Technical Report Archive & Image Library (TRAIL) - 188 Matching Results

Search Results

prev Results: 49 - 72 next
open access

The Excitation of Unstable Perturbations in a Laminar Friction Layer

Description: "With the aid of the method of small oscillations which was used successfully in the investigation of the stability of laminar velocity distributions in the presence of two-dimensional perturbations, the excitation of the unstable perturbations for the Hartree velocity distributions occurring in plane boundary-layer flow for decreasing and increasing pressure is calculated as a supplement to a former report. The results of this investigation are to make a contribution toward calculation of the … more
Date: September 1952
Creator: Pretsch, Joachim
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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
Partner: UNT Libraries Government Documents Department
open access

Experiments on a Tail-Wheel Shimmy

Description: "Model tests on the "running belt" and tests with a full-scale tail wheel were made on a rotating drum as well as on a runway in order to investigate the causes of the undesirable shimmy phenomena frequently occurring on airplane tail wheels, and the means of avoiding them. The small model (scale 1:10) permitted simulation of the mass, moments of inertia, and fuselage stiffness of the airplane and determination of their influence on the shimmy, whereas by means of the larger model with pneumati… more
Date: October 1954
Creator: Dietz, O. & Harling, R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Extension to the Cases of Two Dimensional and Spherically Symmetric Flows of Two Particular Solutions to the Equations of Motion Governing Unsteady Flow in a Gas

Description: "The author previously discovered two interesting particular solutions to the equations of motion describing unsteady flow in a gas confined solely to a one-dimensional duct. These solutions are now extended to cover the more noteworthy cases of central symmetry in two and three dimensions" (p. 1).
Date: June 1952
Creator: Pozzi, Lorenzo
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Extreme Speeds and Thermodynamic States in Supersonic Flight

Description: "The increasing importance of high-speed flow leads to similar problems in various fields of research which are summarized in what follows. Typical of all cases is the conversion of high kinetic energy into extreme thermodynamic states with temperatures of several thousand degrees, frequently connected with dissociation and ionization of the gas involved. There is also a characteristic small sensitivity to the processes discussed in the case of gases of low molecular weight (light gases)" (p. 1… more
Date: April 1958
Creator: Oswatitsch, Klaus
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

The Fatigue Strength of Riveted Joints and Lugs

Description: This report deals with a number of tests on riveted joints and lugs for the primary purpose of comparing the several types of riveted joints and to study the effect of various factors on the fatigue strength of lugs. A check was made to ascertain whether or not an estimate of the fatigue life at a certain loading could be made from the dimensions of the joint and the fatigue data of the unnotched materials. Recommendations are made on the proportioning of joints to obtain better fatigue behavio… more
Date: August 1956
Creator: Schijve, J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Finite Span Wings in Compressible Flow

Description: Equations are developed using the source distribution method for the velocity potential function and pressure on thin wings in steady and unsteady motion. Closed form solutions are given for harmonically oscillating wings of general plan form including the effect of the wing wake. Some useful examples are presented in an appendix for arrow, semielliptical, and hexagonal plan form wings.
Date: September 1956
Creator: Krasilschchikova, E. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Flat Plate Cascades at Supersonic Speed

Description: A brief review of exact two-dimensional supersonic flow theory and Ackeret's linearized theory are first presented. The lift and drag coefficients of a cascade of flat plates are calculated exactly and compared to those obtained using the linearized theory. The forces on the cascade are determined for unsteady inlet flow. The flat plate cascade theory is extended to compute the efficiency of a supersonic propeller with friction and finite blade thickness.
Date: May 1956
Creator: El Badrawy, Rashad M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

A Flat Wing With Sharp Edges in a Supersonic Stream

Description: A basic treatment is given for the approximate solution of the problem of two-dimensional supersonic flow past a thin wing at small angles of attack. The pressure distribution at the surface, the lifting force, and the wave drag are determined.
Date: March 1956
Creator: Donov, A. E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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
Partner: UNT Libraries Government Documents Department
open access

