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Development of Turbulence-Measuring Equipment

Description: "Hot wire turbulence-measuring equipment has been developed to meet the more stringent requirements involved in the measurement of fluctuations in flow parameters at supersonic velocities. The higher mean speed necessitates the resolution of higher frequency components than at low speed, and the relatively low turbulence level present at supersonic speed makes necessary an improved noise level for the equipment. The equipment covers the frequency range from 2 to about 70,000 cycles per second" (p. 1).
Date: 1954
Creator: Kovasznay, Leslie S. G.
Partner: UNT Libraries Government Documents Department

On the Spectrum of Isotropic Turbulence

Description: Note presenting measurements of the spectrum and correlation functions at large Reynolds number as well as a series of accurate spectrum measurements at lower Reynolds number. Results regarding decay, spectrum and correlation measurements in the GALCIT 10-foot tunnel, spectrum measurements in the 20-inch tunnel, moments of the spectrum, behavior of the spectrum at high frequencies, the spectrum at very large distances from the grid, and the spectrum of derivative are provided.
Date: November 1951
Creator: Liepmann, H. W.; Laufer, J. & Liepmann, Kate
Partner: UNT Libraries Government Documents Department

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

Convection of a pattern of vorticity through a shock wave

Description: An arbitrary weak spatial distribution of vorticity can be represented in terms of plane sinusoidal shear waves of all orientations and wave lengths (Fourier integral). The analysis treats the passage of a single representative weak shear wave through a plane shock and shows refraction and modification of the shear wave with simultaneous generation of an acoustically intense sound wave. Applications to turbulence and to noise in supersonic wind tunnels are indicated.
Date: September 26, 1952
Creator: Ribner, H. S.
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

Measurements of Lift Fluctuations Due to Turbulence

Description: Note presenting a study of the fluctuating lift of a rigid wing in turbulent flow and the power spectra of the lift and turbulent fluctuations. Using these measurements, the aerodynamic admittance of the wing was obtained. Results regarding the infinite wing and aspect-ratio effect are provided.
Date: March 1957
Creator: Lamson, P.
Partner: UNT Libraries Government Documents Department

The Theories of Turbulence

Description: "The theory of turbulence reached its full growth at the end of the 19th century as a result of the work by Boussinesq and Reynolds. It then underwent a long period of stagnation which ended under the impulse given to it by the development of wind tunnels caused by the needs of aviation. Numerous researchers, attempted to put Reynolds' elementary statistical theory into a more precise form. During the war, some isolated scientists - von Weizsacker and Heisenberg in Germany, Kolmogoroff in Russia, Onsager in the U.S.A. - started a program of research. By a system of assumptions which make it possible to approach the structure of turbulence in well-defined limiting conditions quantitatively, they obtained a certain number of laws on the correlations and the spectrum. Since the late reports have improved the mathematical language of turbulence, it was deemed advisable to start with a detailed account of the mathematical methods applicable to turbulence, inspired at first by the work of the French school, above all for the basic principles, then the work of the foreigners, above all for the theory of the spectrum" (p. 1).
Date: October 1955
Creator: Agostini, L. & Bass, J.
Partner: UNT Libraries Government Documents Department

Interaction of a Free Flame Front With a Turbulence Field

Description: "Small-perturbation spectral-analysis techniques are used to obtain the root-mean-square flame-generated turbulence velocities and the attenuating pressure fluctuations stemming from interaction of a constant-pressure flame front with a field of isotropic turbulence in the absence of turbulence decay processes. The anisotropic flame-generated turbulence velocities are found to be of about the same intensity as those of the incident isotropic turbulence, the lateral turbulence velocities being always lower, but the longitudinal velocity is somewhat increased for flame-temperature ratios over 7" (p. 599).
Date: January 25, 1955
Creator: Tucker, Maurice
Partner: UNT Libraries Government Documents Department

On the Statistical Theory of Turbulence

Description: A study is made of the spectrum of isotropic turbulence with the aid of the customary method of Fourier analysis. The spectrum of the turbulent motion is derived to the smallest wave lengths, that is, into the laminar region, and correlation functions and pressure fluctuations are calculated. A comparison with experimental results is included. Finally, an attempt is made to derive the numerical value of a constant characteristic of the energy dissipation in isotropic turbulence.
Date: January 1958
Creator: Heisenberg, W.
Partner: UNT Libraries Government Documents Department

A Relation of Wind Shear and Insolation to the Turbulence Encountered by an Airplane in Clear-Air Flight at Low Altitudes

Description: Memorandum presenting the observed gust experience of an airplane and information on the associated meteorological conditions to obtain a simple empirical relation for estimating the intensity of turbulence in the earth's friction layer. The relation does not discriminate between differences in turbulence intensity resulting from variations of flight altitude or diurnal variations of turbulence.
Date: September 13, 1951
Creator: Thompson, James K.
Partner: UNT Libraries Government Documents Department

Flight Investigation of the Effect of Atmospheric Turbulence on the Climb Performance of an Airplane

Description: Note presenting the results of an investigation consisting of a series of one-engine climb tests with a twin-engine transport airplane, which indicate that light turbulence of the type generally present in clear air over flat terrain has no significant effect on the average rate of climb for a series of runs. Turbulence does, however, increase the variation in the rate of climb from run to run. Results regarding mean rate of climb, standard deviation of the rate of climb, effects of climb duration, and implications of these results are provided.
Date: October 1951
Creator: Press, Harry & McClanahan, Herbert C., Jr.
Partner: UNT Libraries Government Documents Department

