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Preliminary Wind-Tunnel Investigation at Low Speed of Stability and Control Characteristics of Swept Back Wings

Description: Note presenting tests conducted on untapered constant-span wings of 0, 30, 45, and 60 degrees sweepback. The purpose of the tests was to investigate the effect of sweepback on stability and control characteristics. The data showed large changes in longitudinal stability at moderate lift coefficients for the 45 and 60 degree sweptback wings.
Date: April 1946
Creator: Letko, William & Goodman, Alex
Partner: UNT Libraries Government Documents Department

Bending of Rectangular Plates With Large Deflections

Description: Note presenting Von Kármán's equations for thin plates with large deflections are solved for the special cases of rectangular plates with ratios of length to width of 1.5 and 2 and loaded by uniform normal pressure. The boundary conditions are such to approximate panels with riveted edges under normal pressure greater than that of the surrounding panels.
Date: April 1948
Creator: Wang, Chi-Teh
Partner: UNT Libraries Government Documents Department

Measurements of the Nonlinear Variation With Temperature of Heat-Transfer Rate From Hot Wires in Transonic and Supersonic Flow

Description: Note presenting equilibrium temperatures and heat-transfer rates for 0.00015- and 0.00030-inch diameter tungsten wires normal to the flow throughout a range of Mach numbers and Reynolds numbers. For the range of variables, equilibrium temperature of the hot wire is characterized by constant recovery factor for subsonic Mach numbers but constant equilibrium to total temperature ratio for supersonic Mach numbers. Results regarding the equilibrium temperature tests and heat-transfer tests are provided.
Date: April 1957
Creator: Winovich, Warren & Stine, Howard A.
Partner: UNT Libraries Government Documents Department

Investigation of Effects of Surface Temperature and Single Roughness Elements on Boundary-Layer Transition

Description: Note presenting an investigation of the laminar boundary layer and the position of the transition point on a heated flat plate. The Reynolds number of transition was found to decrease as the temperature of the plate is increased. Results regarding the effect of surface temperature, effect of roughness elements, mean-velocity profile near a heated wall, instability of inflection-point profiles, and laminar separation and transition are provided.
Date: April 1947
Creator: Liepmann, Hans W. & Fila, Gertrude H.
Partner: UNT Libraries Government Documents Department

Analysis of Turbulent Flow and Heat Transfer on a Flat Plate at High Mach Numbers With Variable Fluid Properties

Description: From Introduction: "In the turbulent case, however, the results of the various analyses disagree markedly because of the different assumptions made by various authors. These analyses are reviewed in references 1 to 3. The analysis is extended to flow and heat transfer in a boundary layer at high Mach numbers in this paper. (Some preliminary results were presented in ref. 11.)"
Date: April 1958
Creator: Deissler, R. G. & Loeffler, A. L., Jr.
Partner: UNT Libraries Government Documents Department

On Panel Flutter and Divergence of Infinitely Long Unstiffened and Ring-Stiffened Thin-Walled Circular Cylinders

Description: Note presenting a theoretical investigation of the panel flutter and divergence of infinitely long, unstiffened and ring-stiffened thin-walled circular cylinders. Linearized unsteady potential-flow theory is utilized in conjunction with Donnell's cylinder theory to obtain equilibrium equations for panel flutter.
Date: April 1956
Creator: Leonard, Robert W. & Hedgepeth, John M.
Partner: UNT Libraries Government Documents Department

Experiments With Fabrics for Covering Airplane Wings

Description: Note presenting a study of the strength and deformation of the fabric used to cover airplane wings, both undoped and doped. The doping of the fabric with Cellon seems to have a predominant influence on the results according to the nature and number of the coats.
Date: April 1923
Creator: Pröll, A.
Partner: UNT Libraries Government Documents Department

A Fundamental Study of the Mechanism by Which Hydrogen Enters Metals During Chemical and Electrochemical Processing

Description: Note presenting several known methods of controlling the entry and exit of hydrogen in steel as correlated with the known chemical behavior of atomic and molecular hydrogen. Some of the results of testing and a newly proposed mechanism for hydrogen control are provided.
Date: April 1952
Creator: McGraw, L. D.; Snavely, C. A.; Moore, H. L.; Woodberry, P. T. & Faust, C. L.
Partner: UNT Libraries Government Documents Department

