National Advisory Committee for Aeronautics (NACA) - 1,346 Matching Results

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Engine Knock and Combustion Chamber Form

Description: The present report is confined to the effect of the combustion chamber shape on engine knock from three angles, namely: 1) The uniformity of flame-front movement as affected by chamber design and position of the spark plug; 2) The speed of advance of the flame as affected by turbulence and vibrations; 3) The reaction processes in the residual charge as affected by the walls.
Date: October 1939
Creator: Zinner, Karl
Partner: UNT Libraries Government Documents Department
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Experimental and Analytical Investigation of a Monocoque Wing Model Loaded in Bending

Description: "Bending tests with transverse loads and with pure bending were undertaken on a double-web monocoque wing model in order to establish the relation between the state of stress and the results from the elementary bending theory. The longitudinal stresses in the stiffeners were measured with tensiometers and the shear stresses in the sheet were calculated from them. The measurements were made at both moderate loads with no buckles in the covering and at loads with which the critical stress in the … more
Date: October 1939
Creator: Schapitz, E.; Feller, H. & Köller, H.
Partner: UNT Libraries Government Documents Department
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Experimental Study of Torsional Column Failure

Description: "Thirty-three 24ST aluminum-alloy 2- by 2- by 0.10-inch channels, with lengths ranging from 10 to 90 inches were tested at Stanford University in compression to obtain an experimental verification of the theoretical formulas for torsional failure developed by Eugene E. Lundquist of the N.A.C.A. The observed critical loads and twist-axis locations were sufficiently close to the values obtained from the formulas to establish the substantial validity of the latter. The differences between observed… more
Date: October 1939
Creator: Niles, Alfred S.
Partner: UNT Libraries Government Documents Department
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Ground-cooling and flight tests of an airplane equipped with a nose-blower engine cowling

Description: Report presenting flight and ground-cooling tests with a Northrop A-17A attack airplane to determine the merits of a nose-blower engine cowling designed and built at the NACA laboratory. The main objective was to determine the cooling characteristics of the nose blower, especially for ground and low-speed operation. Results regarding the cooling properties, engine pressure drop, and maximum speed and drag are provided.
Date: October 1939
Creator: Turner, L. I., Jr.
Partner: UNT Libraries Government Documents Department
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Increase of the Specific Load Under Tension, Compression, and Buckling of Welded Steel Tubes in Airplane Construction by Suitable Treatment of Structural Steel and by Proper Design

Description: Report presenting some considerations and test results that may lead to higher tension, compression, and buckling stresses than is possible with the welded-steel-tube struts of the usual familiar construction. The new construction method makes possible a considerably better material utilization and hence a saving in weight.
Date: October 1939
Creator: Müller, J.
Partner: UNT Libraries Government Documents Department
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Tandem Air Propellers - 2

Description: "Tests of three-blade, adjustable-pitch counterrotating tandem model propellers, adjusted to absorb equal power at maximum efficiency of the combination, were made at Stanford University. The aerodynamic characteristics, for blade-angle settings of 15, 25, 35, 45, 55, and 65 degrees at 0.75R of the forward propeller and for diameters spacings of 8-1/2, 15 and 30% were compared with those of three-blade and six-blade propellers of the same blade form. It was found that, in order to realize the c… more
Date: October 1939
Creator: Lesley, E. P.
Partner: UNT Libraries Government Documents Department
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Tests in the gust tunnel of a model of the XBM-1 airplane

Description: Report presenting testing of a dynamically scaled model of a Navy XBM-1 biplane in the gust tunnel to provide data for use in determining the structure of atmospheric gusts from measurements of the motions of the full-scale airplane in rough air. Records for two flights for several gradients were evaluated to give histories of events during passage through the gust.
Date: October 1939
Creator: Donely, Philip & Shufflebarger, C. C.
Partner: UNT Libraries Government Documents Department
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Flame Speeds and Energy Considerations for Explosions in a Spherical Bomb

Description: "Simultaneous measurements were made of the speed of flame and the rise in pressure during explosions of mixtures of carbon monoxide, normal heptane, iso-octane, and benzene in a 10-inch spherical bomb with central ignition. From these records, fundamental properties of the explosive mixtures, which are independent of the apparatus, were computed. The transformation velocity, or speed at which flame advances into and transforms the explosive mixture, increases with both the temperature and the … more
Date: September 28, 1939
Creator: Fiock, Ernest F.; Marvin, Charles F., Jr.; Caldwell, Frank R. & Roeder, Carl H.
Partner: UNT Libraries Government Documents Department
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Combined Beam-Column Stresses of Aluminum-Alloy Channel Sections

