UNT Libraries Government Documents Department - 13,786 Matching Results

Search Results

prev Results: 13291 - 13314 next
open access

Study of Aluminum Deformation by Electron Microscopy

Description: Note presenting an investigation of the slip-line structure in a series of aluminum single crystals deformed in tension in an electron microscope. In several of the crystals, the slip-line structure was examined after successive steps in the elongation.
Date: August 1956
Creator: Young, A. P.; Melton, C. W. & Schwartz, C. M.
Item Type: Refine your search to only Report
open access

Investigation of performance of 9-cylinder engine using large valve overlap and eclipse fuel-injection system

Description: Report presenting single-cylinder tests were made with several different engines over a period of time, which have shown that a large overlap between the time of inlet valve opening and exhaust valve closing results in a considerable increase in the maximum power obtainable from a supercharged engine and reduces cylinder temperatures.
Date: November 1941
Creator: Young, Alfred W.
Item Type: Refine your search to only Report
open access

Power Unit for High-Intensity Light Source

Description: "A light-source power unit has been developed that provides reliable trigger, and easy synchronization with rotating elements or electric impulses. When used with conventional spark gaps and flash tubes, this power unit provides a light pulse of high intensity and short duration" (p. 1).
Date: July 9, 1951
Creator: Young, Allen E.; McCullough, Stuart & Smith, Richard L.
Item Type: Refine your search to only Report
open access

Experimental Study of Isothermal Wake-Flow Characteristics of Various Flame-Holder Shapes

Description: "An investigation of the isothermal wake-flow characteristics of several flame-holder shapes was carried out in a 4- by 4-inch flow chamber. The effects of flame-holder-shape changes on the characteristics of the Karman vortices and thus on the recirculation zones to which experimenters have related the combustion process were obtained for several flame holders. The results may furnish a basis of correlation, of combustion efficiency and stability for similarly shaped flame holders in combustio… more
Date: January 23, 1952
Creator: Younger, George G.; Gabriel, David S. & Mickelsen, William R.
Item Type: Refine your search to only Report
open access

A Short Method of Calculating Torsional Stresses in an Airplane Fuselage

Description: "This report deals with an investigation carried out in the Civil Engineering Laboratory of the University of California, to determine the accuracy of existing methods of computing the stresses in an airplane fuselage when subjected to torsion, and to derive a simple approximate formula for the rapid calculation of these stresses. The formula is derived by using the customary least work equation and considering each bay separately" (p. 1).
Date: September 1924
Creator: Younger, John E.
Item Type: Refine your search to only Report
open access

On the Vortex Sound from Rotating Rods

Description: "The motion of different bodies immersed in liquid or gaseous media is accompanied by characteristic sound which is excited by the formation of unstable surfaces of separation behind the body, usually disintegrating into a system of discrete vortices (such as the Karman vortex street due to the flow about an infintely long rod, etc.). In the noise from fans, pumps, and similar machinery, vortex noise frequently predominates. The purpose of this work is to elucidate certain questions of the depe… more
Date: March 1947
Creator: Yudin, E. Y.
Item Type: Refine your search to only Report
open access

An automatic speed control for wind tunnels

Description: Described here is an automatic control that has been used in several forms in wind tunnels at the Washington Navy Yard. The form now in use with the 8-foot tunnel at the Navy Yard is considered here. Details of the design and operation of the automatic control system are given. Leads from a Pitot tube are joined to an inverted cup manometer located above a rheostat. When the sliding weight of this instrument is set to a given notch, say for 40 m.p.h, the beam tip vibrates between two electric c… more
Date: February 1928
Creator: Zahm, A. F.
Item Type: Refine your search to only Report
open access

Development of Air Speed Nozzles

Description: Report describes the development of a suitable speed nozzle for the first few thousand airplanes made by the United States during the recent war in Europe, and to furnish a basis for more mature instruments in the future. Requirements for the project were to provide a suitable pressure collector for aircraft speed meters and to develop a speed nozzle which would be waterproof, powerful, unaffected by slight pitch and yaw, rugged and easy to manufacture, and uniform in structure and reading, so … more
Date: 1920
Creator: Zahm, A. F.
Item Type: Refine your search to only Report
open access

Flow and Drag Formulas for Simple Quadrics

Description: The pressure distribution and resistance found by theory and experiment for simple quadrics fixed in an infinite uniform stream of practically incompressible fluid are calculated. The experimental values pertain to air and some liquids, especially water; the theoretical refer sometimes to perfect, again to viscid fluids. Formulas for the velocity at all points of the flow field are given. Pressure and pressure drag are discussed for a sphere, a round cylinder, the elliptic cylinder, the prolate… more
Date: December 1979
Creator: Zahm, A. F.
Item Type: Refine your search to only Report
open access

Flow and Drag Formulas for Simple Quadrics

Description: This report gives the pressure distribution and resistance found by theory and experiment for simple quadrics fixed in an infinite uniform stream of practically incompressible fluid. The experimental values pertain to air and some liquids, especially water; the theoretical refer sometimes to perfect, again to viscid fluids. For the cases treated the concordance of theory and measurement is so close as to make a resume of results desirable. Incidentally formulas for the velocity at all points of… more
Date: 1927
Creator: Zahm, A. F.
Item Type: Refine your search to only Report
open access

