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Flow induced by a rotor in power-on vertical descent

Description: From Summary: "Approximate equations are derived for the induced power required and blade loading of a lifting rotor operating in the power-on vertical-descent range. The approximate relations, which are based upon certain assumptions as to the nature of the flow pattern, yield, for the induced power variation, results which are in general agreement with the available experiment data."
Date: July 1958
Creator: Castles, Walter, Jr.
Partner: UNT Libraries Government Documents Department
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Lift and Pitching Moment at Supersonic Speeds Due to Constant Vertical Acceleration for Thin Sweptback Tapered Wings With Streamwise Tips: Supersonic Leading and Trailing Edges

Description: Note presenting the nondimensional lift derivative and the corresponding pitching-moment derivative resulting from constant vertical acceleration as evaluated for a family of thin sweptback tapered wings with streamwise tips traveling at supersonic speeds. The analysis is applicable at those speeds for which the wing leading and trailing edges are both supersonic, provided that the Mach lines from the wing apex intersect the trailing edge and that the Mach line from the leading edge of one tip … more
Date: July 1954
Creator: Cole, Isabella J. & Margolis, Kenneth
Partner: UNT Libraries Government Documents Department
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Theoretical Investigation at Subsonic Speeds of the Flow Ahead of a Slender Inclined Parabolic-Arc Body of Revolution and Correlation With Experimental Data Obtained at Low Speeds

Description: Report presenting charts which permit the rapid estimation of deviations from free-stream values of static pressure, angle of attack, and angle of sideslip so that ideal positions for orifices and vanes for measuring these qualities can be selected. The effects of thickness and angle of attack are considered in greater detail.
Date: July 1954
Creator: Letko, William & Danforth, Edward C. B., III
Partner: UNT Libraries Government Documents Department
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General Instability of Stiffened Cylinders

Description: "Theoretical buckling stresses are determined in explicit form for circular cylinders with circumferential and axial stiffening. The loadings are axial compression, radial pressure, hydrostatic pressure, and torsion. Analyses were confined to moderate-length and long cylinders" (p. 1).
Date: July 1958
Creator: Becker, Herbert
Partner: UNT Libraries Government Documents Department
open access

Effects of fixing transition on the transonic aerodynamic characteristics of a wing-body configuration at Reynolds numbers from 2.4 to 12 million

Description: Report presenting a wind-tunnel investigation of the effects of fixing boundary-layer transition with wires on the aerodynamic characteristics of a wing-body configuration at a range of Mach numbers. The model consisted of an aspect-ratio-3 trapezoidal wing with a 3-percent-thick biconvex section in combination with a Sears-Haack body of revolution. Results regarding lift characteristics, pitching-moment characteristics, and drag characteristics are provided.
Date: July 1958
Creator: Hunton, Lynn W.
Partner: UNT Libraries Government Documents Department
open access

An Estimate of the Fluctuating Surface Pressures Encountered in the Reentry of a Ballistic Missile

Description: Note presenting calculations made of the magnitude of the surface sound pressure levels that will occur on blunt-nosed vehicles during reentry into the earth's atmosphere. The results presented cover a wide range of re-entrance velocities and reentrance angles into the atmosphere and sizes and weights of the vehicle.
Date: July 1958
Creator: Callaghan, Edmund E.
Partner: UNT Libraries Government Documents Department
open access

Effect of Phosphate Coatings on Temperature of Metal Parts Exposed to Flame Environments

Description: Note presenting an investigation of the effect of phosphate coatings on the temperature of metal specimens placed in a flame. Small cylindrical specimens of mild steel and S-816 alloy were placed in a natural-gas-air flame at specific temperatures. Special attention is given to the fact that temperature drop was noted in certain specimens and the potential reasons for this reaction are explored.
Date: July 1956
Creator: Fryburg, George C.; Katz, Norman H. & Simon, Sidney L.
Partner: UNT Libraries Government Documents Department
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Method of Split Rigidities and Its Application to Various Buckling Problems

Description: Note presenting a comprehensive review on the method of split rigidities. The principles on which the method is based are discussed and it is shown how these principles are applied. The method is applied to several examples of using this method to calculate buckling stresses of structures that buckle in composite modes.
Date: July 1958
Creator: Bijlaard, P. P.
Partner: UNT Libraries Government Documents Department
open access

A review of the thermodynamic, transport, and chemical reaction rate properties of high-temperature air

