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Bending-Torsion Flutter Calculations Modified by Subsonic Compressibility Corrections

Description: From Summary: "A number of calculations of bending-torsion wing flutter are made at two Mach numbers, m=0 (incompressible case) and m=0.7, and results are compared. The air forces employed for the case of m=0.7 are based on Frazer's recalculation of Possio's results, which are derived on the assumption of small disturbances to the main flow. For ordinary wings of normal density and of low bending frequency in comparison with torsion frequency, the compressibility correction to the flutter speed… more
Date: December 18, 1945
Creator: Garrick, I. E.
Item Type: Refine your search to only Report
open access

Design Charts Relating to the Stalling of Tapered Wings

Description: An aid in airplane design, charts have been prepared to show the effects of wing taper, thickness ratio, and Reynolds number on the spanwise location of the initial stalling point. Means of improving poor stalling characteristics resulting from certain combinations of the variables have also been considered; additional figures illustrate the influence of camber increase to the wing tips, washout, central sharp leading edges, and wing-tip slots on the stalling characteristics. Data are included … more
Date: January 18, 1940
Creator: Soulé, H. A. & Anderson, R. F.
Item Type: Refine your search to only Report
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The Effect of Compressibility on Eight Full-Scale Propellers Operating in the Take-Off and Climbing Range

Description: "Tests were made of eight full-scale propellers of different shape at various tip speeds up to about 1,000 feet per second. The range of blade-angle settings investigated was from 10 degrees to 30 degrees at the 0.75 radius. The results indicate that a loss in propulsive efficiency occurred at tip speeds from 0.5 to 0.7 the velocity of sound for the take-off and climbing conditions" (p. 517).
Date: May 18, 1938
Creator: Biermann, David & Hartman, Edwin P.
Item Type: Refine your search to only Report
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Effect of exit-slot position and opening on the available cooling pressure for NACA nose-slot cowlings

Description: Report presents the results of an investigation of full-scale nose-slot cowlings conducted in the NACA 20-foot wind tunnel to furnish information on the pressure drop available for cooling. Engine conductances from 0 to 0.12 and exit-slot conductances from 0 to 0.30 were covered. Two basic nose shapes were tested to determine the effect of the radius of curvature of the nose contour; the nose shape with the smaller radius of curvature gave the higher pressure drop across the engine. The best ax… more
Date: January 18, 1939
Creator: Stickle, George W.; Naiman, Irven & Crigler, John L.
Item Type: Refine your search to only Report
open access

An experimental study of applied ground loads in landing

Description: Results are presented of an experimental investigation made of the applied ground loads and the coefficient of friction between the tire and the ground during the wheel spin-up process in impacts of a small landing gear under controlled conditions on a concrete landing strip in the Langley impact basin. The basic investigation included three major phases: impacts with forward speed at horizontal velocities up to approximately 86 feet per second, impacts with forward speed and reverse wheel rota… more
Date: August 18, 1955
Creator: Milwitzky, Benjamin; Lindquist, Dean C. & Potter, Dexter M.
Item Type: Refine your search to only Report
open access

Experimental Verification of the Theory of Wind-Tunnel Boundary Interference

Description: "The results of an experimental investigation on the boundary-correction factor are presented in this report. The values of the boundary-correction factor from the theory, which at the present time is virtually completed, are given in the report for all conventional types of tunnels. With the isolation of certain disturbing effects, the experimental boundary-correction factor was found to be in satisfactory agreement with the theoretically predicted values, thus verifying the soundness and suff… more
Date: May 18, 1933
Creator: Theodorsen, Theodore & Silverstein, Abe
Item Type: Refine your search to only Report
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A flight investigation of the spinning of the NY-1 airplane with varied mass distribution and other modifications, and an analysis based on wind-tunnel tests

Description: This report presents the results of an investigation of the spinning characteristics of NY-1 naval training biplane. The results of flight tests and an analysis based on wind-tunnel test data are given and compared. The primary purpose of the investigation was the determination in flight of the effect of changes in mass distribution along the longitudinal axis, without change of mass quantity or centroid. Other effects were also investigated, such as those due to wing loading, center-of-gravity… more
Date: June 18, 1932
Creator: Scudder, Nathan F.
Item Type: Refine your search to only Report
open access

Full-scale tests of NACA cowlings

Description: A comprehensive investigation has been carried on with full-scale models in the NACA 20-foot wind tunnel, the general purpose of which is to furnish information in regard to the physical functioning of the composite propeller-nacelle unit under all conditions of take-off, taxiing, and normal flight. This report deals exclusively with the cowling characteristics under condition of normal flight and includes the results of tests of numerous combinations of more than a dozen nose cowlings, about a… more
Date: May 18, 1936
Creator: Theodorsen, Theodore; Brevoort, M. J. & Stickle, George W.
Item Type: Refine your search to only Report
open access

