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  Partner: UNT Libraries Government Documents Department
 Decade: 1940-1949
 Collection: Technical Report Archive and Image Library
Investigation of the Behavior of Thin-Walled Panels with Cutouts

Investigation of the Behavior of Thin-Walled Panels with Cutouts

Date: September 1, 1946
Creator: Podorozhny, A. A.
Description: The present paper deals with the computation and methods of reinforcement of stiffened panels with cutouts under bending loads such as are applied to the sides of a fuselage. A comparison is maade between the computed and test results. Results are presented of tests on panels with cutouts under tensile and compressive loads.
Contributing Partner: UNT Libraries Government Documents Department
Investigations of Compression Shocks and Boundary Layers in Gases Moving at High Speed

Investigations of Compression Shocks and Boundary Layers in Gases Moving at High Speed

Date: January 1, 1947
Creator: Ackeret, J.; Feldmann, F. & Rott, N.
Description: The mutual influences of compression shocks and friction boundary layers were investigated by means of high speed wind tunnels.Schlieren optics provided a clear picture of the flow phenomena and were used for determining the location of the compression shocks, measurement of shock angles, and also for Mach angles. Pressure measurement and humidity measurements were also taken into consideration.Results along with a mathematical model are described.
Contributing Partner: UNT Libraries Government Documents Department
The Calculation of Compressible Flows with Local Regions of Supersonic Velocity

The Calculation of Compressible Flows with Local Regions of Supersonic Velocity

Date: March 1, 1947
Creator: Goethert, B. & Kawalki, K. H.
Description: This report addresses a method for the approximate calculation of compressible flows about profiles with local regions of supersonic velocity. The flow around a slender profile is treated as an example.
Contributing Partner: UNT Libraries Government Documents Department
Drag Reduction by Suction of the Boundary Layer Separated Behind Shock Wave Formation at High Mach Numbers

Drag Reduction by Suction of the Boundary Layer Separated Behind Shock Wave Formation at High Mach Numbers

Date: July 1, 1947
Creator: Regenscheit, B.
Description: With an approach of the velocity of flight of a ship to the velocity of sound, there occurs a considerable increase of the drag. The reason for this must be found in the boundary layer separation caused by formation of shock waves. It will be endeavored to reduce the drag increase by suction of the boundary layer. Experimental results showed that drag increase may be considerably reduced by this method. It was, also, observed that, by suction, the position of shock waves can be altered to a considerable extent.
Contributing Partner: UNT Libraries Government Documents Department
Temperatures and Stresses on Hollow Blades For Gas Turbines

Temperatures and Stresses on Hollow Blades For Gas Turbines

Date: September 1, 1947
Creator: Pollmann, Erich
Description: The present treatise reports on theoretical investigations and test-stand measurements which were carried out in the BMW Flugmotoren GMbH in developing the hollow blade for exhaust gas turbines. As an introduction the temperature variation and the stress on a turbine blade for a gas temperature of 900 degrees and circumferential velocities of 600 meters per second are discussed. The assumptions onthe heat transfer coefficients at the blade profile are supported by tests on an electrically heated blade model. The temperature distribution in the cross section of a blade Is thoroughly investigated and the temperature field determined for a special case. A method for calculation of the thermal stresses in turbine blades for a given temperature distribution is indicated. The effect of the heat radiation on the blade temperature also is dealt with. Test-stand experiments on turbine blades are evaluated, particularly with respect to temperature distribution in the cross section; maximum and minimum temperature in the cross section are ascertained. Finally, the application of the hollow blade for a stationary gas turbine is investigated. Starting from a setup for 550 C gas temperature the improvement of the thermal efficiency and the fuel consumption are considered as well as the increase of ...
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Gas Jets

