UNT Libraries Government Documents Department - 382 Matching Results

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The Calculation of Pressure on Slender Airplanes in Subsonic and Supersonic Flow

Description: "Under the assumption that a wing, body, or wing-body combination is slender or flying at near sonic velocity, expressions are given which permit the calculation of pressure in the immediate vicinity of the configuration. The disturbance field, in both subsonic and supersonic flight, is shown to consist of two-dimensional disturbance fields extending laterally and a longitudinal field that depends on the streamwise growth of cross-sectional area. A discussion is also given of couplings, between… more
Date: November 28, 1953
Creator: Heaslet, Max A. & Lomax, Harvard
open access

Calculation of the lateral control of swept and unswept flexible wings of arbitrary stiffness

Description: A method similar to that of NACA rep. 1000 is presented for calculating the effectiveness and the reversal speed of lateral-control devices on swept and unswept wings of arbitrary stiffness. Provision is made for using either stiffness curves and root-rotation constants or structural influence coefficients in the analysis. Computing forms and an illustrative example are included to facilitate calculations by means of the method. The effectiveness of conventional aileron configurations and the m… more
Date: April 5, 1951
Creator: Diederich, Franklin W.
open access

Calculations of Laminar Heat Transfer Around Cylinders of Arbitrary Cross Section and Transpiration-Cooled Walls With Application to Turbine Blade Cooling

Description: "An approximate method for the development of flow and thermal boundary layers in the laminar region on cylinders with arbitrary cross section and transpiration-cooled walls is obtained by the use of Karman's integrated momentum equation and an analogous heat-flow equation. Incompressible flow with constant property values throughout the boundary layer is assumed. The velocity and temperature profiles within the boundary layer are approximated by expressions composed of trigonometric functions"… more
Date: June 22, 1951
Creator: Eckert, E. R. G. & Livingood, J. N. B.
open access

Calculations on the forces and moments for an oscillating wing-aileron combination in two-dimensional potential flow at sonic speed

Description: From Summary: "The linearized theory for compressible unsteady flow is used, as suggested in recent contributions to the subject, to obtain the velocity potential and the lift and moment for a thin harmonically oscillating, two-dimensional wing-aileron combination moving at sonic speed. The velocity potential is derived by considering the sonic case as the limit of the linearized supersonic theory. From the velocity potential explicit expressions for the lift and moment are developed for vertic… more
Date: September 4, 1951
Creator: Nelson, Herbert C. & Berman, Julian H.
open access

Calibration of strain-gage installations in aircraft structures for the measurement of flight loads

Description: "A general method has been developed for calibrating strain-gage installations in aircraft structures, which permits the measurement in flight of the shear or lift, the bending moment, and the torque or pitching moment on the principal lifting or control surfaces. Although the stress in structural members may not be a simple function of the three loads of interest, a straightforward procedure is given for numerically combining the outputs of several bridges in such a way that the loads may be o… more
Date: August 12, 1952
Creator: Skopinski, T. H.; Aiken, William S., Jr. & Huston, Wilber B.
open access

Characteristics of the Langley 8-Foot Transonic Tunnel With Slotted Test Section

Description: "A large wind tunnel, approximately 8 feet in diameter, has been converted to transonic operation by means of slots in the boundary extending in the direction of flow. The usefulness of such a slotted wind tunnel, already known with respect to the reduction of the subsonic blockage interference and the production of continuously variable supersonic flows, has been augmented by devising a slot shape with which a supersonic test region with excellent flow quality could be produced. Experimental l… more
Date: July 3, 1958
Creator: Wright, Ray H.; Ritchie, Virgil S. & Pearson, Albin O.
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.
open access

Charts and approximate formulas for the estimation of aeroelastic effects of the lateral control of swept and unswept wings