Flow and Force Equations for a Body Revolving in a Fluid

Description: A general method for finding the steady flow velocity relative to a body in plane curvilinear motion, whence the pressure is found by Bernoulli's energy principle is described. Integration of the pressure supplies basic formulas for the zonal forces and moments on the revolving body. The application of the steady flow method for calculating the velocity and pressure at all points of the flow inside and outside an ellipsoid and some of its limiting forms is presented and graphs those quantities … more
Date: December 1979
Creator: Zahm, A. F.
Item Type: Refine your search to only Report
open access

Flow and Force Equations for a Body Revolving in a Fluid

Description: Part I gives a general method for finding the steady-flow velocity relative to a body in plane curvilinear motion, whence the pressure is found by Bernoulli's energy principle. Integration of the pressure supplies basic formulas for the zonal forces and moments on the revolving body. Part II, applying this steady-flow method, finds the velocity and pressure at all points of the flow inside and outside an ellipsoid and some of its limiting forms, and graphs those quantities for the latter forms.… more
Date: December 17, 1928
Creator: Zahm, A. F.
Item Type: Refine your search to only Report
open access

Horizontal Buoyancy in Wind Tunnels

Description: Note presenting an examination of horizontal buoyancy in wind tunnels, including an examination of the relative flow, static pressure gradient, horizontal buoyancy computation, and methods of computation in practical use are provided.
Date: November 1920
Creator: Zahm, A. F.
Item Type: Refine your search to only Report
open access

Periodic Stresses in Gyroscopic Bodies, With Applications to Air Screws

Description: Report discusses periodic stresses in gyroscopic bodies with applications to air screws caused by particle mass. Report concludes that all modern air screws obey the laws found for plane groups of particles. In particular the two-bladers exert on the shaft a rhythmic gyroscopic torque; the multibladers a steady one; both easily calculable for any given conditions of motion and mass distribution.
Date: 1918
Creator: Zahm, A. F.
Item Type: Refine your search to only Report
open access

Relation of Rib Spacing to Stress in Wing Planes

Description: The stress relations to the fabric and the rib consequent upon a change of spacing between ribs in a wing plane are discussed. Considering the wing plane as a static structure, and ignoring the question of aerodynamic efficiency, it appears that the unit stress in the rib and fabric will remain constant for constant p if the linear dimensions of both rib and fabric are increased alike, viz., if wing and fabric remain geometrically similar. Since the bulge and the structural dimensions remain ge… more
Date: May 1920
Creator: Zahm, A. F.
Item Type: Refine your search to only Report
open access

The six-component wind balance

Description: Dr. Zahm's report is a description of the six-component wind-tunnel balance in use at the Aerodynamic Laboratory, Washington Navy Yard. The description of the balance gives the mechanical details and the method of operation, and is accompanied by line drawings showing the construction of the balance. The balance is of particular interest, as it allows the model to be set up quickly and accurately in roll, pitch, and yaw, without stopping the wind. It is possible to measure automatically, direct… more
Date: 1923
Creator: Zahm, A. F.
Item Type: Refine your search to only Report
open access

Stability Equations for Airship Hulls

Description: In the text are derived simple formulae for determining, directly from the data of wind tunnel tests of a model of an airship hull, what shall be the approximate character of oscillation, in pitch or yaw, of the full-scale airship when slightly disturbed from steady forward motion. (author).
Date: 1926
Creator: Zahm, A. F.
Item Type: Refine your search to only Report
open access

Theories of flow similitude

Description: The laws of comparison of dynamically similar fluid motions are derived by three different methods based on the same principle and yielding the same or equivalent formulas. This report outlines the three current methods of comparing dynamically similar motions, more especially of fluids, initiated respectively by Newton, Stokes (or Helmholtz), and Rayleigh. These three methods, viz., the integral, the differential, and the dimensional, are enough alike to be studied profitably together. They ar… more
Date: May 7, 1928
Creator: Zahm, A. F.
Item Type: Refine your search to only Report
open access

The vector ruling protractor

Description: The theory, structure and working of a vector slide rule is presented in this report. This instrument is used for determining a vector in magnitude and position when given its components and its moment about a point in their plane.
Date: March 1924
Creator: Zahm, A. F.
Item Type: Refine your search to only Report
open access

A Study of Wing Flutter

Description: "Part I describes vibration tests, in a wind tunnel, of simple airfoils and of the tail plane of an M0-1 airplane model; it also describes the air flow about this model. From these tests are drawn inferences as to the cause and cure of aerodynamic wing vibrations. Part II derives stability criteria for wing vibrations in pitch and roll, and gives design rules to obviate instability. Part III shows how to design spars to flex equally under a given wing loading and thereby economically minimize t… more
Date: 1929
Creator: Zahm, A. F. & Bear, R. M.
Item Type: Refine your search to only Report
open access

Airplane stress analysis

Description: Report presents stress analysis of individual components of an airplane. Normal and abnormal loads, sudden loads, simple stresses, indirect simple stresses, resultant unit stress, repetitive and equivalent stress, maximum steady load and stress are considered.
Date: January 1918
Creator: Zahm, A. F. & Crook, L. H.
Item Type: Refine your search to only Report
Back to Top of Screen