effect of using preformed aluminum fins on a steel barrel or aluminum barrel. Results regarding the heat-transfer tests and physical tests are provided.
Date: July 1940
Creator: Ellerbrock, Herman H., Jr.
Partner: UNT Libraries Government Documents Department

New Equipment for Testing the Fatigue Strength of Riveted and Welded Joints

Description: "The mechanical and electrical construction of a new experimental instrument for fatigue testing riveted and welded joints is described. This experimental device has the advantage of being able to stress, even with comparatively low magnetic exciter force, structural components in alternate bending by resonance vibrations up to incipient fatigue failure (p .1)".
Date: July 1940
Creator: Müller, W
Partner: UNT Libraries Government Documents Department

Requirements for unit fuel-injection systems

Description: From Summary: "A unit injector was operated under various test conditions with a cam outline giving a high rate of plunger displacement. The rate of discharge of the unit injector followed the plunger displacement for the outwardly opening injection valve (open nozzle) except under conditions of high fuel pressures when the effect of fuel compressibility decreased the rate of discharge as the pressure increased. The rate of discharge for the inwardly opening injection valve (closed nozzle) did not directly follow the plunger displacement."
Date: July 1940
Creator: Marsh, Edred T.
Partner: UNT Libraries Government Documents Department

Spin Tests of a Low-Lying Monoplane in Flight and in the Free-Spinning Wind Tunnel

Description: "Comparative full-scale and model spin tests were made with a low-lying monoplane in order to extend the available information as to the utility of the free-spinning wind tunnel as an aid in predicting full-scale spin characteristics. For a given control disposition the model indicated steeper spins than were actually obtained with the airplane, the difference being most pronounced for spins with elevators up. Recovery characteristics for the model, on the whole, agreed with those for the airplane, but a disagreement was noted for the case of recovery with elevators held full up" (p. 1).
Date: July 1940
Creator: Seidman, Oscar & McAvoy, William H.
Partner: UNT Libraries Government Documents Department

A study of the air movement in two aircraft-engine cylinders

Description: From Summary: "Studies were made of the air movements in the NACA glass-cylinder apparatus using cylinder heads similar to those on the Wright R-1820-G engine and the Pratt & Whitney Wasp engine as modified by the Eclipse Aviation Corporation to use fuel-injection equipment. The air movements were made visible by mixing small feathers with the air; high-speed motion pictures were than taken of the feathers as they swirled about the inside the glass cylinder. The test engine speeds were 350, 500, and 1,000 r.p.m. Motion pictures were also taken of gasoline sprays injected into the cylinder during the intake stroke. The air flow produced by each cylinder head is described and some results of the velocity measurements of feathers are presented. The apparent time intervals required for vaporization of the gasoline sprays are also given."
Date: July 1940
Creator: Lee, Dana W.
Partner: UNT Libraries Government Documents Department

Propeller analysis from experimental data

Description: The operation of the propeller is analyzed by the use of the distribution of forces along the radius, combined with theoretical equations. The data were obtained in the NACA 20-foot wind tunnel on a 4-foot-diameter, two-blade propeller, operating in front of four body shapes, ranging from a small shaft to support the propeller to conventional NACA cowling. A method of estimating the axial and the rotational energy in the wake as a fractional part of the propeller power is given. A knowledge of the total thrust and torque is necessary for the estimation.
Date: July 19, 1940
Creator: Stickle, George W. & Crigler, John L.
Partner: UNT Libraries Government Documents Department

A high-speed motion-picture study of normal combustion, knock and preignition in a spark-ignition engines