Full Scale Tests of Wood Propellers on a VE-7 Airplane in the Propeller Research Tunnel

Description: "The investigation described in this report was made primarily to afford a comparison between propeller tests in the new propeller research tunnel and flight tests and small model tests on propellers. Three wood propellers which had been previously tested in flight on a VE-7 airplane, and of which models had also been tested in a wind tunnel, were tested again on a VE-7 airplane in the propeller research tunnel. The results of these tests are in fair agreement with those of the flight and model… more
Date: June 18, 1928
Creator: Weick, Fred E.
Item Type: Refine your search to only Report
open access

Full-Scale Wind-Tunnel Tests on Several Metal Propellers Having Different Blade Forms

Description: "This report gives the full-scale aerodynamic characteristics of five different aluminum alloy propellers having four different blade forms. They were tested on an open cockpit fuselage with a radial air-cooled engine having conventional cowling. The results show that (1) the differences in propulsive efficiency due to the differences in blade form were small; (2) the form with the thinnest airfoil sections had the highest efficiency; (3) it is advantageous as regards propulsive efficiency for … more
Date: March 18, 1929
Creator: Weick, Fred E.
Item Type: Refine your search to only Report
open access

Fundamental effects of aging on creep properties of solution-treated low-carbon N-155 alloy

Description: A method is developed whereby the fundamental mechanisms are investigated by which processing, heat treatment, and chemical composition control the properties of alloys at high temperatures. The method used metallographic examination -- both optical and electronic --studies of x-ray diffraction-line widths, intensities, and lattice parameters, and hardness surveys to evaluate fundamental structural conditions. Mechanical properties at high temperatures are then measured and correlated with thes… more
Date: January 18, 1949
Creator: Frey, D. N.; Freeman, J. W. & White, A. E.
Item Type: Refine your search to only Report
open access

Further experiments on the flow and heat transfer in a heated turbulent air jet

Description: "Measurements have been made of the mean-total-head and mean-temperature fields in a round turbulent jet with various initial temperatures. The results show that the jet spreads more rapidly as its density becomes lower than that of the receiving medium, even when the difference is not sufficiently great to cause dynamic-pressure function. Rough analytical considerations have given the same relative spread. The effective "turbulent Prandtl number" for a section of the fully developed jet was fo… more
Date: August 18, 1947
Creator: Corrsin, Stanley & Uberoi, Mahinder S.
Item Type: Refine your search to only Report
open access

Investigation of a nonlinear control system

Description: A discontinuous variation of coefficients of the differential equation describing the linear control system before nonlinear elements are added is studied in detail. The nonlinear feedback is applied to a second-order system. Simulation techniques are used to study performance of the nonlinear control system and to compare it with the linear system for a wide variety of inputs. A detailed quantitative study of the influence of relay delays and of a transport delay is presented.
Date: October 18, 1957
Creator: Flügge-Lotz, I.; Taylor, C. F. & Lindberg, H. E.
Item Type: Refine your search to only Report
open access

Lateral Control Required for Satisfactory Flying Qualities Based on Flight Tests of Numerous Airplanes

Description: Report presents the results of an analysis made of the aileron control characteristics of numerous airplanes tested in flight by the National Advisory Committee for Aeronautics. By the use of previously developed theory, the observed values of pb/2v for the various wing-aileron arrangements were examined to determine the effective section characteristics of the various aileron types.
Date: April 18, 1941
Creator: Gilruth, R. R. & Turner, W. N.
Item Type: Refine your search to only Report
open access

A Method of Computing the Transient Temperature of Thick Walls From Arbitrary Variation of Adiabatic-Wall Temperature and Heat-Transfer Coefficient

Description: "A method of calculating the temperature of thick walls has been developed in which the time series and the response to a unit triangle variation of surface temperature concepts are used, together with essentially standard formulas for transient temperature and heat flow into thick walls. The method can be used without knowledge of the mathematical tools of its development. The method is particularly suitable for determining the wall temperature in one-dimensional thermal problems in aeronautic… more
Date: June 18, 1957
Creator: Hill, P. R.
Item Type: Refine your search to only Report
open access

On a New Method for Calculating the Potential Flow Past a Body of Revolution

Description: "A new method is presented for obtaining the velocity potential of the flow about a body of revolution moving uniformly in the direction of its axis of symmetry in a fluid otherwise at rest. This method is based essentially on the fact that the form of the differential equation for the velocity potential is invariant with regard to conformal transformation of the meridian plane. By means of the conformal transformation of the meridian profile into a circle a system of orthogonal curvilinear coo… more
Date: May 18, 1942
Creator: Kaplan, Carl
Item Type: Refine your search to only Report
open access