Intergranular Corrosion of High-Purity Aluminum in Hydrochloric Acid 2: Grain-Boundary Segregation of Impurity Atoms

Description: Note presenting a study of the strength of the tendency for segregation to the gain boundaries of substitutional solute atoms which differ substantially in size from those of the solvent in single-phase high-purity aluminum through observations on the intergranular corrosion in 20 percent hydrochloric acid.
Date: April 1955
Creator: Metzger, M. & Intrater, J.
Partner: UNT Libraries Government Documents Department

Interim Report on a Fatigue Investigation of a Full-Scale Transport Aircraft Wing Structure

Description: Note presenting results of an investigation of the fatigue strength of several full-scale aircraft wing structures. The 34 fatigue failures which resulted from the tests were of four main types and occurred in three principal localities on the test wings. Results regarding the definition of fatigue failure, load history of specimens, description of fatigue failures, spread in fatigue life, stress concentration factors, rate of crack growth, and effect of fatigue damage on natural frequency and damping are provided.
Date: April 1953
Creator: McGuigan, M. James, Jr.
Partner: UNT Libraries Government Documents Department

Testing Airplane Fabrics

Description: "The following considerations determine the strength of airplane fabrics: 1. maximum air forces acting on the surfaces (including local stresses); 2. tensions produced in the fabrics, in the directions of both warp and filling; 3. factor of safety required. The question of the permissible depression of the fabric as affecting the aerodynamic requirements in regard to the maintenance of shape of the section, the tenacity and extensibility of the layer of dope, its strength and its permeability to water is almost as important" (p. 1).
Date: April 1924
Creator: Pröll, A.
Partner: UNT Libraries Government Documents Department

A Transformation Theory of the Partial Differential Equations of Gas Dynamics

Description: Note presenting a transformation theory of systems of partial differential equations which allows the construction of classes of pressure-density relations depending on parameters for which the equations governing the flow can be transformed into an essentially simpler form, into the system corresponding to the wave equation in the subsonic region, and finally into the form corresponding to the Tricomi equation in the transonic region.
Date: April 1950
Creator: Loewner, Charles
Partner: UNT Libraries Government Documents Department

Turbulent Shearing Stress in the Boundary Layer of Yawed Flat Plates

Description: Note presenting hot-wire anemometer measurements of the turbulent shearing stress in a turbulent boundary layer on a yawed flat plate. The measured velocity profiles are used to calculate the shear distribution and the result is compared with the result of experimental shear measurements.
Date: April 1958
Creator: Ashkenas, Harry
Partner: UNT Libraries Government Documents Department

Torsional Strength of Nickel Steel and Duralumin Tubing as Affected by the Ratio of Diameter to Gage Thickness

Description: "This investigation was made at the request of the Bureau of Aeronautics. Since the ordinary torsion formula is based on elastic resistance to deformation, it is inaccurate for determination of ultimate stresses in thin wall tubing subjected to torsional loads. It has been found that the torsional modulus of rupture varies with the ratio of diameter to gage thickness and the object of these tests was to determine the extent of these variations for subject materials. This is somewhat of a prorogation of work done by the Army Air Service at McCook Field" (p. 1).
Date: April 1924
Creator: Otey, N. S.
Partner: UNT Libraries Government Documents Department

Remarks on the Elastic Axis of Shell Wings

Description: The definitions of flexural center, torsional center, elastic center, and elastic axis are discussed. The calculation of elastic centers is dealt with in principle and a suggestion is made for the design of shear webs.
Date: April 1936
Creator: Kuhn, Paul
Partner: UNT Libraries Government Documents Department

Relation of Journal Bearing Performance to Minimum Oil-Film Thickness

Description: Note presenting the minimum thickness of the oil film as used as a basic variable in performance curves of plain journal bearings under steady load. The load capacity and the predicted film thickness at the hook point of the friction curves are shown to correlate with the peak-to-valley values of surface roughness when misalignment is absent.
Date: April 1958
Creator: Ocvirk, F. W. & DuBois, G. B.
Partner: UNT Libraries Government Documents Department