Description: Combustion in a spark-ignition engine was investigated by means of the NACA high-speed motion-picture cameras. This camera is operated at a speed of 40,000 photographs a second and therefore makes possible the study of changes that take place in the intervals as short as 0.000025 second. When the motion pictures are projected at the normal speed of 16 frames a second, any rate of movement shown is slowed down 2500 times. Photographs are presented of normal combustion, of combustion from preignitions, and of knock both with and without preignition. The photographs of combustion show that knock may be preceded by a period of exothermic reaction in the end zone that persists for a time interval of as much as 0.0006 second. The knock takes place in 0.00005 second or less.
Date: July 24, 1940
Creator: Rothrock, A. M.; Spencer, R. C. & Miller, Cearcy D.
Partner: UNT Libraries Government Documents Department

Analysis of Cylinder-Pressure-Indicator Diagrams Showing Effects of Mixture Strength and Spark Timing

Description: "An investigation was made to determine the effect of mixture strength and of normal as well as optimum spark timing on the combustion, on the cylinder temperature, and on the performance characteristics of an engine. A single-cylinder test unit utilizing an air-cooled cylinder and a carburetor and operating with gasoline having an octane rating of 92 was used. The investigation covered a range of fuel-air ratios from 0.053 to 0.118. Indicator diagrams and engine-performance data were taken for each change in engine conditions" (p. 1).
Date: August 1940
Creator: Gerrish, Harold C. & Voss, Fred
Partner: UNT Libraries Government Documents Department

The Effects of Aerodynamic Heating on Ice Formations on Airplane Propellers

Description: An investigation has been made of the effect of aerodynamic heating on propeller-blade temperatures. The blade temperature rise resulting from aerodynamic heating was measured and the relation between the resulting blade temperatures and the outer limit of the iced-over region was examined. It was found that the outermost station at which ice formed on a propeller blade was determined by the blade temperature rise resulting from the aerodynamic heating at that point.
Date: August 1940
Creator: Rodert, Lewis A.
Partner: UNT Libraries Government Documents Department

Full-Scale Tests of 4- and 6-Blade, Single- and Dual-Rotating Propellers, Special Report

Description: Test of 10-foot diameter, 4- and 6-blade single- and dual-rotating propellers were conducted in the 20-foot propeller-research tunnel. The propellers were mounted at the front end of a streamline body incorporating spinners to house the hub portions. The effect of a symmetrical wing mounted in the slipstream was investigated. The blade angles investigated ranged from 20 degrees to 65 degrees; the latter setting corresponds to airplane speeds of over 500 miles per hour. The results indicate that dual-rotating propellers were from 0 to 6% more efficient than single-rotating ones; but when operating in the presence of a wing the gain was reduced about one-half. Other advantages of dual-rotating propellers were found to include greater power absorption and greater efficiency at the low V/nD operating range of high pitch propellers.
Date: August 1940
Creator: Biermann, David & Hartman, Edwin P.
Partner: UNT Libraries Government Documents Department

Heat-Transfer Tests of Two Steel Cylinder Barrels With Aluminum Fins Manufactured by Factory Production Method

Description: Report presenting testing of two engine cylinder barrels with aluminum fins. The primary purpose was to determine the heat-transfer coefficients and the excellence of the bonds between the aluminum fins and the aluminum base and between the aluminum base and the steel of the two barrels when manufactured by a large-volume production method.
Date: August 1940
Creator: Ellerbrock, Herman H., Jr.
Partner: UNT Libraries Government Documents Department

High-speed drag tests of several fuselage shapes in combination with a wing

Description: Drag testing was conducted in the high-speed wind tunnel of 23 conditions combining six streamline shapes and three conventional cowling-fuselage bodies. All of the models were tested in combination with a wing in order to include wing-fuselage interference effects. The critical speeds of combinations tested were, in general, determined by the wing-fuselage juncture.
Date: August 1940
Creator: Draley, Eugene C.
Partner: UNT Libraries Government Documents Department

Investigation of the boundary layer about a symmetrical airfoil in a wind tunnel of low turbulence

Description: Report presenting a series of boundary-layer surveys over the surface of an NACA 0012 airfoil at zero lift. Results regarding the pressure distribution, laminar boundary layer, transition, turbulent boundary layer, drag, and skin friction are provided.
Date: August 1940
Creator: von Doenhoff, Albert E.
Partner: UNT Libraries Government Documents Department