On slender-body theory at transonic speeds

Description: The basic ideas of the slender-body approximation have been applied to the nonlinear transonic-flow equation for the velocity potential in order to obtain some of the essential features of slender-body theory at transonic speeds. The results of the investigation are presented from a unified point of view which demonstrates the similarity of slender-body solutions in the various Mach number ranges. The transonic area rule and some conditions concerning its validity follow from the analysis. (aut… more
Date: January 18, 1954
Creator: Harder, Keith C. & Klunker, E. B.
Item Type: Refine your search to only Report
open access

On the Theory of Oscillating Airfoils of Finite Span in Subsonic Compressible Flow

Description: "The problem of oscillating lifting surface of finite span in subsonic compressible flow is reduced to an integral equation. The kernel of the integral equation is approximated by a simpler expression, on the basis of the assumption of sufficiently large aspect ratio. With this approximation the double integral occurring in the formulation of the problem is reduced to two single integrals, one of which is taken over the chord and the other over the span of the lifting surface" (p. 969).
Date: May 18, 1948
Creator: Reissner, Eric
Item Type: Refine your search to only Report
open access

Origin and Prevention of Crash Fires in Turbojet Aircraft

Description: "The tendency for the jet engine rotor to continue to rotate after crash presents the probability that crash-spilled combustibles suspended in the air or puddled on the ground at the engine inlet may be sucked into the engine. Studies with jet engines operating on a test stand and full-scale crashes of turbojet-powered airplanes showed that combustibles drawn into the engine in this way ignite explosively within the engine. Experiment showed that the gas flow through the engine is too rapid to … more
Date: January 18, 1957
Creator: Pinkel, I. Irving; Weiss, Solomon; Preston, G. Merritt & Pesman, Gerard J.
Item Type: Refine your search to only Report
open access

A phenomenological relation between stress, strain rate, and temperature for metals at elevated temperatures

Description: Report presenting a phenomenological relation between stress, strain rate, and temperature to account for the behavior of polycrystalline metals above the equicohesive temperature. This is because the behavior of metals at elevated temperatures is constantly becoming a more important problem. The validity of the relation suggested in the equation appears to be accurate for 7075-T6 aluminum alloy.
Date: February 18, 1957
Creator: Stowell, Elbridge Z.
Item Type: Refine your search to only Report
open access

Relative loading on biplane wings of unequal chords

Description: It is shown that the lift distribution for a biplane with unequal chords may be calculated by the method developed in NACA Technical report no. 458 if corrections are made for the inequality in chord lengths. The method is applied to four cases in which the upper chord was greater than the lower and good agreement is obtained between observed and calculated lift coefficients.
Date: May 18, 1934
Creator: Diehl, Walter S.
Item Type: Refine your search to only Report
open access

The Similarity Rules for Second-Order Subsonic and Supersonic Flow

Description: "The similarity rules for linearized compressible flow theory (Gothert's rule and its supersonic counterpart) are extended to second order. It is shown that any second-order subsonic flow can be related to "nearly incompressible" flow past the same body, which can be calculated by the Janzen-Rayleigh method" (p. 925).
Date: October 18, 1956
Creator: Van Dyke, Milton D.
Item Type: Refine your search to only Report
open access

Tests of nacelle-propeller combinations in various positions with reference to wings. Part I : thick wing-N.A.C.A. cowled nacelle-tractor propeller

Description: This report gives the results in the 20-foot propeller research tunnel of the National Advisory Committee for Aeronautics on the interference drag and propulsive efficiency of a nacelle-propeller combination located in 21 positions with reference to a thick wing. The lift, drag, and propulsive efficiency were obtained at several angles of attack for each of the 21 locations. A net efficiency was derived for determining the over-all effectiveness of each nacelle location. Best results were obtai… more
Date: November 18, 1931
Creator: Wood, Donald H.
Item Type: Refine your search to only Report
open access

A wind-tunnel investigation of the aerodynamic characteristics of a full-scale supersonic-type three-blade propeller at Mach numbers to 0.96

Description: From Summary: "An investigation of the characteristics of a full-scale supersonic-type propeller has been made in the Langley 16-foot transonic tunnel with the 6000-horsepower propeller dynamometer. The tests covered a range of blade angles from 20.2 degrees to 60.2 degrees at forward Mach numbers up to 0.96. The results showed that envelope efficiency at an advance ratio of 2.8 decreased from 86 percent to 72 percent when the forward Mach number was increased from 0.70 to 0.96."
Date: May 18, 1953
Creator: Evans, Albert J. & Liner, George
Item Type: Refine your search to only Report
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