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Effect of Interaction on Landing-Gear Behavior and Dynamic Loads in a Flexible Airplane Structure

Description: "The effects of interaction between a landing gear and a flexible airplane structure on the behavior of the landing gear and the loads in the structure have been studied by treating the equations of motion of the airplane and the landing gear as a coupled system. The landing gear is considered to have nonlinear characteristics typical of conventional gears, namely, velocity-squared damping, polytropic air-compression springing, and exponential tire force-deflection characteristics. For the case… more
Date: May 5, 1955
Creator: Cook, Francis E. & Milwitzky, Benjamin
Item Type: Refine your search to only Report
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Theoretical analysis of incompressible flow through a radial-inlet centrifugal impeller at various weight flows

Description: A method for the solution of the incompressible nonviscous flow through a centrifugal impeller, including the inlet region, is presented. Several numerical solutions are obtained for four weight flows through an impeller at one operating speed. These solutions are refined in the leading-edge region. The results are presented in a series of figures showing streamlines and relative velocity contours. A comparison is made with the results obtained by using a rapid approximate method of analysis.
Date: March 4, 1955
Creator: Kramer, James J.; Prian, Vasily D. & Wu, Chung-Hua
Item Type: Refine your search to only Report
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Theoretical investigation of flutter of two-dimensional flat panels with one surface exposed to supersonic potential flow

Description: From Summary: "A Rayleigh type analysis involving chosen modes of the panel as degrees of freedom is used to treat the flutter of a two-dimensional flat panel supported at its leading and trailing edges and subjected to a middle-plane tensile force. The panel has a supersonic stream passing over its upper surface and still air below. The aerodynamic forces due to the supersonic stream are obtained from the theory for linearized two-dimensional unsteady flow and the forces due to the still air a… more
Date: 1956
Creator: Nelson, Herbert C. & Cunningham, Herbert J.
Item Type: Refine your search to only Report
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A special method for finding body distortions that reduce the wave drag of wing and body combinations at supersonic speeds

Description: For a given wing and supersonic Mach number, the problem of shaping an adjoining fuselage so that the combination will have a low wave drag is considered. Only fuselages that can be simulated by singularities (multipoles) distributed along the body axis are studied. However, the optimum variations of such singularities are completely specified in terms of the given wing geometry. An application is made to an elliptic wing having a biconvex section, a thickness-chord ratio equal to 0.05 at the r… more
Date: May 16, 1956
Creator: Lomax, Harvard & Heaslet, Max A.
Item Type: Refine your search to only Report
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Extrapolation techniques applied to matrix methods in neutron diffusion problems

Description: "A general matrix method is developed for the solution of characteristic-value problems of the type arising in many physical applications. The scheme employed is essentially that of Gauss and Seidel with appropriate modifications needed to make it applicable to characteristic-value problems. An iterative procedure produces a sequence of estimates to the answer; and extrapolation techniques, based upon previous behavior of iterants, are utilized in speeding convergence. Theoretically sound limit… more
Date: May 12, 1955
Creator: McCready, Robert R.
Item Type: Refine your search to only Report
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Error in airspeed measurement due to the static-pressure field ahead of an airplane at transonic speeds

Description: The magnitude and variation of the static-pressure error for various distances ahead of sharp-nose bodies and open-nose air inlets and for a distance of 1 chord ahead of the wing tip of a swept wing are defined by a combination of experiment and theory. The mechanism of the error is discussed in some detail to show the contributing factors that make up the error. The information presented provides a useful means for choosing a proper location for measurement of static pressure for most purposes. more
Date: August 3, 1955
Creator: O'Bryan, Thomas C.; Danforth, Edward C. B. & Johnston, J. Ford
Item Type: Refine your search to only Report
open access

An investigation of the effects of heat transfer on boundary-layer transition on a parabolic body of revolution (NACA RM-10) at a Mach number of 1.61

Description: Report presents the results of an investigation conducted to determine the effects of heat transfer on boundary-layer transition on a parabolic body of revolution (NACA rm-10 without fins) at Mach number of 1.61 and over a Reynolds number range from 2.5 x 10(6) to 35 x 10(6). The maximum cooling of the model used in these tests corresponded to a temperature ratio (ratio of model-surface temperature to free-stream temperature) of 1.12, a value somewhat higher than the theoretical value required … more
Date: February 16, 1953
Creator: Czarnecki, K. R. & Sinclair, Archibald R.
Item Type: Refine your search to only Report
open access

Free-Stream Boundaries of Turbulent Flows

Description: Report presents the results of an experimental and theoretical study made of the instantaneously sharp and irregular front which is always found to separate turbulent fluid from contiguous "nonturbulent" fluid at a free-stream boundary. This distinct demarcation is known to give an intermittent character to hot-wire signals in the boundary zone. The overall behavior of the front is described statistically in terms of its wrinkle-amplitude growth and its lateral propagation relative to the fluid… more
Date: 1955
Creator: Corrsin, Stanley & Kistler, Alan L.
Item Type: Refine your search to only Report
open access

