UNT Libraries Government Documents Department - 37 Matching Results

Search Results

Results: 1 - 24 next
open access

Basic Differential Equations in General Theory of Elastic Shells

Description: "The shell shall be considered as a three-dimensional continuous medium; for the coordinate surface, the middle surface of the shell shall be assumed parallel to the bounding surfaces. Let alpha and beta be the curvilinear orthogonal coordinates of this surface, coinciding with the lines of principal curvatures, and gamma the distance along the normal from the point (alpha,beta) of the coordinate surface to any point (alpha, beta, gamma) of the shell" (p. 1).
Date: February 1951
Creator: Vlasov, V. S.
Item Type: Refine your search to only Report
open access

Behavior of Fast Moving Flow of Compressible Gas in Cylindrical Pipe in Presence of Cooling

Description: For compressible flow with friction in a cylindrical pipe the momentum, continuity, and heat-transfer equations are examined to determine whether an increase in Mach number ("thermal" Laval nozzle) is obtainable through heat conduction from the gas through the pipe walls. The analysis is based on the assumption that the wall temperature is negligibly small in comparison with the stagnation temperature of the gas. The analysis leads to a negative result. When the gas cooling is increased by also… more
Date: September 1951
Creator: Varshavsky, G. A.
Item Type: Refine your search to only Report
open access

Calculation of the Bending Stresses in Helicopter Rotor Blades

Description: A comparatively rapid method is presented for determining theoretically the bending stresses of helicopter rotor blades in forward flight. The method is based on the analysis of the properties of a vibrating beam, and its uniqueness lies in the simple solution of the differential equation which governs the motion of the bent blades.
Date: March 1951
Creator: de Guillenchmidt, P.
Item Type: Refine your search to only Report
open access

Concerning the Flow About Ring-Shaped Cowlings Part 2: Annular Bodies of Infinite Length With Circulation for Smooth Entrance

Description: The investigations carried out in a previous report (NACA TM 1325) concerning the flow about ring-shaped cowlings were extended by taking a circulation about the cowling into consideration. The present second report treats bodies of infinite length with approximately smooth entrance. The circulation was caused by distributing vortex rings of constant density over a stream surface extending to infinity. Furthermore, the influence of a hub body on such cowlings was dealt with.
Date: November 1951
Creator: Küchemann, Dietrich & Weber, Johanna
Item Type: Refine your search to only Report
open access

Concerning the Flow About Ring-Shaped Cowlings Part 6: Further Measurements on Inlet Devices

Description: "The present report presents as a supplement to the fourth report (available as ATI 5045, Air Materiel Command) in the series of investigations concerning the flow about ring-shaped cowlings further wind-tunnel measurements on inlet devices which are to show the influence of the radius of the nose of the cowling on the flow conditions. Moreover, a simple rule for the design of such arrangements, containing a hub in the interior, is suggested" (p. 1).
Date: December 1951
Creator: Küchemann, Dietrich & Weber, Johanna
Item Type: Refine your search to only Report
open access

Correction Factors for Wind Tunnels of Elliptic Section With Partly Open and Partly Closed Test Section

Description: Jet boundary corrections for partly open and partly closed elliptical wind tunnels for the cases of one and two solid wall segments are presented. Also presented are the combinations of model span and extent of the solid portion of the tunnel wall for which the average correction factor is zero.
Date: March 1951
Creator: Riegels, Fritz W.
Item Type: Refine your search to only Report
open access

Critical Velocities of Ultracentrifuges

Description: The Euler equations for the rotation of a solid body are applied to the problem of the motion of ultracentrifuges. Particular attention is paid to the problem of the passage of an ultracentrifuge rotor through the critical velocity. The factors that affect the passage of rotors through the critical point are stressed.
Date: March 1951
Creator: Sokolov, V. I.
Item Type: Refine your search to only Report
open access