Gas Jets

Date: August 1, 1944
Creator: Chaplygin, S.
Description: A brief summary of the contents of this paper is presented here. In part I the differential equations of the problem of a gas flow in two dimensions is derived and the particular integrals by which the problem on jets is solved are given. Use is made of the same independent variables as Molenbroek used, but it is found to be more suitable to consider other functions. The stream function and velocity potential corresponding to the problem are given in the form of series. The investigation on the convergence of these series in connection with certain properties of the functions entering them forms the subject of part II. In part III the problem of the outflow of a gas from an infinite vessel with plane walls is solved. In part IV the impact of a gas jet on a plate is considered and the limiting case where the jet expands to infinity changing into a gas flow is taken up in more detail. This also solved the equivalent problem of the resistance of a gaseous medium to the motion of a plate. Finally, in part V, an approximate method is presented that permits a simpler solution of the problem of ...
Contributing Partner: UNT Libraries Government Documents Department
Investigations on Experimental Impellers for Axial Blowers

Investigations on Experimental Impellers for Axial Blowers

Date: April 1, 1947
Creator: Encke, W.
Description: A selection of measurements obtained on experimental impellers for axial blowers will be reported. In addition to characteristic curves plotted for low and for high peripheral velocities, proportions and blade sections for six different blower models and remarks on the design of blowers will be presented.
Contributing Partner: UNT Libraries Government Documents Department
Investigation of Flow in a Centrifugal Pump

Investigation of Flow in a Centrifugal Pump

Date: July 1, 1946
Creator: Fischer, Karl
Description: The investigation of the flow in a centrifugal pump indicated that the flow patterns in frictional fluid are fundamentally different from those in frictionless fluid. In particular, the dead air space adhering to the section side undoubtedly causes a reduction of the theoretically possible delivery head. The velocity distribution over a parallel circle is also subjected to a noticeable change as a result of the incomplete filling of the passages. The relative velocity on the pressure side of the vane, which for passages completely filled with active flow would differ little from zero even at comparatively lower than normal delivery volume, is increased, so that no rapid reverse flow occurs on the pressure side of the vane even for smaller delivery volume. It was established, further, that the flow ceases to be stationary for very small quantities of water. The inflow to the impeller can be regarded as radial for the operating range an question. The velocity triangles at the exit are subjected to a significant alteration in shape ae a result of the increased peripheral velocity, which may be of particular importance in the determination of the guide vane entrance angle.
Contributing Partner: UNT Libraries Government Documents Department
The Flow Through Axial Turbine Stages of Large Radial Blade Length

The Flow Through Axial Turbine Stages of Large Radial Blade Length

Date: April 1, 1947
Creator: Eckert & Korbacher
Description: A calulation of the flow in turbine blading is reported that includes the calculation of effect of centrifugal force. Frictional losses on the stator blades and rotor blades are allowed.
Contributing Partner: UNT Libraries Government Documents Department
Gas-Dynamic Investigations of the Pulse-Jet Tube, Parts 1 and 2

Gas-Dynamic Investigations of the Pulse-Jet Tube, Parts 1 and 2

Date: February 1, 1947
Creator: Shultz-Grunow, F.
Description: Based upon a simplified representation of the mode of operation of the pulse-jet tube, the effect of the influences mentioned in the title were investigated and it will be shown that, for a jet tube with a fccmndesigned to be aerodynamically favorable, the ability to operate is at least questionable. By taking into account the course of the development of pressure by combustion, a new insight has been obtained into the processes of motion within the jet tube, an insight that explains a number of empirical observations, namely: certain particulars of the sequence of pressure variations; the existence of an optimum valve-opening ratio; the occurrence of an intrusion of air; and the existence of a flight speed above lrhichthe jet tube ceases to operate. At too great an opening ratio or at too great a flight s-peed, the continuous flow through the tube is too predominant over the oscilla~ory process to perinitthe occurrence of an explosion powerful enough to maintain continuous operation. Certain possible means of making the operation of the jet tube more independent of the flight speed and of reducing the flow losses were proposed and discussed.
Contributing Partner: UNT Libraries Government Documents Department
Some Basic Laws of Isotropic Turbulent Flow

Some Basic Laws of Isotropic Turbulent Flow

Date: September 1, 1945
Creator: Loitsianskii, L. G.
Description: An Investigation is made of the diffusion of artificially produced turbulence behind screens or other turbulence producers. The method is based on the author's concept of disturbance moment as a certain theoretically well-founded measure of turbulent disturbances.
Contributing Partner: UNT Libraries Government Documents Department
Theory of Wings in Nonstationary Flow