Analysis and Calculation by Integral Methods of Laminar Compressible Boundary-Layer With Heat Transfer and With and Without Pressure Gradient

Description: From Introduction: "The purpose of the present report is to present a comprehensive summary of theoretical investigations of comprehensible laminar boundary layers which have been carried out since 1949 at the Polytechnic Institute of Brooklyn under the sponsorship and with the financial assistance of the National Advisory Committee for Aeronautics. The results of these investigations are contained primarily in references 1 to 7."
Date: April 12, 1955
Creator: Morduchow, Morris
Item Type: Refine your search to only Report
open access

The hydrodynamic characteristics of modified rectangular flat plates having aspect ratios of 1.00, 0.25, and 0.125 and operating near a free water surface

Description: Report presents the results of an investigation conducted to determine the hydrodynamic forces and moments acting on modified rectangular flat plates with aspect ratios of 1.00, 0.25, and 0.125 mounted on a single strut and operating at several depths of submersion. A simple method has been developed by modification of Falkner's vortex-lattice theory which enables the prediction of the lift characteristics in unseparated flow at large depths. This method shows good agreement with experimental d… more
Date: January 19, 1954
Creator: Wadlin, Kenneth L.; Ramsen, John A. & Vaughan, Victor L., Jr.
Item Type: Refine your search to only Report
open access

Characteristics of Turbulence in Boundary Layer with Zero Pressure Gradient

Description: "The results of an experimental investigation of a turbulent boundary layer with zero pressure gradient are presented. Measurements with the hot-wire anemometer were made of turbulent energy and turbulent shear stress, probability density and flattening factor of u-fluctuation (fluctuation in x-direction), spectra of turbulent energy and shear stress, and turbulent dissipation. The importance of the region near the wall and the inadequacy of the concept of local isotropy are demonstrated" (p. 1… more
Date: 1955
Creator: Klebanoff, P. S.
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

The dynamic-response characteristics of a 35 degree swept-wing airplane as determined from flight measurements

Description: From Summary: "The longitudinal and lateral-directional dynamic-response characteristics of a 35 degree swept-wing fighter-type airplane determined from flight measurements are presented and compared with predictions based on theoretical studies and wind-tunnel data. Flights were made at an altitude of 35,000 feet covering the Mach number range of 0.50 to 1.04. A limited amount of lateral-directional data were also obtained at 10,000 feet. The flight consisted essentially of recording transient… more
Date: September 17, 1952
Creator: Triplett, William C.; Brown, Stuart C. & Smith, G. Allan
Item Type: Refine your search to only Report
open access

Stress Analysis of Circular Semimonocoque Cylinders With Cutouts

Description: "A method is presented for analyzing the stresses about cutouts in circular semimonocoque cylinders with flexible rings. The method involves the use of so-called perturbation stress distributions which are superposed on the stress distribution that would exist in the structure with no cutout in such a way as to give the effects of a cutout. The method can be used for any loading case for which the structure without the cutout can be analyzed and is sufficiently versatile to account for stringer… more
Date: 1955
Creator: McComb, Harvey G., Jr.
Item Type: Refine your search to only Report
open access

A correlation by means of transonic similarity rules of experimentally determined characteristics of a series of symmetrical and cambered wings of rectangular plan form

Description: Transonic similarity rules are applied to the correlation of experimental data for a series of related rectangular wings of varying aspect ratio, thickness, and camber. The data correlation is presented in two parts: the first part presents the correlation for a series of 22 wings having symmetrical NACA 63a-series sections; the second part is concerned with a study of one type of camber by correlation of the data for a series of 18 cambered wings having NACA 63a2xx and 63a4xx sections.
Date: December 17, 1951
Creator: McDevitt, John B.
Item Type: Refine your search to only Report
open access

Friction, wear, and surface damage of metals as affected by solid surface films

Description: "As predicted by friction theory, experiments showed that friction and surface damage of metals can be reduced by solid surface films. The ability of materials to form surface films that prevent welding was a very important factor in wear of dry and boundary lubricated surfaces. Films of graphitic carbon on cast irons, NiO on nickel alloys, and FeO and Fe(sub 3)O(sub 4) on ferrous materials were found to be beneficial. Abrasive films such as Fe(sub 2)O(sub 3) or MoO(sub 3) were definitely detri… more
Date: February 10, 1955
Creator: Bisson, Edmond E.; Johnson, Robert L.; Swikert, Max A. & Godfrey, Douglas
Item Type: Refine your search to only Report
open access

An analysis of the stability and ultimate compressive strength of short sheet-stringer panels with special reference to the influence of the riveted connection between sheet and stringer

