National Advisory Committee for Aeronautics (NACA) - 45 Matching Results

Search Results

Results: 1 - 24 next
open access

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.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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
Partner: UNT Libraries Government Documents Department
open access

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
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Bodies of revolution having minimum drag at high supersonic airspeeds

Description: Approximate shapes of nonlifting bodies having minimum pressure foredrag at high supersonic airspeeds are calculated. With the aid of Newton's law of resistance, the investigation is carried out for various combinations of the conditions of given body length, base diameter, surface area, and volume. In general, it is found that when body length is fixed, the body has a blunt nose; whereas, when the length is not fixed, the body has a sharp nose. The additional effect of curvature of the flow ov… more
Date: December 14, 1955
Creator: Eggers, A. J., Jr.; Resnikoff, Meyer M. & Dennis, David H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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
Partner: UNT Libraries Government Documents Department
open access

Charts for Estimating Performance of High-Performance Helicopters

Description: "Theoretically derived charts showing the profile-drag-thrust ratio are presented for helicopter rotors operating in forward flight and having hinged rectangular blades with a linear twist of 0 degree, 8 degrees, and 16 degrees. The charts, showing the profile-drag characteristics of the rotor for various combinations of pitch angle, ratio of thrust coefficient to solidity, and a parameter representing shaft power input, are presented for tip-speed ratios ranging from 0.05 to 0.50. Also present… more
Date: November 23, 1955
Creator: Gessow, Alfred & Tapscott, Robert J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Cloud-droplet ingestion in engine inlets with inlet velocity ratios of 1.0 and 0.7

Description: From Summary: "The paths of cloud droplets into two engine inlets have been calculated for a wide range of meteorological and flight conditions. The amount of water in droplet form ingested by the inlets and the amount and distribution of water impinging on the inlet walls are obtained from these droplet-trajectory calculations. In both types of inlet, a prolate ellipsoid of revolution represents either part or all of the forebody at the center of an annular inlet to an engine. The configuratio… more
Date: November 2, 1955
Creator: Brun, Rinaldo J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

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
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

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.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

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.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Development of craze and impact resistance in glazing plastics by multiaxial stretching

Description: The loss of strength of cast polymethyl methacrylate plastic as a result of crazing is of considerable importance to the aircraft industry. Because of the critical need for basic information on the nature of crazing and the effects of various treatments and environmental conditions on its incidence and magnitude, an investigation of this phenomenon was undertaken. The following factors were examined: (1) the effect of stress-solvent crazing on tensile strength of polymethyl methacrylate; (2) th… more
Date: December 28, 1955
Creator: Kline, G. M.; Wolock, I.; Axilrod, B. M.; Sherman, M. A.; George, D. A. & Cohen, V.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

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
Partner: UNT Libraries Government Documents Department
open access

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.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

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
Partner: UNT Libraries Government Documents Department
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
Partner: UNT Libraries Government Documents Department
open access

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
Partner: UNT Libraries Government Documents Department
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
Partner: UNT Libraries Government Documents Department
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
Partner: UNT Libraries Government Documents Department
open access

Incompressible Flutter Characteristics of Representative Aircraft Wings

Description: "This report gives the results of a detailed study of the flutter characteristics of four representative aircraft wings. This study was made using the electric-analog computer at the California Institute of Technology. During the course of this investigation eight important parameters of each wing were varied and, in addition, the effects of mass, inertia, pitching spring, and location of a concentrated mass were investigated for all four wings and at several sweepback angles" (p. 1385).
Date: June 6, 1955
Creator: Wilts, C. H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Influence of Alloying upon Grain-Boundary Creep

Description: "Grain-boundary displacement, occurring in bicrystals during creep at elevated temperature (350 degrees c), has been measured as a function of the copper content (0.1 to 3 percent) in a series of aluminum-rich aluminum-copper solid-solution alloys. The minimums in stress and temperature, below which grain-boundary motion does not occur, increase regularly with the copper content as would be expected if recovery is necessary for movement. Otherwise, the effects, if any, of the copper solute upon… more
Date: June 24, 1955
Creator: Rhines, F. N.; Bond, W. E. & Kissel, M. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

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.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

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
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Investigation of some wake vortex characteristics of an inclined ogive-cylinder body at Mach number 2

Description: For a body consisting of a fineness-ratio-3 ogival nose tangent to a cylindrical afterbody 7.3 diameters long, pitot-pressure distributions in the flow field, pressure distributions over the body, and downwash distributions along a line through the vortex centers have been measured for angles of attack to 20 degrees. The Reynolds numbers, based on body diameter, were 0.15 x 10 to the 6th power and 0.44 x 10 to the 6th power. Comparisons of computed and measured vortex paths and downwash distrib… more
Date: May 31, 1955
Creator: Jorgensen, Leland H. & Perkins, Edward W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Investigation of the compressive strength and creep lifetime of 2024-T3 aluminum-alloy plates at elevated temperatures

Description: The results of elevated-temperature compressive strength and creep tests of 2024-t3 (formerly 24s-t3) aluminum alloy plates supported in v-grooves are presented. The strength-test results indicate that a relation previously developed for predicting plate compressive strength for plates of all materials at room temperature is also satisfactory for determining elevated-temperature strength. Creep-lifetime results are presented for plates in the form of master creep-lifetime curves by using a time… more
Date: September 8, 1955
Creator: Mathauser, Eldon E. & Deveikis, William D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
Back to Top of Screen