Theory of Wings in Nonstationary Flow

Date: June 1, 1947
Creator: Nekrasov, A. I.
Description: This paper gives an overview of equations for vibration and flutter affecting airplane wings in nonstationary flow.
Contributing Partner: UNT Libraries Government Documents Department
Possibilities of Reducing the Length of Axial Superchargers for Aircraft Motors

Possibilities of Reducing the Length of Axial Superchargers for Aircraft Motors

Date: January 1, 1947
Creator: Eckert, B.
Description: Axial blowers are gaining importance as aircraft engine superchargers. However, the pressure head obtainable per stage is small. Due to the necessary great number of stages, the physical length of the blower becomes too great for an airworthy device. This report discusses several types of construction that permit a reduction in the length of the blower.
Contributing Partner: UNT Libraries Government Documents Department
Wind-Tunnel Measurements on the Henschel Missile "Zitterrochen" in Subsonic and Supersonic Velocities

Wind-Tunnel Measurements on the Henschel Missile "Zitterrochen" in Subsonic and Supersonic Velocities

Date: April 1, 1948
Creator: Weber & Kehl
Description: At the request of the Henschel Aircraft Works. A. G. Berlin. three models of the missile "Zitterrochen" were investigated at subsonic velocities.(open jet 215-millimeter diameter) and at supersonic velocities (open jet 110 by 130 millimeters) in order to determine the effect of various wing forms on the air forces and moments. Three-component measurements were taken, and one model was also investigated with deflected control plates.
Contributing Partner: UNT Libraries Government Documents Department
Recommendations for numerical solution of reinforced-panel and fuselage-ring problems

Recommendations for numerical solution of reinforced-panel and fuselage-ring problems

Date: January 1, 1949
Creator: Hoff, N J & Libby, Paul A
Description: Procedures are recommended for solving the equations of equilibrium of reinforced panels and isolated fuselage rings as represented by the external loads and the operations table established according to Southwell's method. From the solution of these equations the stress distribution can be easily determined. The method of systematic relaxations, the matrix-calculus method, and several other methods applicable in special cases are discussed. Definite recommendations are made for obtaining the solution of reinforced-panel problems which are generally designated as shear lag problems. The procedures recommended are demonstrated in the analysis of a number of panels. In the case of fuselage rings it is not possible to make definite recommendations for the solution of the equilibrium equations for all rings and loadings. However, suggestions based on the latest experience are made and demonstrated on several rings.
Contributing Partner: UNT Libraries Government Documents Department
Plastic buckling of a rectangular plate under edge thrusts

Plastic buckling of a rectangular plate under edge thrusts

Date: January 1, 1949
Creator: Handelman, G H & Prager, W
Description: The fundamental equations for the plastic buckling of a rectangular plate under edge thrusts are developed on the basis of a new set of stress-strain relations for the behavior of a metal in the plastic range. These relations are derived for buckling from a state of uniform compression. The fundamental equation for the buckling of a simply compressed plate together with typical boundary conditions is then developed and the results are applied to calculating the buckling loads of a thin strip, a simply supported plate, and a cruciform section. Comparisons with the theories of Timoshenko and Ilyushin are made. Finally, an energy method is given which can be used for finding approximate values of the critical load.
Contributing Partner: UNT Libraries Government Documents Department
Investigations of effects of surface temperature and single roughness elements on boundary-layer transition

Investigations of effects of surface temperature and single roughness elements on boundary-layer transition

Date: January 1, 1947
Creator: Liepmann, Hans W & Fila, Gertrude H
Description: The laminar boundary layer and the position of the transition point were investigated on a heated flat plate. It was found that the Reynolds number of transition decreased as the temperature of the plate is increased. It is shown from simple qualitative analytical considerations that the effect of variable viscosity in the boundary layer due to the temperature difference produces a velocity profile with an inflection point if the wall temperature is higher than the free-stream temperature. This profile is confirmed by measurements. The instability of inflection-point profiles is discussed. Studies of the flow in the wake of large, two-dimensional roughness elements are presented. It is shown that a boundary-layer can separate and reattach itself to the wall without having transition take place.
Contributing Partner: UNT Libraries Government Documents Department
Adaptor for measuring principal strains with Tuckerman strain gage

