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Analog study of interacting and noninteracting multiple-loop control systems for turbojet engines

Description: The results of an analog investigation of several turbojet-engine control configurations is presented in this report. Both proportional and proportional-plus-integral controllers were studied, and compensating terms for engine interaction were added to the control system. Data were obtained on the stability limits and the transient responses of these various configurations. Analytical expressions in terms of the component transfer functions were developed for the configurations studied, and the… more
Date: 1955
Creator: Pack, George J. & Phillips, W. E., Jr.
Partner: UNT Libraries Government Documents Department
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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.
Partner: UNT Libraries Government Documents Department
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Determination of lateral-stability derivatives and transfer-function coefficients from frequency-response data for lateral motions

Description: A method is presented for determining the lateral-stability derivatives, transfer-function coefficients, and the modes for lateral motion from frequency-response data for a rigid aircraft. The method is based on the application of the vector technique to the equations of lateral motion, so that the three equations of lateral motion can be separated into six equations. The method of least squares is then applied to the data for each of these equations to yield the coefficients of the equations o… more
Date: 1955
Creator: Donegan, James J.; Robinson, Samuel W., Jr. & Gates, Ordway B., Jr.
Partner: UNT Libraries Government Documents Department
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Effects of Wing Position and Fuselage Size on the Low-Speed Static Rolling Stability Characteristics of a Delta-Wing Model

Description: "An investigation was made to determine the effects of wing position and fuselage size on the low-speed static and rolling stability characteristics of airplane models having a triangular wing and vertical tail surfaces. For the longitudinal-stability case, the results indicated that, for all wing positions, as the fuselage size was increased the maximum lift coefficient decreased. Also, for a given fuselage size, the maximum lift coefficient increased as the wing position was changed from low … more
Date: 1955
Creator: Goodman, Alex & Thomas, David F., Jr.
Partner: UNT Libraries Government Documents Department
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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.
Partner: UNT Libraries Government Documents Department
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An Investigation of the Maximum Lift of Wings at Supersonic Speeds

Description: This report presents the results of an exploratory investigation carried out in the Langley 9-inch supersonic tunnel to determine the maximum lift of wings operating at supersonic speeds. A variety of wing plan forms of random thickness distributions were tested at Mach numbers of 1.55, 1.90, and 2.32 and at Reynolds numbers varying between 0.74 x 10(6) and 0.27 x 10(6) at angles of attack ranging from zero up through the angle at which maximum lift occurred. Subsequent pressure-distribution te… more
Date: 1955
Creator: Gallagher, James J. & Mueller, James N.
Partner: UNT Libraries Government Documents Department
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Measurement and Analysis of Wing and Tail Buffeting Loads on a Fighter Airplane

Description: "The buffeting loads measured on the wing and tail of a fighter airplane during 194 maneuvers are given in tabular form, along with the associated flight conditions. Measurements were made at altitudes of 30,000 to 10,000 feet and at speeds up to a Mach number of 0.8. Least-squares methods have been used for a preliminary analysis of the data. The agreement between the results of this analysis and the loads measured in stalls is sufficiently good to suggest the examination of the buffeting of o… more
Date: 1955
Creator: Huston, Wilber B. & Skopinski, T. H.
Partner: UNT Libraries Government Documents Department
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On the Kernel function of the integral equation relating the lift and downwash distributions of oscillating finite wings in subsonic flow

Description: This report treats the Kernel function of an integral equation that relates a known prescribed downwash distribution to an unknown lift distribution for a harmonically oscillating finite wing in compressible subsonic flow. The Kernel function is reduced to a form that can be accurately evaluated by separating the Kernel function into two parts: a part in which the singularities are isolated and analytically expressed and a nonsingular part which may be tabulated. The form of the Kernel function… more
Date: 1955
Creator: Watkins, Charles E.; Runyan, Harry L. & Woolston, Donald S.
Partner: UNT Libraries Government Documents Department
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Standard Atmosphere - Tables and Data for Altitudes to 65,800 Feet

Description: Report includes calculated detailed tables of pressures and densities of a standard atmosphere in both metric and english units for altitudes from -5,000 meters to 20,000 meters and from -16,500 feet to 65,800 feet. Tables, figures, physical constants, and basic equations are based upon the text, reproduced herein, of the manual of the ICAO standard atmosphere, International Civil Aviation Organization (ICAO) draft of December 1952.
Date: 1955
Partner: UNT Libraries Government Documents Department
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Statistical measurements of contact conditions of 478 transport-airplane landings during routine daytime operations

Description: Statistical measurements of contact conditions have been obtained, by means of a special photographic technique, of 478 landings of present-day transport airplanes made during routine daylight operations in clear air at the Washington National Airport. From the measurements, sinking speeds, rolling velocities, bank angles, and horizontal speeds at the instant before contact have been evaluated and a limited statistical analysis of the results has been made and is reported in this report.
Date: 1955
Creator: Silsby, Norman S.
Partner: UNT Libraries Government Documents Department
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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.
Partner: UNT Libraries Government Documents Department
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Theoretical and experimental investigation of heat transfer by laminar natural convection between parallel plates