Description: Charts and approximate formulas are presented for the estimation of static aeroelastic effects on the spanwise lift distribution, rolling-moment coefficient, and rate of roll due to the deflection of ailerons on swept and unswept wings at subsonic and supersonic speeds. Some design considerations brought out by the results of this report are discussed. This report treats the lateral-control case in a manner similar to that employed in NACA Report 1140 for the symmetric-flight case, and is inten… more
Date: 1953
Creator: Foss, Kenneth A. & Diederich, Franklin W.
open access

Charts and approximate formulas for the estimation of aeroelastic effects on the loading of swept and unswept wings

Description: Charts and approximate formulas are presented for the estimation of aeroelastic effects on the spanwise lift distribution, lift-curve slope, aerodynamic center, and damping in roll of swept and unswept wings at subsonic and supersonic speeds. Some design considerations brought out by the results of this report are discussed.
Date: 1953
Creator: Diederich, Franklin W. & Foss, Kenneth A.
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.
open access

Charts for estimating tail-rotor contribution to helicopter directional stability and control in low-speed flight

Description: "Theoretically derived charts and equations are presented by which tail-rotor design studies of directional trim and control response at low forward speed can be conveniently made. The charts can also be used to obtain the main-rotor stability derivatives of thrust with respect to collective pitch and angle of attack at low forward speeds. The use of the charts and equations for tail-rotor design studies is illustrated. Comparisons between theoretical and experimental results are presented. The… more
Date: October 27, 1953
Creator: Amer, Kenneth B. & Gessow, Alfred
open access

Charts Relating the Compressive Buckling Stress of Longitudinally Supported Plates to the Effective Deflectional and Rotational Stiffness of the Supports

Description: "A stability analysis is made of a long flat rectangular plate subjected to a uniform longitudinal compressive stress and supported along its longitudinal edges and along one or more longitudinal lines by elastic line supports. The elastic supports possess deflectional and rotational stiffness. Such configuration is an idealization of the compression cover skin and internal structure of a wing and tail surfaces" (p. 1).
Date: 1954
Creator: Anderson, Roger A. & Semonian, Joseph W.
open access

Chordwise and Compressibility Corrections to Slender-Wing Theory

Description: Corrections to slender-wing theory are obtained by assuming a spanwise distribution of loading and determining the chordwise variation which satisfies the appropriate integral equation. Such integral equations are set up in terms of the given vertical induced velocity on the center line or, depending on the type of wing plan form, its average value across the span at a given chord station. The chordwise distribution is then obtained by solving these integral equations. Results are shown for fla… more
Date: November 28, 1952
Creator: Lomax, Harvard & Sluder, Loma
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.
open access

A comparative analysis of the performance of long-range hypervelocity vehicles

Description: From Summary: "Long-range hypervelocity vehicles are studied in terms of their motion in powered flight. Powered flight is analyzed for an idealized propulsion system which approximates rocket motors. Unpowered flight is characterized by a return to earth along a ballistic, skip, or glide trajectory. Only those trajectories are treated which yield the maximum range for a given velocity at the end of powered flight. Aerodynamic heating is treated in a manner similar to that employed previously b… more
Date: December 10, 1954
Creator: Eggers, Alfred J., Jr.; Allen, H. Julian & Neice, Stanford E.
open access

Comparison between theory and experiment for wings at supersonic speeds

Description: This paper presents a critical comparison made between experimental and theoretical results for the aerodynamic characteristics of wings at supersonic flight speeds. As a preliminary, a brief, nonmathematical review is given of the basic assumptions and general findings of supersonic wing theory in two and three dimensions. Published data from two-dimensional pressure-distribution tests are then used to illustrate the effects of fluid viscosity and to assess the accuracy of linear theory as com… more
Date: May 3, 1950
Creator: Vincenti, Walter G.
open access

Comparison of effectiveness of convection-, transpiration-, and film-cooling methods with air as coolant