Adaptor for measuring principal strains with Tuckerman strain gage

Date: January 1, 1943
Creator: Mcpherson, A E
Description: An adapter is described which uses three Tuckerman optical strain gages to measure the displacement of the three vortices of an equilateral triangle along lines 120 degrees apart. These displacements are substituted in well-known equations in order to compute the magnitude and direction of the principal strains. Tests of the adaptor indicate that principal strains over a gage length of 1.42 inch may be measured with a systematic error not exceeding 4 percent and a mean observational error of the order of + or minus 0.000006. The maximum observed error in strain was of the order of 0.00006. The directions of principal strains for unidirectional stress were measured with the adaptor with an average error of the order of 1 degree.
Contributing Partner: UNT Libraries Government Documents Department
The Motion of Massive Particles Through Solid Matter

The Motion of Massive Particles Through Solid Matter

Date: April 27, 1944
Creator: Seitz, Frederick, 1911-2008
Description: Report concerning the behavior of atoms dislodged from their positions in solid constituents by neutrons during the transition from high energy to thermal energy.
Contributing Partner: UNT Libraries Government Documents Department
The Influence of Infection on the Hematological Effects and Mortality Following Mid-Lethal X-Radiation

The Influence of Infection on the Hematological Effects and Mortality Following Mid-Lethal X-Radiation

Date: August 18, 1949
Creator: University of Rochester. Atomic Energy Project.
Description: Report describing the blood cultures of fifty-four dogs that were exposed mid-lethal whole body x-radiation.
Contributing Partner: UNT Libraries Government Documents Department
Stress distribution in and equivalent width of flanges of wide, thin-wall steel beams

Stress distribution in and equivalent width of flanges of wide, thin-wall steel beams

Date: January 1, 1940
Creator: Winter, George
Description: The use of different forms of wide-flange, thin-wall steel beams is becoming increasingly widespread. Part of the information necessary for a national design of such members is the knowledge of the stress distribution in and the equivalent width of the flanges of such beams. This problem is analyzed in this paper on the basis of the theory of plane stress. As a result, tables and curves are given from which the equivalent width of any given beam can be read directly for use in practical design. An investigation is given of the limitations of this analysis due to the fact that extremely wide and thin flanges tend to curve out of their plane toward the neutral axis. A summary of test data confirms very satisfactorily the analytical results.
Contributing Partner: UNT Libraries Government Documents Department
Determination of rate, area, and distribution of impingement of waterdrops on various airfoils from trajectories obtained on the differential analyzer

Determination of rate, area, and distribution of impingement of waterdrops on various airfoils from trajectories obtained on the differential analyzer

Date: February 16, 1949
Creator: Guibert, A. G.; Janssen, E. & Robbins, W. M.
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Moments of cambered round bodies

Moments of cambered round bodies

Date: August 1, 1949
Creator: Kempf, Gunther
Description: Results are presented for the moments and position of force centers of a series of cambered round bodies derived from a torpedo-like body of revolution. The effects of placing fins on the rear of the body of revolution are also included.
Contributing Partner: UNT Libraries Government Documents Department
Shear Lag in a Plywood Sheet-Stringer Combination Used for the Chord Member of a Box Beam

Shear Lag in a Plywood Sheet-Stringer Combination Used for the Chord Member of a Box Beam

Date: March 1, 1948
Creator: Borsari, Palamede & Yu, Ai-Ting
Description: Theoretical and experimental investigations were made of the distribution of strains in a plywood sheet-stringer combination used as the chord member of a box beam acted upon by bending loads. The theoretical solution was obtained with the help of the principle of minimum potential energy and certain simplifying assumptions. Strain measurements were made on a build-up box beam by means of electrical-resistance strain gages connected with strain indicators. A very satisfactory agreement between the theoretical and experimental strains was obtained.
Contributing Partner: UNT Libraries Government Documents Department
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