Description: The results of a research program to obtain design data on the strength of open-channel aluminum-alloy sections subjected to combined column and beam action. The results of the tests of about 70 specimens were graphed for stresses due to axial load and stresses due to bending loading as functions of length to radius of gyration of the specimens. From these graphs a design chart was derived that is suitable for ready use.
Date: September 1939
Creator: Gottlieb, R.; Thompson, T. M. & Witt, E. C.
Partner: UNT Libraries Government Documents Department
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Dynamic Stability of a Helicopter With Hinged Rotor Blades

Description: "The present report is a study of the dynamic stability of a helicopter with hinged rotor blades under hovering conditions. While in this case perfect stability can in general not be obtained it is possible by means of design features to prolong the period of the spontaneous oscillations of the helicopter and reduce their amplification, and so approximately assure neutral equilibrium. The possibility of controlled stability of a helicopter fitted with hinged blades is proved by the successful f… more
Date: September 1939
Creator: Hohenemser, K.
Partner: UNT Libraries Government Documents Department
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An Electrical-Type Indicating Fuel Flowmeter

Description: "An electrical-type meter has been developed for measuring mass rates of flow of gasoline or other nonconducting fluids. Its temperature dependence is small over a large range and it has no known vibrational or viscosity errors. The maximum temperature rise is less than 5 C. The rates of flow, measurable within 1% with the present instrument, are approximately 100 to 1,000 or more pounds of gasoline per hour when a potentiometer is used, or 100 to 300 pounds per hour when a deflection-type mete… more
Date: September 1939
Creator: Tozier, Robert E.
Partner: UNT Libraries Government Documents Department
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A flight investigation of the distribution of ice-inhibiting fluids on a propeller blade

Description: Report presenting an investigation of the flow of ice-inhibiting fluids over the blade surfaces of a 12.5-foot-daimeter propeller in flight by discharging dyed fluids at various stations along the leading edges of the blades. The effects on the distribution of varying the fluid composition, the blade-surface roughness, and the orifice design were also observed.
Date: September 1939
Creator: Rodert, Lewis A.
Partner: UNT Libraries Government Documents Department
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An instrument for estimating tautness of doped fabrics on aircraft

Description: Technical note presenting the design and use of a spring-loaded tautness meter that can be used in both horizontal and vertical positions to compare the tautness of various panels. Results of tests made on the fabric coverings of various airplanes are reported and discussed.
Date: September 1939
Creator: Kline, Gordon M. & Schiefer, Herbert F.
Partner: UNT Libraries Government Documents Department
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Intercooler Design for Aircraft, Special Report

Description: "When an airplane is operating at high altitude, it is necessary to use a supercharger to maintain ground pressure at the carburetor inlet. This maintenance and high intake-manifold pressure tends to keep the power output of the engine at ground-level value. The air, being compressed by the supercharger, however, is heated by adiabatic compression and friction to a temperature that seriously affect the performance of the engine. It is thus necessary to use an intercooler to reduce the temperatu… more
Date: September 1939
Creator: Brevoort, M. J.; Joyner, U. T. & Leifer, M.
Partner: UNT Libraries Government Documents Department
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Knocking in the Otto-Cycle Engine

Description: Engine knock is, as is known, preceded by normal burning of the first part of the charge, and only the part burned last (residual charge), knocks. The aim of the present measurements was, first, to reexamine the combustion form in this residual charge, because of the absence of uniform and frequently contradictory results in the very extensive literature on the subject. On top of that, an attempt was to be made to gain a deeper insight into the mechanism accompanying the combustion process, by … more
Date: September 1939
Creator: Weinhart, H.
Partner: UNT Libraries Government Documents Department
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Measurements on a Low-Wing Model in the Rotating Jet and Comparison With Flight Measurements

Description: The present report deals with six-component measurements in the small tunnel of the DVL on a model of the BFW-M 27b(sub 1), which were made to determine the effect of rolling and yawing on the air forces and moments. The wind was given a spiral motion by means of a rotating screen, the model being suspended in the conventional manner. The lack of accuracy in the measurement of the rolling-yawing moments was very noticeable.
Date: September 1939
Creator: Bader, W.
Partner: UNT Libraries Government Documents Department
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Tests of Several Model Nacelle-Propeller Arrangements in Front of a Wing