Results of Edge-Compression on Stiffened Flat-Sheet Panels of Alclad and Nonclad 14S-T6, 24S-T3, and 75S-T6 Aluminum Alloys

Description: Note presenting an investigation made to augment data previously obtained on the compressive strengths of stiffened flat-sheet panels to include the range where ultimate strengths approach the compressive yield strengths of the materials. The sheet materials tested were alclad and nonclad 14S-T6, 24S-T3, and 75S-T6. Results regarding the typical failure, ultimate strengths, rivet failures, and buckling stresses are provided.
Date: April 1954
Creator: Holt, Marshall
Partner: UNT Libraries Government Documents Department

Propeller Tests to Determine the Effect of Number of Blades at Two Typical Solidities

Description: "Propellers with equal total blade area, but with different numbers, were tested at Stanford University. The tests show generally that, for equal total blade area, propellers with the larger number of blades absorb the greater power and, provided hubs have equal drag, develop the higher efficiency. It is shown that the differences found are in agreement, qualitatively, with what might be predicted from simple blade-element theory" (p. 1).
Date: April 1939
Creator: Lesley, E. P.
Partner: UNT Libraries Government Documents Department

Flight Tests of a Helicopter in Autorotation, Including a Comparison With Theory

Description: Note presenting the results of glide performance tests conducted on a test helicopter with its original production blades in the autorotation condition. The data was reduced to coefficient form, and performance at standard sea-level conditions were calculated.
Date: April 1947
Creator: Gessow, Alfred & Myers, Garry C., Jr.
Partner: UNT Libraries Government Documents Department

Note on the Aerodynamic Heating of an Oscillating Surface

Description: Note presenting an analysis of the temperature distributions in a fluid over an oscillating surface with heat transfer and associated heat-transfer parameters are compared with those for the case of conduction at a stationary surface with the same initial temperature potential. It was found that the heat transfer for the oscillating surface can be considerably different from that for conduction alone.
Date: April 1954
Creator: Ostrach, Simon
Partner: UNT Libraries Government Documents Department

A Self-Excited, Alternating-Current, Constant-Temperature Hot-Wire Anemometer

Description: Note presenting a hot-wire anemometer used to study turbojet-engine compressor rotating stall and surge. The system was capable of measuring flow over a frequency range of zero to 500 cycles per second. A description of the anemometer and a description of the dynamic characteristics, static characteristics, and operation and performance are provided.
Date: April 1955
Creator: Shepard, Charles E.
Partner: UNT Libraries Government Documents Department

Effect of Increase in Afterbody Length on the Hydrodynamic Qualities of a Flying-Boat Hull of High Length-Beam Ratio

Description: Report presenting an investigation to determine the effects of increased afterbody length on the hydrodynamic qualities of a model of a flying boat with a hull with a length-beam ratio of 15. Results regarding longitudinal stability, spray characteristics, excess thrust for take-off, landings in waves, and a summary chart are provided.
Date: April 1949
Creator: Kapryan, Walter J. & Clement, Eugene P.
Partner: UNT Libraries Government Documents Department

An Experimental Investigation at Low Speeds of the Effects of Lip Shape on the Drag and Pressure Recovery of a Nose Inlet in a Body of Revolution

Description: Report presenting wind-tunnel tests of a body of revolution with a circular nose inlet conducted at low speeds to ascertain some of the effects of inlet lip bluntness and profile on diffuser performance and body drag. Testing occurred at free-stream Mach numbers up to 0.330 with inlet flows from zero to choking and a steady 0 degree angle of attack and angle of yaw. Results regarding the internal-flow studies with the strut-mounted model and drag and surface-pressure studies with the sting-supported model are provided.
Date: April 1954
Creator: Blackaby, James R. & Watson, Earl C.
Partner: UNT Libraries Government Documents Department

A Mathematical Theory of Plasticity Based on the Concept of Slip

Description: Note presenting a theory of plasticity based on the concept of slip as proposed for the relationship between stress and strain for initially isotropic materials in the strain-hardening range. The theory is an extension to polyaxial stress conditions of the conventional uniaxial stress-strain relation, and time-dependent effects, such as creep and stress relaxation, are not considered.
Date: April 1949
Creator: Batdorf, S. B. & Budiansky, Bernard
Partner: UNT Libraries Government Documents Department