Description: Thermodynamic and transport properties of high temperature air, and the reaction rates for the important chemical processes which occur in air, are reviewed. Semiempirical, analytic expressions are presented for thermodynamic and transport properties of air. Examples are given illustrating the use of these properties to evaluate (1) equilibrium conditions following shock waves, (2) stagnation region heat flux to a blunt high-speed body, and (3) some chemical relaxation lengths in stagnation reg… more
Date: July 1958
Creator: Hansen, C. Frederick & Heims, Steve P.
Partner: UNT Libraries Government Documents Department
open access

Screen-type noise reduction devices for ground running of turbojet engines

Description: Report presenting testing of the use of screens placed across the jet as a means of suppressing jet noise during ground running, which was somewhat offset by increased noise levels ahead of the engine. Air-jet tests showed negligible reduction in sound generation with additional screens. The large reductions obtained by using screens show that noise generated inside the engine by the turbine or combustion contribute only a minor part of the total noise.
Date: July 1957
Creator: Coles, Willard D. & North, Warren J.
Partner: UNT Libraries Government Documents Department
open access

Recovery and time-response characteristics of six thermocouple probes in subsonic and supersonic flow

Description: Experimental data obtained from three shielded and three unshielded thermocouple probes are presented. Data taken in air at room temperature over the ranges 0.2 to 2.2 Mach number and 0.2 to 2.2 atmospheres total pressure show reproducible systematic variations of recovery with Mach number, ambient pressure, flow angle, and probe design. Time-constant data determined at Mach 0.2 and room temperature and pressure indicate that unshielded probes are several times faster in response to temperature… more
Date: July 1955
Creator: Stickney, Truman M.
Partner: UNT Libraries Government Documents Department
open access

An experimental study of the lift and pressure distribution on a double-wedge profile at Mach numbers near shock attachment

Description: Report presenting an account of wind-tunnel measurements at low supersonic speeds of the pressure distribution on a doubly symmetrical double-wedge profile of approximately 8-percent thickness. The results cover a range of Mach numbers, angles of attack, and a specified Reynolds number. Results regarding the characteristics at zero angle of attack, characteristics at angle of attack, comparison with subsonic results, and some general remarks are provided.
Date: July 1954
Creator: Vincenti, Walter G.; Dugan, Duane W. & Phelps, E. Ray
Partner: UNT Libraries Government Documents Department
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Idealized wings and wing-bodies at a Mach number of 3

Description: Report presenting the theoretical possibilities for obtaining high lift-drag ratios at M = 3 and to describe some experiments designed to exploit the theory. Relatively high lift-drag ratios calculated were partly realized at low wind-tunnel Reynolds numbers. The rate of increase in maximum lift-drag ratio with increased Reynolds number was greater than expected, which indicated a need for more experiments at conditions closer to actual flight.
Date: July 1958
Creator: Katzen, Elliott D.
Partner: UNT Libraries Government Documents Department
open access

Correction of additional span loadings computed by the Weissinger seven-point method for moderately tapered wings of high aspect ratio

Description: Because the Weissinger seven-point results were found to be in error for wings combining high aspect ratio with large amounts of sweep, a simple procedure is demonstrated which corrects errors and results in more accurate span loadings read directly from loading charts. The procedure consists of an alteration of the taper ratio used plus an additional correction applied at the wing root.
Date: July 1955
Creator: DeYoung, John & Barling, Walter H., Jr.
Partner: UNT Libraries Government Documents Department
open access

Heat-transfer and pressure measurements on flat-faced cylinders at a Mach number of 2

Description: Report presenting flat-faced cylinders tested at Mach number 2 and sea-level conditions in the preflight jet. Both pressure distributions and heat-transfer rates were measured. Results regarding pressure measurements and heat-transfer measurements are provided.
Date: July 1958
Creator: Stoney, William E., Jr. & Markley, J. Thomas
Partner: UNT Libraries Government Documents Department
open access

Temperatures, thermal stress, and shock in heat-generating plates of constant conductivity and of conductivity that varies linearly with temperature

Description: Report presenting working formulas for the steady-state temperatures and thermal stress in heat-generating infinite plates of constant conductivity. Of all planes in the plate, the plate surfaces are always under the greatest tension, and the midplane is under the greatest compression.
Date: July 1953
Creator: Manson, S. V.
Partner: UNT Libraries Government Documents Department
open access

The High-Speed Planing Characteristics of a Rectangular Flat Plate Over a Wide Range of Trim and Wetted Length