Deplacement Effect of the Laminar Boundary Layer and the Pressure Drag

Description: The displacement effect of the boundary layer on the outer frictionless flow is discussed for both steady and unsteady flows. The analysis is restricted to cases in which the potential flow pressure distribution remains valid for the boundary-layer calculation. Formulas are given for the dependence of the pressure drag, friction drag, and total drag of circular cylinders on the time from the start of motion for cases in which the velocity varies as a power of the time. Formulas for the location… more
Date: October 1951
Creator: Görtler, H.
Item Type: Refine your search to only Report
open access

Exhaust Turbine and Jet Propulsion Systems

Description: DVL experimental and analytical work on the cooling of turbine blades by using ram air as the working fluid over a sector or sectors of the turbine annulus area is summarized. The subsonic performance of ram-jet, turbo-jet, and turbine-propeller engines with both constant pressure and pulsating-flow combustion is investigated. Comparison is made with the performance of a reciprocating engine and the advantages of the gas turbine and jet-propulsion engines are analyzed. Nacelle installation meth… more
Date: April 1951
Creator: Leist, Karl & Knörnschild, Eugen
Item Type: Refine your search to only Report
open access

Flight Performance of a Jet Power Plant, 3, operating characteristics of a jet power plant as a function of altitude

Description: The performance of a jet power plant consisting of a compressor and a turbine is determined by the characteristic curves of these component parts and is controllable by the characteristics of the compressor and the turbine in relation to each other. The normal. output, overload, and throttled load of the Jet power plant are obtained on the basis of assumed straight-line characteristics.
Date: May 1951
Creator: Weinig, F.
Item Type: Refine your search to only Report
open access

The Flow of Gases in Narrow Channels

Description: Measurements were made of the flow of gases through various narrow channels a few microns wide at average pressures from 0.00003 to 40 cm. Hg. The flow rate, defined as the product of pressure and volume rate of flow at unit pressure difference, first decreased linearly with decrease in mean pressure in the channel, in agreement with laminar-flow theory, reached a minimum when the mean path length was approximately equal to the channel width, and then increased to a constant value. The product … more
Date: August 1951
Creator: Rasmussen, R. E. H.
Item Type: Refine your search to only Report
open access

Generalization of Joukowski formula to an airfoil of a cascade in compressible gas stream with subsonic velocities

Description: It is shown that the ordinary Joukowski formula for lift force of cascade blades in incompressible flow can be applied to the case of subsonic compressible flow with sufficient accuracy, provided that the density in the formula is taken as the arithmetic mean of the densities far ahead of and behind the cascade.
Date: September 1951
Creator: Loitsianskii, L. G.
Item Type: Refine your search to only Report
open access

Influence of Static Longitudinal Stability on the Behavior of Airplanes in Gusts

Description: The equations of motion for an airplane penetrating a gust are derived using a few simplifying assumptions. Calculations of loads for different static longitudinal stability on two German airplane models, HC 45 and HS 122, are compared with flight tests. Good agreement is obtained between the trend of the flight tests and the calculated values; however no absolute comparison was possible between the flight tests and calculations.
Date: November 1951
Creator: Hoene, H.
Item Type: Refine your search to only Report
open access

Investigations on Wings With and Without Sweepback at High Subsonic Speeds

Description: Drag tests at zero lift have been made at Mach numbers from 0.7 to approximately 0.95 in the high speed wind tunnel of the Institute of Aerodynamics, ETH, Zurich, on a group of untapered wings of aspect ratio 3.25, having sweep angles of 0 degree and 35 degrees. For each sweep angle, a series of geometrically similar models was tested at a constant Reynolds number to provide a verification of computed tunnel blocking corrections. Tests were also made for wings having thickness ratios of 0.09 an… more
Date: November 1951
Creator: Ackeret, Jakob; Degen, Max & Rott, Nikolaus
Item Type: Refine your search to only Report
open access

Lateral Control by Spoilers at the DVL

Description: "The present report describes the development of spoiler control at the DVL from the end of 1936 until the beginning of 1939. The authors are fully aware that the present report also forms only a contribution to the problem of spoiler control and offers at best a possibility of extrapolation regarding the behavior of the control in modern airplanes. A modern airplane (Me 109) is being reconstructed for conversion to spoiler control" (p. 1).
Date: August 1951
Creator: Kramer, Max; Zobel, Theodor W. & Esche, C. G.
Item Type: Refine your search to only Report
open access