Description: Report presenting an investigation in the 20-foot wind tunnel to determine the drag, propulsive and net efficiencies, and cooling characteristics of several scale-model arrangements of air-cooled radial-engine nacelles and present-day propellers in front of an 18-percent-thick, 5-by-15-foot airfoil. Two 3-blade propellers with differing diameters were tested in conjunction with a 12-inch-diameter nacelle in three positions in front of the wing and with a 16-inch-diameter nacelle in six position… more
Date: September 1939
Creator: McHugh, James G.
Partner: UNT Libraries Government Documents Department
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Tests of Several Model Nacelle-Propeller Arrangements in Front of a Wing

Description: "An investigation was conducted in the N.A.C.A. 20-foot wind tunnel to determine the drag, the propulsive and net efficiencies, and the cooling characteristics of several scale-model arrangements of air-cooled radial-engine nacelles and present-day propellers in front of an 18- percent-thick, 5- by 15-foot airfoil. This report deals with an investigation of wing-nacelle arrangements simulating the geometric proportions of airplanes in the 40,000- to 70,000- pound weight classification and havin… more
Date: September 1939
Creator: McHugh, James G.
Partner: UNT Libraries Government Documents Department
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The Theory of Contra-Vanes Applied to the Propeller

Description: "The optimum circulation distribution and hence the maximum theoretical thrust obtainable for contra-vanes fitted behind propellers is markedly dependent on the number of guide vanes. The outer portion of the vanes, even if projecting considerably beyond the edge of the propeller slipstream, still contribute appreciably to this theoretical gain of thrust. But, owing to the always existing friction of the vanes, the limit of the optimum vane length lies at relatively small diameters" (p. 1).
Date: September 1939
Creator: Betz, Albert
Partner: UNT Libraries Government Documents Department
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Two-Stroke-Cycle Engines With Unsymmetrical Control Diagram (Supercharged Engines)

Description: As no investigation of supercharging in 2-stroke-cycle engines has been published up to the present, this article is an attempt in that direction, with a view to establishing the mathematical principles and the constructive rules for the design of such engines.
Date: September 1939
Creator: Zeman, J.
Partner: UNT Libraries Government Documents Department
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Wind-Tunnel Investigation of an N.A.C.A. 23021 Airfoil With Two Arrangements of a 40-Percent-Chord Slotted Flap

Description: Note presenting an investigation in the 7- by 10-foot wind tunnel of an NACA 23021 airfoil with two arrangements of a 40-percent-chord slotted flap. The effect of slot shape, flap position, and flap deflection on the section aerodynamic characteristics was determined. Results regarding coefficients, precision, plain airfoils, and slotted-flap arrangements are provided.
Date: September 1939
Creator: Duschik, Frank
Partner: UNT Libraries Government Documents Department
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Wind-Tunnel Investigation of Effect of Yawing on Lateral-Stability Characteristics 2: Rectangular N.A.C.A. 23012 Wing with a Circular Fuselage and a Fin

Description: Note presenting testing of an N.A.C.A. 23012 rectangular wing with rounded tips in combination with a fuselage of circular cross section at several angles of yaw in the NACA 7- by 10-foot wind tunnel. The model was tested as a high-wing, a midwing, and a low-wing monoplane; for each wing location, tests were made with two amounts of dihedral and with partial-span split flaps. Results regarding the wing and fuselage, fin and fuselage, and wing, fuselage, and fin are provided.
Date: September 1939
Creator: Bamber, M. J. & House, R. O.
Partner: UNT Libraries Government Documents Department
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Longitudinal Stability and Control With Special Reference to Slipstream Effects

Description: Report presents the results of a study of data obtained in the NACA full-scale wind tunnel concerning the effects of interference and of propeller operation on longitudinal stability and control. The data include pitching moments for various power conditions for airplanes with tails removed and with tails set at various stabilizer and elevator angles. A number of surveys of the dynamic pressure and the flow direction in the region of the horizontal tail surface are also included.
Date: August 24, 1939
Creator: Katzoff, S.
Partner: UNT Libraries Government Documents Department
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