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The Mass Transfer of Single, Solid Uranium Spheres to Flowing Molten Cadmium in Laminar and Turbulent Flow

Description: From Summary and Abstract: "In this study, a 1/2-inch diameter uranium sphere was used and molten cadmium was pumped past the test spheres at different flow rates. Mass transfer coefficients were determined from weight losses of the test spheres."
Date: September 1965
Creator: Traylor, E. Dean
Partner: UNT Libraries Government Documents Department

Apparatus for measurements of time and space correlation

Description: The report describes a brief review is made of improvements to an experimental apparatus for time and space correlation designed for study of turbulence. Included is a description of the control of the measurements and a few particular applications.
Date: April 1955
Creator: Favre, Alexandre; Gaviglio, J & Dumas, R
Partner: UNT Libraries Government Documents Department

Measurements of intensity and scale of wind-tunnel turbulence and their relation to the critical Reynolds number of spheres

Description: The investigation of wind-tunnel turbulence, conducted at the National Bureau of Standards with the cooperation of the National Advisory Committee for Aeronautics, has been extended to include a new variable, namely, the scale of the turbulence. This report presents the results of a study of this new variable together with the intensity of the turbulence, and the effect of both on the critical Reynolds number of spheres.
Date: 1937
Creator: Dryden, Hugh L.; Schubauer, G. B.; Mock, W. C., Jr. & Skramstad, H. K.
Partner: UNT Libraries Government Documents Department

Recent results of turbulence research

Description: The first sections of this report deal with two prominent questions, namely the origin of turbulence and the characteristics of turbulent currents. In the third section conclusions are drawn for the flow along a rough wall, whereby an important relation for the velocity distribution is revealed. The principles are also applied to straight rough and smooth tubes.
Date: August 1933
Creator: Prandtl, L.
Partner: UNT Libraries Government Documents Department

The use of wind tunnels to predict flight buffet loads

Description: From Summary: "Methods and techniques developed for the study of buffeting by use of wind-tunnel models are described. Requirements on model damping and frequency characteristics, the model support system, and the effects of wind-tunnel turbulence on buffet tests are outlined. The results are shown of a recent comparison of buffet loads measured on a research airplane with thin unswept wings and on two different models of the airplane in two different wind tunnels."
Date: June 10, 1957
Creator: Davis, Don D., Jr. & Huston, Wilber B.
Partner: UNT Libraries Government Documents Department

An analysis of the indications of the University of Chicago airborne turbulence indicator in gusty air

Description: From Introduction: "The present report has been prepared to discuss the indications obtained from the University of Chicago turbulence indicator in relation to simultaneous measurement of atmospheric gustiness made by the NACA, which are summarized herein."
Date: August 1946
Creator: Pratt, K G
Partner: UNT Libraries Government Documents Department

Turbulent flow

Description: Report presenting some information and potential areas of study of turbulent flow and turbulence.
Date: October 1927
Creator: Prandtl, L.
Partner: UNT Libraries Government Documents Department

Effect of stabilizing forces on turbulence

Description: The appearance of expressed discontinuity layers in the free atmosphere, where a warm air mass flows over a cold mass without perceptible intermingling forms the basis of the present report. In these experiments an air stream is to be blown between a water-cooled and a vapor-heated plate. According to what preceded it is anticipated that the exchange will be enhanced. Because these experiments had to be made at relatively low air speeds so as to let the lifting forces become effective, it first required a study of the test methods, and so we have not yet proceeded beyond the preliminary tests on the most suitable hot-wire connections and thermocouples for recording speed and temperature.
Date: June 1931
Creator: Prandtl, L.
Partner: UNT Libraries Government Documents Department

The variation of atmospheric turbulence with altitude and its effect on airplane gust loads

Description: Report presenting information on the amount and relative intensity of atmospheric turbulence for altitudes up to 60,000 as obtained by airplanes and balloon-borne instruments. Analysis of the data obtained indicated that there are substantial reductions in turbulence at higher altitudes in the weather conditions measured in the tests. Results regarding gust distributions, including non-thunderstorm turbulence, thunderstorm turbulence, total gust distributions, and a comparison of gusts are also provided.
Date: November 9, 1953
Creator: McDougal, Robert L.; Coleman, Thomas L. & Smith, Philip L.
Partner: UNT Libraries Government Documents Department

Airspeed fluctuations as a measure of atmospheric turbulence

Description: From Introduction: "Increments in structural loads due to atmospheric turbulence can be accurately expressed in terms of flight speed and effective gust velocities (reference 4). Data from which the effective gust velocities could be computed were also obtained during the flights of the XC-35 airplane. These data have been used to determine the significance of the fluctuations in the pilot's indicated-airspeed readings in relation to structural loads to due to atmospheric turbulence."
Date: July 1945
Creator: Tolefson, H B
Partner: UNT Libraries Government Documents Department

Correlation of data on the statistical theory of turbulence

Description: The statistical theory of turbulence affords an excellent medium for representing the kinematic conditions in turbulent flow and also serves as a valuable aid to exact experimental research. But it is still not developed enough for solving dynamic processes. Even in the simplest case of isotropic turbulence the calculation of the correlation curve or of the decrement of turbulence invariably reaches a point where clear-cut assumptions, such as omission of the inertia terms, or, earlier, mixing length assumptions or even merely general dimensional considerations, must be made.
Date: March 1942
Creator: Wieghardt, K.
Partner: UNT Libraries Government Documents Department

Some Basic Laws of Isotropic Turbulent Flow

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.
Date: September 1945
Creator: Loitsianskii, L. G.
Partner: UNT Libraries Government Documents Department

Preliminary Investigation in the NACA Low-Turbulence Tunnel of Low-Drag Airfoil Sections Suitable for Admitting Air at the Leading Edge