Combined Effect of Damping Screens and Streams Convergence on Turbulence

Description: Note presenting an analysis of the combined effect of a series of damping screens followed by an axisymmetric-stream convergence on the mean-square fluctuation-velocity intensities, scales, correlations, and one-dimensional spectra of a turbulence field convected by a main stream. Numerical results for the statistical quantities describing the turbulence field downstream of a screen-contraction configuration are obtained for the case of upstream isotropic turbulence.
Date: January 1953
Creator: Tucker, Maurice
Partner: UNT Libraries Government Documents Department

An Evaluation of Air-Borne Radar as a Means of Avoiding Atmospheric Turbulence

Description: "Gust-velocity measurements and air-borne-radar observations obtained during a transcontinental flight in July 1947 have been analyzed as part of a general investigation of the uses of air-borne radar. The analysis indicates that some reduction in turbulence and a consequent reduction in the risk of encountering the larger gust velocities may be obtained by avoiding portions of clouds giving a radar echo" (p. 1).
Date: November 22, 1948
Creator: Steiner, Roy
Partner: UNT Libraries Government Documents Department

Turbulence and Heat Stratification

Description: With applications to meteorology in view, the method of small oscillations is used to investigate the stability of a plane laminar boundary layer in which the density depends in a special way on the distance from the plate. It is found that for a constant Froude number the flow becomes more stable as the Richardson number increases until, at a critical value of the Richardson number that depends on the Froude number, the flow is stable for all disturbance wave lengths and Reynolds numbers. The calculated results are verified by experiment.
Date: October 1950
Creator: Schlichting, Hermann
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

Diffusion of heat from a line source in isotropic turbulence

Description: "An experimental and analytical study has been made of some features of the turbulent heat diffusion behind a line heated wire stretched perpendicular to a flowing isotropic turbulence. The mean temperature distributions have been measured with systematic variations in wind speed, size of turbulence-producing grid, and downstream location of heat source. The nature of the temperature fluctuation field has been studied" (p. 1).
Date: June 5, 1951
Creator: Uberoi, Mahinder S. & Corrsin, Stanley
Partner: UNT Libraries Government Documents Department

Correlations involving pressure fluctuations in homogeneous turbulence

Description: Report presenting an investigation of the correlations of pressure with itself and of pressure with two velocity components for the case of isotropic turbulence. The correlations are expressed in terms of correlations involving two velocity components at a point and two velocity components at another point.
Date: January 1954
Creator: Uberoi, Mahinder S.
Partner: UNT Libraries Government Documents Department

Intensity, scale, and spectra of turbulence in mixing region of free subsonic jet

Description: Report presents the results of the measurements of intensity of turbulence, the longitudinal and lateral correlation coefficients, and the spectra of turbulence in a 3.5-inch-diameter free jet measured with hot-wire anemometers at exit Mach numbers from 0.2 to 0.7 and Reynolds numbers from 192,000 to 725,000.
Date: April 24, 1956
Creator: Laurence, James C.
Partner: UNT Libraries Government Documents Department

The effect of turbulence on the drag of flat plates

Description: "In determining the effect of turbulence on the forces exerted on bodies in the air stream of a wind tunnel, it is commonly assumed that the indications of the standard Pitot-static tube used to determine the air speed are not dependent on the turbulence. To investigate the truth of this assumption, the drag of a normally exposed flat plate, the difference in pressure between the front and rear of a thin circular disk, the rate of rotation of a vane anemometer, and the pressure developed by a standard Pitot-static tube were measured in an air stream for several conditions of turbulence. The results may be interpreted as indicating that there is no appreciable effect of turbulence on the vane anemometer and the standard pitot-static tube, but that there is small effect on the drag of a flat plate and the pressure difference between front and rear of a disk" (p. 129).
Date: June 22, 1935
Creator: Schubauer, G. B. & Dryden, H. L.
Partner: UNT Libraries Government Documents Department

Effect of turbulence in wind-tunnel measurements

Description: This paper gives some quantitative measurements of wind tunnel turbulence and its effect on the air resistance of spheres and airship models, measurements made possible by the hot wire anemometer and associated apparatus in its original form was described in Technical Report no. 320 and some modifications are presented in an appendix to the present paper. One important result of the investigation is a curve by means of which measurements of the air resistance of spheres can be interpreted to give the turbulence quantitatively. Another is the definite proof that the discrepancies in the results on the N. P. L. Standard airship models are due mainly to differences in the turbulences of the wind tunnels in which the tests were made.
Date: August 20, 1929
Creator: Dryden, H. L. & Kuethe, A. M.
Partner: UNT Libraries Government Documents Department

Preliminary experimental investigation of low-speed turbulent boundary layers in adverse pressure gradients

Description: Report presenting measurements of velocity profiles and skin friction in subsonic turbulent boundary layers with adverse pressure gradients. The skin friction in an adverse pressure gradient was found to decrease steadily with distance to a value approaching zero for the region of separation. Results regarding the mean velocity distribution and separation, comparison of experimental values with semiempirical relations, and wall shearing stress are provided.
Date: October 1953
Creator: Sandborn, Virgil A.
Partner: UNT Libraries Government Documents Department

Summary of locations, extents, and intensities of turbulent areas encountered during flight investigations of the jet stream from January 7, 1957 to April 28, 1957

Description: "A summary of the locations, extents, and intensities of turbulent areas encountered during a flight investigation of the jet stream is presented. The data were obtained from NACA VGH time-history records" (p. 1).
Date: March 3, 1958
Creator: Copp, Martin R.
Partner: UNT Libraries Government Documents Department