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High-Speed Tests of Conventional Radial-Engine Cowlings

Description: The drag characteristics of eight radial-engine cowlings have been determined over a wide speed range in the NACA 8-foot high-speed wind tunnel. The pressure distribution over all cowlings was measured, to and above the speed of the compressibility burble, as an aid in interpreting the force tests. One-fifth-scale models of radial-engine cowlings on a wing-nacelle combination were used in the tests.
Date: March 30, 1939
Creator: Robinson, Russell G. & Becker, John V.
Partner: UNT Libraries Government Documents Department
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Design of NACA Cowlings for Radial Air-Cooled Engines

Description: "The information on the propeller-cowling-nacelle combinations, presented in Technical Reports nos. 592, 593, and 596 and in Technical Note 620, is applied to the practical design of NACA cowlings. The main emphasis is placed on the method of obtaining the dimensions of the cowling; consequently, the physical functioning of each part of the cowling is treated very briefly. A practical method of designing cowlings and some examples are presented" (p. 383).
Date: March 5, 1938
Creator: Stickle, George W.
Partner: UNT Libraries Government Documents Department
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Wind-tunnel investigation of NACA 23012, 23021, and 23030 airfoils with various sizes of split flap

Description: Report presents the results of an investigation made in the NACA 7 by 10-foot wind tunnel of large-chord NACA and 23021, and 23030 airfoils with split flaps 10, 20, 30, and 40 percent of the wing chord to determine the section aerodynamic characteristics of the airfoils as affected by airfoil thickness, flap chord, and flap deflection. The complete section aerodynamic characteristics of all the combinations tested are given in the form of graphs of lift, drag, and pitching-moment coefficients, … more
Date: March 10, 1939
Creator: Wenzinger, Carl J. & Harris, Thomas A.
Partner: UNT Libraries Government Documents Department
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A Theoretical Study of the Moment on a Body in a Compressible Fluid

Description: "The extension to a compressible fluid of Lagally's theorem on the moment on a body in an incompressible fluid and Poggi's method of treating the flow of compressible fluids are employed for the determination of the effect of compressibility on the moment of an arbitrary body. Only the case of the two-dimensional subsonic flow of an ideal compressible fluid is considered. As examples of the application of the general theory, two well-known systems of profiles are treated; namely the elliptic pr… more
Date: March 24, 1939
Creator: Kaplan, Carl
Partner: UNT Libraries Government Documents Department
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Free-spinning wind-tunnel tests of a low-wing monoplane with systematic changes in wings and tails IV: effect of center-of-gravity location

Description: Eight wings and three tails, covering a wide range of aerodynamic characteristics, were independently ballasted so as to be interchangeable with no change in mass distribution. For each of the 24 resulting wing-tail combinations, observations were made of the steady spin for four control settings and of recoveries for five control manipulations. The results are presented in the form of charts comparing the spin characteristics. The tests are part of a general investigation being made in the NAC… more
Date: March 28, 1939
Creator: Seidman, Oscar & Neihouse, A. I.
Partner: UNT Libraries Government Documents Department
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On some reciprocal relations in the theory of nonstationary flows

Description: In the theory of nonstationary flows about airfoils, the "indicial lift" function ksub1(s) of Wagner and the "alternating lift" function c(k) of Theodorsen have fundamental significance. This paper reports on some interesting relations of the nature of Fourier transforms that exist between these functions. General problems in transient flows about airfoils may be given a unified broad treatment when these functions are employed. Certain approximate results also are reported which are of notable… more
Date: March 28, 1938
Creator: Garrick, I. E.
Partner: UNT Libraries Government Documents Department
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Alternating-current equipment for the measurement of fluctuations of air speed in turbulent flow

Description: From Summary: "Recent electrical and mechanical improvements have been made in the equipment developed at the National Bureau of Standards for measurement of fluctuations of air speed in turbulent flow. Data useful in the design of similar equipment are presented. The design of rectified alternating-current power supplies for such apparatus is treated briefly, and the effect of the power supplies on the performance of the equipment is discussed."
Date: March 1937
Creator: Mock, W. C., Jr.
Partner: UNT Libraries Government Documents Department
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Wind-tunnel investigation of wings with ordinary ailerons and full-span external-airfoil flaps