Flow of Gas Through Turbine Lattices

Description: This report is concerned with fluid mechanics of two-dimensional cascades, particularly turbine cascades. Methods of solving the incompressible ideal flow in cascades are presented. The causes and the order of magnitude of the two-dimensional losses at subsonic velocities are discussed. Methods are presented for estimating the flow and losses at high subsonic velocities. Transonic and supersonic flows in lattices are then analyzed. Some three-dimensional features of the flow in turbines are not… more
Date: May 1956
Creator: Deich, M. E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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
Partner: UNT Libraries Government Documents Department
open access

Formation of a Vortex at the Edge of a Plate

Description: The flow about the plate of infinite width may be represented as a potential flow with discontinuity surfaces which extend from the plate edges. On the basis of a similitude requirement one succeeds in finding a solution of this problem for the plate of infinite width which is correct for the very beginning of the motion of the fluid. Starting from this solution, the further development of the vortex distribution and shape of the surface are observed in the case of a plate of finite width.
Date: March 1956
Creator: Anton, Leo
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Free Convection Under the Conditions of the Internal Problem

Description: Convection is called free is the stresses (including the normal pressure) to which the fluid is subjected at its boundaries do not perform mechanical work, that is, if all the boundaries of the fluid are stationary. The case where this is not true is termed forced convection. It corresponds to the action on the fluid of some mechanical suction pumping the fluid.
Date: April 1958
Creator: Ostroumov, G. A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Friction and Wear

Description: From the practical point of view, this analysis shows that each problem of friction or wear requires its particular solution. There is no universal solution; one or other of the factors predominates and defines the choice of the solution. In certain cases, copper alloys of great thermal conductivity are preferred; in others, plastics abundantly supplied with water. Sometimes, soft antifriction metals are desirable to distribute the load; at other times, hard metals with high resistance to abras… more
Date: March 1952
Creator: Pomey, Jacques
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

From Linear Mechanics to Nonlinear Mechanics

Description: Consideration is given to the techniques used in telecommunication where a nonlinear system (the modulator) results in a linear transposition of a signal. It is then shown that a similar method permits linearization of electromechanical devices or nonlinear mechanical devices. A sweep function plays the same role as the carrier wave in radio-electricity. The linearizations of certain nonlinear functionals are presented.
Date: October 1955
Creator: Loeb, Julien
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

The Gas Kinetics of Very High Flight Speeds

Description: The aerodynamic forces on bodies of arbitrary shape were investigated under conditions such that the mean free path of the air molecule is greater than the dimensions of the body. Air pressures and friction forces were calculated from gas kinetic theory for surfaces facing both toward and away from the air stream at any angle. Air forces for an atmosphere of definite composition (molecular hydrogen) were calculated as a function of the flight velocity.
Date: May 1950
Creator: Sänger, Eugen
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

General Solutions of Optimum Problems in Nonstationary Flight

Description: "A general method concerning optimum problems in nonstationary flight is developed and discussed. Best flight techniques are determined for the following conditions: climb with minimum time, climb with minimum fuel consumption, steepest climb, descending and gliding flight with maximum time or with maximum distance. Optimum distributions of speed with altitude are derived assuming constant airplane weight and neglecting curvatures and squares of path inclination in the projection of the equatio… more
Date: October 1955
Creator: Miele, Angelo
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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
Partner: UNT Libraries Government Documents Department
open access

Graphical Determination of Wall Temperatures for Heat Transfers Through Walls of Arbitrary Shape

Description: "A graphical method is given which permits determining of the temperature distribution during heat transfer in arbitrarily shaped walls. Three examples show the application of the method. The further development of heat engines depends to a great extent on the control of the thermal stresses in the walls" (p. 1).
Date: April 1950
Creator: Lutz, Otto
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Heat Transfer by Free Convection From Horizontal Cylinders in Diatomic Gases

Description: "The case of the horizontal cylinder is of particular importance in the study of heat transfer by free convection for the following reasons: In the first place, next to the rectangular plate it represents the simplest two-dimensional case; and second, a very wide range of measurements is possible, from the finest electrically heated glow lamp wires to pipes heated by liquids or gases flowing through them" (p. 1).
Date: November 1954
Creator: Hermann, R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
Back to Top of Screen