Description: A method of strength analysis of short sheet-stringer panels subjected to compression is presented which takes into account the effect that the riveted attachments between the plate and the stiffeners have on the strength of panels. An analysis of experimental data shows that panel strength is highly influenced by rivet pitch, diameter, and location and that the degree of influence for a given riveting depends on the panel configuration and panel material.
Date: 1956
Creator: Semonian, Joseph W. & Peterson, James P.
Item Type: Refine your search to only Report
open access

Axially Symmetric Shapes With Minimum Wave Drag

Description: "The external wave drag of bodies of revolution moving at supersonic speeds can be expressed either in terms of the geometry of the body, or in terms of the body-simulating axial source distribution. For purposes of deriving optimum bodies under various given conditions, it is found that the second of the methods mentioned is the more tractable. By use of a quasi-cylindrical theory, that is, the boundary conditions are applied on the surface of a cylinder rather than on the body itself, the var… more
Date: November 22, 1954
Creator: Heaslet, Max A. & Fuller, Franklyn B.
Item Type: Refine your search to only Report
open access

On the Kernel function of the integral equation relating lift and downwash distributions of oscillating wings in supersonic flow

Description: From Summary: "This report treats the Kernel function of the integral equation that relates a known or prescribed downwash distribution to an unknown lift distribution for harmonically oscillating wings in supersonic flow. The treatment is essentially an extension to supersonic flow of the treatment given in NACA report 1234 for subsonic flow. For the supersonic case the Kernel function is derived by use of a suitable form of acoustic doublet potential which employs a cutoff or Heaviside unit f… more
Date: February 15, 1955
Creator: Watkins, Charles E. & Berman, Julian H.
Item Type: Refine your search to only Report
open access

A wind-tunnel test technique for measuring the dynamic rotary stability derivatives at subsonic and supersonic speeds

Description: "A method is described for measuring the dynamic stability derivatives of a model airplane in a wind tunnel. The characteristic features of this system are that single-degree-of-freedom oscillations were used to obtain combinations of rolling, yawing and pitching motions; that the oscillations were excited and controlled by velocity feedback which permitted operation under conditions unfavorable for more conventional types of oscillatory testing; and that data processing was greatly simplified … more
Date: September 20, 1954
Creator: Beam, Benjamin H.
Item Type: Refine your search to only Report
open access

Some possibilities of using gas mixtures other than air in aerodynamic research

Description: A study is made of the advantages that can be realized in compressible-flow research by employing a substitute heavy gas in place of air. The present report is based on the idea that by properly mixing a heavy monatomic gas with a suitable heavy polyatomic gas, it is possible to obtain a heavy gas mixture which has the correct ratio of specific heats and which is nontoxic, nonflammable, thermally stable, chemically inert, and comprised of commercially available components. Calculations were mad… more
Date: 1956
Creator: Chapman, Dean R.
Item Type: Refine your search to only Report
open access

Studies of the speed stability of a tandem helicopter in forward flight

Description: Flight-test measurements, related analytical studies, and corresponding pilots' opinions of the speed stability of tandem-rotor helicopter are presented. An undesirable instability, evidenced by rearward stick motion with increasing forward speed at constant power, is indicated to be caused by variations with speed of the front-rotor downwash at the rear rotor. An analytical expression for predicting changes in speed stability caused by changes in rotor geometry is derived and constants for use… more
Date: June 4, 1953
Creator: Tapscott, Robert J. & Amer, Kenneth B.
Item Type: Refine your search to only Report
open access

The near noise field of static jets and some model studies of devices for noise reduction

Description: An experimental study is presented of the pressure fluctuations near jet exhaust streams made during unchoked operation of a turbojet engine and a 1-inch-diameter high-temperature model jet and during choked operation of various sizes of model jets with unheated air. The tests for unchoked operation indicate a random spectrum of rather narrow band width which varies in frequency content with axial position along the jet. Pressure surveys from the model tests along lines parallel to the 15 degre… more
Date: February 19, 1954
Creator: Lassiter, Leslie W. & Hubbard, Harvey H.
Item Type: Refine your search to only Report
open access

Theoretical and experimental investigation of the effect of tunnel walls on the forces on an oscillating airfoil in two-dimensional subsonic compressible flow

Description: This report presents a theoretical and experimental investigation of the effect of wind-tunnel walls on the air forces on an oscillating wing in two-dimensional subsonic compressible flow. A method of solving an integral equation which relates the downwash on a wing to the unknown loading is given, and some comparisons are made between the theoretical results and the experimental results. A resonance condition, which was predicted by theory in a previous report (NACA report 1150), is shown expe… more
Date: 1956
Creator: Runyan, Harry L.; Woolston, Donald S. & Rainey, A. Gerald
Item Type: Refine your search to only Report
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