Description: Report presents an investigation carried out in the NACA 7- by 10-foot wind tunnel of an NACA 23012 airfoil equipped, first, with a full-span NACA 23012 external-airfoil flap having a chord 0.20 of the main airfoil chord and with a full-span aileron with a chord 0.12 of the main airfoil chord on the trailing edge of the main airfoil and equipped second, with a 0.30-chord full-span NACA 23012 external-airfoil flap and a 0.13-chord full-span aileron. The results are arranged in three groups, the … more
Date: March 12, 1937
Creator: Platt, Robert C. & Shortal, Joseph A.
Partner: UNT Libraries Government Documents Department
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The Crinkling Strength and the Bending Strength of Round Aircraft Tubing

Description: "The upper limit of the column strength of structural members composed of thin material is the maximum axial stress such members can carry when short enough to fail locally, by crinkling. This stress is a function of the mechanical properties of the material and of the geometrical shape of the cross section. The bending strength, as measured by the modulus of rupture, of structural members is also a function of these same variables. Tests were made of round tubes of chromium-molybdenum steel an… more
Date: March 28, 1938
Creator: Osgood, William R.
Partner: UNT Libraries Government Documents Department
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Pressure distribution over an NACA 23012 airfoil with a slotted and a plain flap

Description: Report presents the results of pressure-distribution of an NACA 23012 airfoil equipped with a slotted flap and with a plain flap conducted in the 7 by 10-foot wind tunnel. A test installation was used in which the 7-foot-span airfoil was mounted vertically between the upper and lower sides of the closed test section so that two-dimensional flow was approximated. The pressures were measured on the upper and lower surfaces at one chord section both on the main airfoil and on the flaps for several… more
Date: March 17, 1938
Creator: Wenzinger, Carl J. & Delano, James B.
Partner: UNT Libraries Government Documents Department
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Effect of nozzle design on fuel spray and flame formation in a high-speed compression-ignition engine

Description: "Fuel was injected from different type of injection nozzles into the combustion chamber of the NACA combustion apparatus, operated as a compression-ignition engine. High speed motion pictures were taken of the fuel sprays and combustion. Single-orifice nozzles of 0.008, 0.020, and 0.040 inch diameter, and multiorifice nozzles having 2, 6, and 16 orifices were tested. Nozzles having impinging jets and slit orifices were also included" (p. 327).
Date: March 19, 1936
Creator: Rothrock, A. M. & Waldron, C. D.
Partner: UNT Libraries Government Documents Department
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Air flow in the boundary layer near a plate

Description: From Summary: "The published data on the distribution of speed near a thin flat plate with sharp leading edge placed parallel to the flow (skin friction plate) are reviewed and the results of some additional measurements are described. The purpose of the experiments was to study the basic phenomena of boundary-layer flow under simple conditions."
Date: March 1936
Creator: Dryden, Hugh L.
Partner: UNT Libraries Government Documents Department
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Calculated and measured pressure distributions over the midspan section of the NACA 4412 airfoil

Description: Pressures were simultaneously measured in the variable-density tunnel at 54 orifices distributed over the midspan section of 5 by 30 inch rectangular model of the NACA 4412 airfoil at 17 angles of attack ranging from -20 degrees to 30 degrees at a Reynolds number of approximately 3,000,000. Accurate data were thus obtained for studying the deviations of the results of potential-flow theory from measured results. The results of the analysis and a discussion of the experimental technique are pres… more
Date: March 25, 1936
Creator: Pinkerton, Robert M.
Partner: UNT Libraries Government Documents Department
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Interference of Wing and Fuselage From Tests of 28 Combinations in the N.A.C.A. Variable-Density Tunnel

Description: Report presents the results of tests conducted on 28 wing-fuselage combinations made in the variable-density wind tunnel as a part of the wing-fuselage interference program being conducted therein and in addition to the 209 combinations previously reported in NACA-TR-540. These tests practically complete the study of combinations with a rectangular fuselage and continue the study of combinations with a round fuselage and a tapered wing.
Date: March 12, 1936
Creator: Sherman, Albert
Partner: UNT Libraries Government Documents Department
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A Turbulence Indicator Utilizing the Diffusion of Heat

Description: This report describes a method of determining the turbulence in wind tunnels. The effect of turbulence upon the diffusion of heat from a small electrically heated wire in an air stream was investigated. The turbulence of the stream was introduced by a series of geometrically similar screens placed one at a time across the upstream section of the tunnel. With the wire set at various distances from the screens, curves of temperature distribution were obtained by traversing the heated wake at a di… more
Date: March 8, 1935
Creator: Schubauer, G. B.
Partner: UNT Libraries Government Documents Department
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Characteristics of the NACA 23012 airfoil from tests in the full-scale and variable-density tunnels