Description: From Summary: "Various parts of aircraft propulsion engines that are in contact with hot gases often require cooling. Transpiration and film cooling, new methods that supposedly utilize cooling air more effectively than conventional convection cooling, have already been proposed. This report presents material necessary for a comparison of the cooling requirements of these three methods. Correlations that are regarded by the authors as the most reliable today are employed in evaluating each of t… more
Date: July 9, 1953
Creator: Eckert, E. R. G. & Livingood, John N. B.
open access

Comparison of High-Speed Operating Characteristics of Size 215 Cylindrical-Roller Bearings as Determined in Turbojet Engine and in Laboratory Test Rig

Description: A comparison of the operating characteristics of 75-millimeter-bore (size 215) cylindrical-roller one-piece inner-race-riding cage-type bearings was made by means of a laboratory test rig and a turbojet engine. Cooling correlation parameters were determined by means of dimensional analysis, and the generalized results for both the inner- and the outer-race bearing operating temperatures are computed for the laboratory test rig and the turbojet engine. A method is given that enables the designer… more
Date: 1952
Creator: Macks, E. Fred & Nemeth, Zolton N.
open access

Comparison of performance of experimental and conventional cage designs and materials for 75-millimeter-bore cylindrical roller bearings at high speed

Description: From Summary: "The results of two investigations, one to determine the relative merits of four experimental and two conventional design 75-millimeter-bore (size 215) cylindrical roller bearings and one to determine the relative merits of nodular iron and bronze as cage materials for this size and type of bearing, are presented in this report. Nine test bearings were operated over a range of dn values (product of bearing bore in mm and shaft speed in r.p.m) from 0.3 x 10(6) to 2.3 x 20(6), radia… more
Date: June 30, 1954
Creator: Anderson, William J.; Macks, E. Fred & Nemeth, Zolton N.
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: From Summary: "Several methods of obtaining the time response of Linear systems to either a unit impulse or an arbitrary input from frequency-response data are described and compared. Comparisons indicate that all the methods give good accuracy when applied to a second-order system; the main difference is the required computing time. The methods generally classified as inverse Laplace transform methods were found to be most effective in determining the response to a unit impulse from frequency-… more
Date: March 16, 1956
Creator: Donegan, James J. & Huss, Carl R.
open access

A comparison of the experimental subsonic pressure distributions about several bodies of revolution with pressure distributions computed by means of the linearized theory

Description: "An analysis is made of the effects of compressibility on the pressure coefficients about several bodies of revolution by comparing experimentally determined pressure coefficients with corresponding pressure coefficients calculated by the use of the linearized equations of compressible flow. The results show that the theoretical methods predict the subsonic pressure-coefficient changes over the central part of the body but do not predict the pressure-coefficient changes near the nose. Extrapola… more
Date: November 5, 1951
Creator: Matthews, Clarence W.
open access

A Comparison of the Spanwise Loading Calculated by Various Methods With Experimental Loadings Obtained on a 45 Degree Sweptback Wing of Aspect Ratio 8.02 at a Reynolds Number of 4.0 X 10(6)

Description: "This report compares the experimental force and moment data obtained by pressure measurements on a wing of aspect ratio 8.02, 45 degree sweptback of the quarter-chord line, taper ratio of 0.45, and NACA 63(sub 1)A012 airfoil sections with the calculated loadings obtained by the standard methods proposed by Weissinger, Falkner, and Multopp, as well as by several variations of these methods" (p. 1175).
Date: August 14, 1951
Creator: Schneider, William C.
open access

A comparison of theory and experiment for high-speed free-molecule flow

Description: A comparison is made of free-molecule-flow theory with the results of wind-tunnel tests performed to determine the drag and temperature-rise characteristics of a transverse circular cylinder. The measured values of the cylinder center-point temperature confirmed the salient point of the heat-transfer analysis which was the prediction that an insulated cylinder would attain a temperature higher than the stagnation temperature of the stream. Good agreement was obtained between the theoretical and… more
Date: September 12, 1950
Creator: Stalder, Jackson R.; Goodwin, Glen & Creager, Marcus O.
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