Description: Note presenting an investigation of the principal high-speed planing characteristics for a prismatic surface with an angle of dead rise of 0 degrees determined over a wide range of planing variables. Wetted length, resistance, center-of-pressure location, and draft were determined at speed coefficients ranging up to 25.0, beam loadings up to 87.3, and trims up to 30 degrees.
Date: July 1953
Creator: Weinstein, Irving & Kapryan, Walter J.
Partner: UNT Libraries Government Documents Department
open access

Recent research on the creep of airframe components

Description: Report presenting the results of research on the creep of airframe components at elevated temperatures. Experimental lifetime data from creep tests of stainless-steel plates and aluminum-alloy unstiffened circular cylinders are presented and compared with results predicted from isochronous stress-strain curves.
Date: July 1957
Creator: Mathauser, Eldon E.; Berkovits, Avraham & Stein, Bland A.
Partner: UNT Libraries Government Documents Department
open access

Effects of Boundary-Layer Displacement and Leading-Edge Bluntness on Pressure Distribution, Skin Friction, and Heat Transfer of Bodies at Hypersonic Speeds

Description: "Results are presented of an investigation to determine the effect of boundary-layer displacement and leading-edge bluntness on surfaces in hypersonic flow. The presence of the boundary layer and the blunt leading edge induce pressure gradients which in turn affect the skin friction and heat transfer to the surface. Methods for predicting these phenomena on two-dimensional surfaces are given and a brief review of recent three-dimensional results is presented" (p. 1).
Date: July 1958
Creator: Bertram, Mitchel H. & Henderson, Arthur, Jr.
Partner: UNT Libraries Government Documents Department
open access

The calculation of downwash behind wings of arbitrary plan form at supersonic speeds

Description: Report presenting exact and approximate methods based on linearized supersonic flow theory for the calculation of the velocity potential and the downwash from thin wings of arbitrary plan form. The applicability of the method inherently depends on a knowledge of the load distribution over the plan form of the wing.
Date: July 1950
Creator: Martin, John C.
Partner: UNT Libraries Government Documents Department
open access

Analytical and Experimental Investigation of Adiabatic Turbulent Flow in Smooth Tubes

Description: Note presenting equations derived for the prediction of velocity distributions for fully developed adiabtic turbulent flow in smooth tubes; both the incompressible and compressible flow cases were treated. The analysis produced a single equation that represents flow in both the conventional buffer layer and the laminar layer. The results for fully developed flow were correlated by using conventional dimensionless velocity and distance parameters, and agreed closely with those of Nikuradse and o… more
Date: July 1950
Creator: Deissler, Robert G.
Partner: UNT Libraries Government Documents Department
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Effect of Variation in Rivet Diameter and Pitch on the Average Stress at Maximum Load for 24S-T3 and 75S-T6 Aluminum-Alloy, Flat, Z-Stiffened Panels That Fail by Local Instability

Description: "A study is made of the effect of variation in diameter and pitch of A17S-T4 aluminum-alloy flat-head rivets on the average stress at maximum load for 24S-T3 and 75S-T6 aluminum-alloy, flat, Z-stiffened panels that fail by local instability. A curve is presented for determining the diameter and pitch required to insure the development of a given average stress for local instability" (p. 1).
Date: July 1950
Creator: Dow, Norris F. & Hickman, William A.
Partner: UNT Libraries Government Documents Department
open access

Comparison of several methods for obtaining the time response of linear systems to either a unit impulse or arbitrary input from frequency-response data

Description: Report presenting a description and comparison of several methods of obtaining the time response of linear systems to either a unit impulse or an arbitrary input from frequency-response data. All of the methods give good accuracy when applied to a second-order system; the main difference is the required computing time.
Date: July 1956
Creator: Donegan, James J. & Huss, Carl R.
Partner: UNT Libraries Government Documents Department
open access

Investigation of the Laminar Aerodynamic Heat-Transfer Characteristics of a Hemisphere-Cylinder in the Langley 11-inch Hypersonic Tunnel at a Mach Number of 6.8

Description: Note presenting a program to investigate the aerodynamic heat transfer of a non-isothermal hemisphere-cylinder in the 11-inch hypersonic tunnel at a Mach number of 6.8. Results regarding pressure distribution, laminar recovery factor, temperature distribution, heat-transfer parameters, average heat-transfer coefficient, and schileren observations.
Date: July 1956
Creator: Crawford, Davis H. & McCauley, William D.
Partner: UNT Libraries Government Documents Department
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