Global ETD Search
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Showing 1 to 15 of 15 for “"velocity fluctuation"”.
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Interaction of a vortex pair and a free-surface : numerical simulation
… intensity, the kinetic energy dissipation and velocity fluctuations. The turbulence intensity reaches a maximum at the level of the center of the primary vortex, and then decreases significantly as the free-surface is approached. This decay is due to a very large increase of the turbulent …
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Microscopic description of the granular fluidity field in nonlocal flow modeling
… is found to be a kinematic variable given by the velocity fluctuation and packing fraction. This is verified with many discrete element simulations, which show the operational fluidity definition, solutions of the fluidity model, and the proposed microscopic formula all agree. Kinetic theoretical …
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Numerical Simulation of Turbulent Particle Diffusion
… a modified Markov chain based on a normalized velocity fluctuation was found to be important to avoid unphysical wall-ward particle fluxes. Also, the incremental drift velocity for the Markov chain (required for inhomogeneous turbulent flows) was extended to include effects of particle inertia …
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Quantification of linear and nonlinear energy transfer processes in a plane wake
… wakes is characterized by the development of the velocity-fluctuation field from a spectrum of weak random background noise in the initial laminar wake to a nearly featureless broad spectrum of intense fluctuations within the turbulent wake. This transition has also been described as a sequence of …
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Numerical Investigation of turbulent coupling boundary layer of air-water interaction flow
… flowing fluids are coupled through continuity of velocity and shear stress condition across the interface. Pseudo-spectral method is used in each flow subdomain with Fourier expansion in streamwise and spanwise directions and finite difference in vertical direction. Statistically quasi-steady flow …
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Some Features of Tip Gap Flow Fields of a Linear Compressor Cascade
… are used in the studies: a three-orthogonal-velocity-component fiber-optic laser Doppler anemometer (3D-LDA) system, surface oil flow visualization, and a scanivalve system for static pressure measurement through pressure ports on the end-wall. From the details of the oil flow visualization …
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Turbulence measurements of heated supersonic slot injection into a supersonic stream
… effects on the flow of these changes in density, velocity and temperature was investigated. Measured quantities included the mean and rms levels of the mass flux and total temperature. Nanosecond Shadowgraphs and spark Schlieren photographs were taken. The Favre-averaged velocity fluctuation, …
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Effect of Adaptive Tabs on Drag of a Square-Base Bluff Body
… total drag force measurements and hotwire velocity fluctuation measurements. These tests were repeated with tabs on the model’s trailing edge at the three different tab heights and without tabs at all three test speeds.</p> <p>The base pressure measurements showed a decrease in average base …
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Modelling and diagnostic study of flow in an optical engine with negative valve overlapping for homogeneous charge compression ignition
… with periodic engine operation induce gas fluctuations over time and cylinder volume. This affects the thermal inhomogeneity of the in-cylinder gas mixture composition. A novel approach to the formation of in-cylinder flow that promote Homogeneous Charge Compression Ignition HCCI engine by …
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Laser Doppler velocimetry measurements of particle velocity fluctuations in a concentrated suspension
… average kinetic energy contained in the particle velocity fluctuations. These models have not yet been compared systematically with experimental data. In addition, the "temperature" models assume isotropic particle velocity fluctuations, since the "suspension temperature" is given as a scalar, in …
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Turbulent flowfield downstream of a perpendicular airfoil--vortex interaction
… noise, particularly BWI noise. Three-component velocity and turbulence measurements were made in unprecedented detail using a computerized miniature four-sensor hot-wire probe system; revealing much about the structure and behavior of this flow over a range of conditions. The interaction between …
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The dynamics of the outer region of wall-bounded turbulence : La dinámica de la zona exterior en la turbulencia de pared
… conditions are substituted by prescribed velocity disturbances that destroy the near-wall energy cycle characteristic smooth-walled flows. In this sense, the present DNSes can be understood as a simulation of a turbulent flow consisting on a core region without a near-wall region. The …
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High Reynolds Number Turbulent Boundary Layer Flow over Small Forward Facing Steps
… wall pressure, single and 2 point wall pressure fluctuations, single and 2 point velocity fluctuations and, oil flow visualization. Pressure fluctuation measurements were made 5 boundary layer thicknesses upstream of step to 22 boundary layer thickness (or 600 step heights for smallest step size) …
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Covert-inspired flow control devices for lift enhancement and stall mitigation
… compared to the baseline, which increases the velocity over the suction side of the airfoil. The distinctions between the flap-induced lift enhancements on the soft and sharp stall airfoils suggest that the flap can be used as a tunable flow control device for the sharp stall airfoil, while for …
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Stochastic modelling of contaminant transport in porous media
… medium as stochastic variation of the fluid velocity, produced by pore wall impacts. This gives a stochastic differential equation for fluid displacements, and solute transport is obtained as the cumulative effect over all realisations of the stochastic path. It is shown that applying …