The maximum delivery pressure of single-stage radial superchargers for aircraft engines

Description: With the aid of simple considerations and test results, an attempt is made to clear up some obscure points that still exist. The considerations are restricted to those cases where it is in fact of advantage to"force" the large delivery heads required for high altitude and high supercharge with a single-stage supercharger.
Date: August 1940
Creator: von der Nüll, W.
Partner: UNT Libraries Government Documents Department

A Simple Approximation Method for Obtaining the Spanwise Lift Distribution

Description: The approximation method described makes possible lift-distribution computations in a few minutes. Comparison with an exact method shows satisfactory agreement. The method is of greater applicability than the exact method and includes also the important case of the wing with end plates.
Date: August 1940
Creator: Schrenk, O.
Partner: UNT Libraries Government Documents Department

Transient effects of the wing wake on the horizontal tail

Description: "An investigation was made of the effect of the wing wake on the lift of the horizontal tail surfaces. In the development of expressions for this effect, the growth of wing circulation and wing wake, the time interval represented by the tail length, and the development of lift by the rail were considered. The theory has been applied to a specific case to show the magnitude of the effect to be expected. It is shown that, for motions below a certain frequency, the development of lift by the tail may be represented by a simple lag function. The lag is, however, somewhat greater than that indicated by the rail length" (p. 1).
Date: August 1940
Creator: Jones, Robert T. & Fehlner, Leo F.
Partner: UNT Libraries Government Documents Department

Wind-tunnel investigation of effect of interference on lateral-stability characteristics of four NACA 23012 wings, an elliptical and a circular fuselage and vertical fins

Description: Report presents the results of a wind-tunnel investigation of the effect of wing-fuselage interference on lateral-stability characteristics made in the NACA 7 by 10-foot wind tunnel on four fuselages and two fins, representing high-wing, low-wing, and midwing monoplanes. The fuselages are of circular and elliptical cross section. The wings have rounded tips and, in plan form, one is rectangular and the three are tapered 3:1 with various amounts of sweep. The rate of change in the coefficients of rolling moment, yawing moment, and lateral force with angle of yaw is given in a form to show the increment caused by wing-fuselage interference for the model with no fin and the effect of wing-fuselage interference on fin effectiveness. Results for the fuselage-fin combination and the wing tested alone are also given.
Date: August 8, 1940
Creator: House, Rufus O. & Wallace, Arthur R.
Partner: UNT Libraries Government Documents Department

Wind-Tunnel Investigation of Spoiler, Deflector, and Slot Lateral-Control Devices on Wings With Full-Span Split and Slotted Flaps

Description: Report presents the results of an extensive investigation made in the NACA 7 by 10-foot wind tunnel of spoiler, deflector, and slot types of lateral-control device on wings with full-span split and slotted flaps. The static rolling and yawing moments were determined for all the devices tested, and the static hinge moments and the time response were determined for a few devices of each type.
Date: August 13, 1940
Creator: Wenzinger, Carl J. & Rogallo, Francis M.
Partner: UNT Libraries Government Documents Department

Investigation of the Characteristics of a High-Aspect-Ratio Wing in the Langley 8-Foot High-Speed Tunnel

Description: "An investigation of the characteristics of a wing with an aspect ratio of 9.0 and an NACA 65-210 airfoil section has been made at Mach number up to 0.925. The wing tested has a taper ratio of 2.5:1.0, no twist, dihedral, or sweepback, and 20-percent - chord 37.5-percent-semispan plain ailerons. The results showed that serious changes in the normal-force characteristics occurred when the Mach number was increased above 0.74 at angles of attack between 4 deg. and 10 deg. and above 0.80 at 0 deg. angle of attack" (p. 1).
Date: August 28, 1940
Creator: Whitcomb, Richard T.
Partner: UNT Libraries Government Documents Department