Description: Results are presented of a theoretical and experimental investigation of heat transfer involving laminar natural convection of fluids enclosed between parallel walls oriented in the direction of the body force, where one wall is heated uniformly, and the other is cooled uniformly. For the experimental work, parallel walls were simulated by using an annulus with an inner-to-outer diameter ratio near 1. The results of the theoretical investigation are presented in the form of equations for the ve… more
Date: 1955
Creator: Lietzke, A. F.
Partner: UNT Libraries Government Documents Department
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A Theoretical and Experimental Investigation of the Lift and Drag Characteristics of Hydrofoils at Subcritical and Supercritical Speeds

Description: "A theoretical and experimental investigation at subcavitation speeds was made of the effect of the free-water surface and rigid boundaries on the lift and drag of an aspect-ratio-10 hydrofoil at both subcritical and supercritical speeds and of an aspect ratio-4 hydrofoil at supercritical speeds. Approximate theoretical solutions for the effects of the free-water surface and rigid boundaries on drag at subcritical speeds are developed. An approximate theoretical solution for the effects of thes… more
Date: 1955
Creator: Wadlin, Kenneth L.; Shuford, Charles L., Jr. & McGehee, John R.
Partner: UNT Libraries Government Documents Department
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Interaction of a Free Flame Front With a Turbulence Field

Description: "Small-perturbation spectral-analysis techniques are used to obtain the root-mean-square flame-generated turbulence velocities and the attenuating pressure fluctuations stemming from interaction of a constant-pressure flame front with a field of isotropic turbulence in the absence of turbulence decay processes. The anisotropic flame-generated turbulence velocities are found to be of about the same intensity as those of the incident isotropic turbulence, the lateral turbulence velocities being a… more
Date: January 25, 1955
Creator: Tucker, Maurice
Partner: UNT Libraries Government Documents Department
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The Compressible Laminar Boundary Layer with Heat Transfer and Arbitrary Pressure Gradient

Description: "An approximate method for the calculation of the compressible laminar boundary layer with heat transfer and arbitrary pressure gradient, based on Thwaites' correlation concept, is presented. With the definition of dimensionless shear and heat-transfer parameters and an assumed correlation of these parameters in terms of a momentum parameter, a complete system of relations for calculating skin friction and heat transfer results. Knowledge of velocity or temperature profiles is not necessary in … more
Date: February 1, 1955
Creator: Cohen, Clarence B. & Reshotko, Eli
Partner: UNT Libraries Government Documents Department
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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
Partner: UNT Libraries Government Documents Department
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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.
Partner: UNT Libraries Government Documents Department
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Contributions on the Mechanics of Boundary-Layer Transition

Description: "The manner in which flow in a boundary layer becomes turbulent was investigated on a flat plate at wind speeds generally below 100 feet per second. Hot-wire techniques were used, and many of the results are derived from oscillograms of velocity fluctuations in the transition region. Following a presentation of the more familiar aspects of transition, there are presented the very revealing facts discovered while studying the characteristics of artificially produced turbulent spots" (p. 853).
Date: February 28, 1955
Creator: Schubauer, G. B. & Klebanoff, P. S.
Partner: UNT Libraries Government Documents Department
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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
Partner: UNT Libraries Government Documents Department
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An analysis of once-per-revolution oscillating aerodynamic thrust loads on single-rotation propellers on tractor airplanes at zero yaw

Description: A simplified procedure is shown for calculating the once-per-revolution oscillating aerodynamic thrust loads on propellers of tractor airplanes at zero yaw. The only flow field information required for the application of the procedure is a knowledge of the upflow angles at the horizontal center line of the propeller disk. Methods are presented whereby these angles may be computed without recourse to experimental survey of the flow field. The loads computed by the simplified procedure are compar… more
Date: March 21, 1955
Creator: Rogallo, Vernon L.; Yaggy, Paul F. & McCloud, John L., III
Partner: UNT Libraries Government Documents Department
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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
Partner: UNT Libraries Government Documents Department
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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
Partner: UNT Libraries Government Documents Department
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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.
Partner: UNT Libraries Government Documents Department
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Influence of Hot-Working Conditions on High-Temperature Properties of a Heat-Resistant Alloy

Description: "The relationships between conditions of hot-working and properties at high temperatures and the influence of the hot-working on response to heat treatment were investigated for an alloy containing nominally 20 percent molybdenum, 2 percent tungsten, and 1 percent columbium. Commercially produced bar stock was solution-treated at 2,200 degrees F. to minimize prior-history effects and then rolled at temperatures of 2,200 degrees, 2,100 degrees, 2,000 degrees, 1,800 degrees, and 1,600 degrees F. … more
Date: May 20, 1955
Creator: Ewing, John F. & Freeman, J. W.
Partner: UNT Libraries Government Documents Department
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