Method of Successive Approximations for the Solution of Certain Problems in Aerodynamics

Description: A method of successive approximations for the solution of problems in the fields of diffusion, boundary-layer flow, and heat-transfer is illustrated by solving problems in each of these fields. In most of the examples, the approximate solutions are compared with known accurate solutions and the agreement is shown to be good.
Date: April 1951
Creator: Shvets, M. E.
Item Type: Refine your search to only Report
open access

On Ionization and Luminescence in Flames

Description: An explanation based upon reaction kinetics is presented to account for the deviation of measured ionization levels obtained from reflection experiments from the values computed assuming chemical equilibrium. The heat transfer to the unburned fuel is also considered.
Date: April 1951
Creator: Sänger, E.; Goercke, P. & Bredt, I.
Item Type: Refine your search to only Report
open access

On Motion of Fluid in Boundary Layer Near Line of Intersection of Two Planes

Description: From Summary: "In the paper "The Mutual Interference of Boundary Layers," the authors investigated the problem of the interference of two planes intersecting at right angles on the boundary layers formed by the motion of fluid along the line of intersection of these planes. In the present paper, the results of the preceding one are generalized to the case of planes intersecting at any angle. The motion of a fluid in an angle less than 180 degrees is discussed and the enlargement of the boundary… more
Date: November 1951
Creator: Loitsianskii, L. G. & Bolshakov, V. P.
Item Type: Refine your search to only Report
open access

On Stability and Turbulence of Fluid Flows

Description: This investigation is divided into two parts, the treatment of the stability problem of fluid flows on the one hand, and that of the turbulent motion on the other. The first part summarizes all previous investigations under a unified point of view, that is, sets up as generally as possible the conditions under which a profile possesses unstable or stable characteristics, and indicates the methods for solution of the stability equation for any arbitrary velocity profile and for calculation of th… more
Date: June 1951
Creator: Heisenberg, Werner
Item Type: Refine your search to only Report
open access

On the recording of turbulent longitudinal and transverse fluctuations

Description: "A thorough understanding of the turbulent flow movements cannot be arrived at from investigations of the temporal mean values of the flows alone. Study of the fluctuation phenomena themselves is indispensable. Thus turbulence research entered a new promising stage when investigators started performing fluctuation measurements and basing theories on those measurements" (p. 1).
Date: August 1951
Creator: Reichardt, H.
Item Type: Refine your search to only Report
open access

On the Theory of Combustion of Initially Unmixed Gases

Description: The chemical reaction of two substances (fuel and oxygen) accompanied by the formation of new substances of the products of combustion and the liberation of heat is considered. General equations are provided as well as an analysis of the equation and the distribution of products of the reaction.
Date: June 1951
Creator: Zeldovich, Y. B.
Item Type: Refine your search to only Report
open access

On the Theory of Thin and Thin-Walled Rods

Description: Through the work of V. Z. Vlasov a theory of thin-walled rods has been established that is widely applicable in practice. This theory was extended by A. A. Umanski to thin-walled rods of closed profile section. This report attempts to construct a theory of thin-walled rods, including the classical theory of deformation of thin rods, by making use of a kinematic assumption.
Date: October 1951
Creator: Dzhanelidze, G. Y.
Item Type: Refine your search to only Report
open access

On the Turbulent Friction Layer for Rising Pressure

Description: Among the information presented are included displacement, momentum, and kinetic energy thicknesses, shearing stress distributions across boundary layer, and surface friction coefficients. The Gruschwitz method and its modifications are examined and tested. An energy theorem for the turbulent boundary layer is introduced and discussed but does not lead to a method for the prediction of the behavior of the turbulent boundary layer because relations for the shearing stress and the surface frictio… more
Date: October 1951
Creator: Wieghardt, K. & Tillmann, W.
Item Type: Refine your search to only Report
Back to Top of Screen