Description: "This report gives the results of tests in the NACA full-scale and variable-density tunnels of a new wing section, the NACA 23012, which is one of the more promising of an extended series of related airfoils recently developed. The tests were made at several values of the Reynolds number between 1,000,000 and 8,000,000. The new airfoil develops a reasonably high maximum lift and a low profile drag, which results in an unusually high value of the speed-range index. In addition, the pitching-mome… more
Date: March 1, 1935
Creator: Jacobs, Eastman N. & Clay, William C.
Partner: UNT Libraries Government Documents Department
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Interference of wing and fuselage from tests of 209 combinations in the NACA variable-density tunnel

Description: This report presents the results of tests of 209 simple wing-fuselage combinations made in the NACA variable-density wind tunnel to provide information regarding the effects of aerodynamic interference between wings and fuselages at a large value of Reynolds number.
Date: March 8, 1935
Creator: Jacobs, Eastman N. & Ward, Kenneth E.
Partner: UNT Libraries Government Documents Department
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The N.A.C.A. Full-Scale Wind Tunnel

Description: This report gives a complete description of the full-scale wind tunnel of the National Advisory Committee for Aeronautics.
Date: March 13, 1933
Creator: DeFrance, Smith J.
Partner: UNT Libraries Government Documents Department
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The N.A.C.A. High-Speed Wind Tunnel and Tests of Six Propeller Sections

Description: "This report gives a description of the high-speed wind tunnel of the National Advisory Committee for Aeronautics. The operation of the tunnel is also described and the method of presenting the data is given. An account of an investigation of the aerodynamic properties of six propeller sections is included" (p. 399).
Date: March 28, 1933
Creator: Stack, John
Partner: UNT Libraries Government Documents Department
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The Weathering of Aluminum Alloy Sheet Materials Used in Aircraft

Description: This report presents the results of an investigation of the corrosion of aluminum alloy sheet materials used in aircraft. It has for its purpose to study the causes of corrosion embrittlement in duralumin-type alloys and the development of methods for its elimination. The report contains results, obtained in an extensive series of weather-exposure tests, which reveal the extent to which the resistance of the materials to corrosion was affected by variable factors in their heat treatment and by … more
Date: March 23, 1934
Creator: Mutchler, Willard
Partner: UNT Libraries Government Documents Department
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Temperature coefficient of the modulus of rigidity of aircraft instrument diaphragm and spring materials

Description: Experimental data are presented on the variation of the modulus of rigidity in the temperature range -20 to +50 degrees C. of a number of metals which are of possible use for elastic elements for aircraft and other instruments. The methods of the torsional pendulum was used to determine the modulus of rigidity and its temperature coefficient for aluminum, duralumin, monel metal, brass, phosphor bronze, coin silver, nickel silver, three high carbon steels, and three alloy steels. It was observed… more
Date: March 7, 1930
Creator: Brombacher, W. G. & Melton, E. R.
Partner: UNT Libraries Government Documents Department
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An Extended Theory of Thin Airfoils and Its Application to the Biplane Problem

Description: "The report presents a new treatment, due essentially to von Karman, of the problem of the thin airfoil. The standard formulae for the angle of zero lift and zero moment are first developed and the analysis is then extended to give the effect of disturbing or interference velocities, corresponding to an arbitrary potential flow, which are superimposed on a normal rectilinear flow over the airfoil. An approximate method is presented for obtaining the velocities induced by a 2-dimensional airfoil… more
Date: March 15, 1930
Creator: Millikan, Clark B.
Partner: UNT Libraries Government Documents Department
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Span-load distribution as a factor in stability in roll

Description: "This report gives the results of pressure-distribution tests made to study the effects on lateral stability of changing the span-load distribution on a rectangular monoplane wing model of fairly thick section. Three methods of changing the distribution were employed: variation in profile along the span to a thin symmetrical section at the tip, twist from +5 degrees to -15 degrees at the tip, and sweepback from +20 degrees to -20 degrees. The tests were conducted in a 5-foot closed-throat atmos… more
Date: March 4, 1931
Creator: Knight, Montgomery & Noyes, Richard W.
Partner: UNT Libraries Government Documents Department
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A New Principle of Sound Frequency Analysis

Description: "In connection with the study of aircraft and propeller noises, the National Advisory Committee for Aeronautics has developed an instrument for sound-frequency analysis which differs fundamentally from previous types, and which, owing to its simplicity of principle, construction, and operation, has proved to be of value in this investigation. The method is based on the well-known fact that the Ohmic loss in an electrical resistance is equal to the sum of the losses of the harmonic components of… more
Date: March 23, 1931
Creator: Theodorsen, Theodore
Partner: UNT Libraries Government Documents Department
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