Description: From Summary: "An investigation was carried out in the NACA low-turbulence tunnel to develop low-drag airfoil sections suitable for admitting air at the leading edge. A thickness distribution having the desired type of pressure distribution was found from tests of a flexible model. Other airfoil shapes were derived from this original shape by varying the thickness, the camper, the leading-edge radius, and the size of the leading-edge opening. Data are presented giving the characteristics of the airfoil shapes in the range of lift coefficients for high-speed and cruising flight."
Date: July 1942
Creator: von Doenhoff, Albert E. & Horton, Elmer A.
Partner: UNT Libraries Government Documents Department

Effect of spanwise variations in gust intensity on the lift due to atmospheric turbulence

Description: The effect of spanwise variations in gust intensity on the power spectrum directly due to atmospheric turbulence is calculated for several analytic approximations to the correlation function or power spectra of atmospheric turbulence, for several spanwise weighing functions (span loadings), and for various angles of sweepback.
Date: April 1957
Creator: Diederich, Franklin W. & Drischler, Joseph A.
Partner: UNT Libraries Government Documents Department

Spark ignition of flowing gases III : effect of turbulence promoter on energy required to ignite a propane-air mixture

Description: Report presenting an investigation to determine the effect of turbulence generated by different sizes of wire grid on the minimum spark-ignition energy of a flowing propane-air mixture. Gas-stream velocity, size of turbulence promoter, and distance from the promoter plate to the electrodes on minimum ignition energy were evaluated and the effects are shown in figures.
Date: January 14, 1953
Creator: Swett, Clyde C., Jr. & Donlon, Richard H.
Partner: UNT Libraries Government Documents Department

Theoretical calculation of the power spectra of the rolling and yawing moments on a wing in random turbulence

Description: Report presenting calculations of the correlation functions and power spectra of the rolling and yawing moments on an airplane wing due to the three components of continuous random turbulence. Specific numerical calculations are made for a pair of correlation functions given by simple analytic expressions which fit available experimental data.
Date: December 1956
Creator: Eggleston, John M. & Diederich, Franklin W.
Partner: UNT Libraries Government Documents Department

Theoretical calculation of the power spectra of the rolling and yawing moments on a wing in random turbulence

Description: The correlation functions and power spectra of the rolling and yawing moments on an airplane wing due to the three components of continuous random turbulence are calculated. The rolling moments to the longitudinal (horizontal) and normal (vertical) components depend on the spanwise distributions of instantaneous gust intensity, which are taken into account by using the inherent properties of symmetry of isotropic turbulence. The results consist of expressions for correlation functions or spectra of the rolling moment in terms of the point correlation functions of the two components of turbulence.
Date: September 6, 1956
Creator: Eggleston, John M. & Diederich, Franklin W.
Partner: UNT Libraries Government Documents Department

A suggested method for measuring turbulence

Description: The desirability of a quantitative measure of turbulence is emphasized, and a possible method of attack on the problem is discussed. Data are presented to show that the hot-wire anemometer has possibilities as an instrument for measuring turbulence. An apparatus consisting essentially of two hot wire, one parallel to the air flow and one at right angles to it, is suggested.
Date: June 1931
Creator: Taylor, C. Fayette
Partner: UNT Libraries Government Documents Department

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. The investigations of fluctuations carried out so far refer almost exclusively to the so-called isotropic turbulence. It represents a damping phenomenon; it is the simplest type of turbulence where merely the longitudinal fluctuations need to be measured. However, it is precisely nonisotropic turbulence which involves the most essential problem of the turbulent exchange movement and the turbulent apparent friction. Investigation of nonisotropic turbulence requires measurement of longitudinal and transverse fluctuations.
Date: August 1951
Creator: Reichardt, H
Partner: UNT Libraries Government Documents Department

Measurement and analysis of turbulent flow containing periodic flow fluctuations

Description: Report presenting techniques for the measurement of the energy spectrum of flow fluctuations in both axial and lateral flow directions. Data indicated that the energy spectrum of the turbulence is not affected by periodic and random sound disturbances outside the frequency containing the disturbances.
Date: August 19, 1953
Creator: Mickelsen, William R. & Laurence, James C.
Partner: UNT Libraries Government Documents Department

Geometry Dependence of Stellarator Turbulence

Description: Using the nonlinear gyrokinetic code package GENE/GIST, we study the turbulent transport in a broad family of stellarator designs, to understand the geometry-dependence of the microturbulence. By using a set of flux tubes on a given flux surface, we construct a picture of the 2D structure of the microturbulence over that surface, and relate this to relevant geometric quantities, such as the curvature, local shear, and effective potential in the Schrodinger-like equation governing linear drift modes.
Date: August 10, 2009
Creator: H.E. Mynick, P. Xanthopoulos and A.H. Boozer
Partner: UNT Libraries Government Documents Department

An Enhanced Nonlinear Critical Gradient for Electron Turbulent Transport due to Reversed Magnetic Shear

Description: The first nonlinear gyrokinetic simulations of electron internal transport barriers (e-ITBs) in the National Spherical Torus Experiment show that reversed magnetic shear can suppress thermal transport by increasing the nonlinear critical gradient for electron-temperature-gradient-driven turbulence to three times its linear critical value. An interesting feature of this turbulence is non- linearly driven off-midplane radial streamers. This work reinforces the experimental observation that magnetic shear is likely an effective way of triggering and sustaining e-ITBs in magnetic fusion devices.
Date: May 11, 2011
Creator: J. L. Peterson, G.W. Hammett, D.R. Mikkelsen, H.Y. Yuh, J. Candy, W. Guttenfelder, S.M. Kaye, and B. LeBlanc
Partner: UNT Libraries Government Documents Department