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Showing 1 to 20 of 129 for “"turbulence intensity"”.
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Characterizing the Influence of Turbulence Intensity on Energy Production at the Vineyard Wind 1 Farm
Turbulence in the atmospheric boundary layer mitigates wake losses between turbines and is critical to power generation by wind farms. As offshore wind energy development increases in the United States, it is necessary to understand the impact turbulence intensity uncertainty has on predicting the …
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Influence of initial turbulence intensity on the heat and moisture transfer through a recirculated air curtain
… which accounts for the influence of the initial turbulence intensity on the transfer of heat and moisture across a recirculated air curtain. The control of the turbulence intensity at the nozzle exit of an air curtain permits control of heat and moisture transfer and therefore the energy required …
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Wind plant annual energy production maximisation and efficiency improvement with considerations for thrust and turbulence intensity
… wake interactions between turbines that increase turbulence intensities and consequently loads within the WP hence hampering its power and energy efficiency. Although sparse turbine deployments are common offshore to reduce wake effects and maximise efficiency, these resulting large T-2-T …
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Numerical investigation of the influence of elevated turbulence levels on the cooling effectiveness of an anti-vortex hole geometry
… a commercial CFD code (STAR-CCM+) with varying turbulence intensity and length scale using the k-o SST turbulence model. Both steady and unsteady results were considered in order to investigate the effects of freestream turbulence intensity and length scale on this novel anti-vortex hole (AVH) …
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Boundary-layer analysis and measurement of Newtonian and non-Newtonian fluids
… on a bluff body in drag-reducing flows is the turbulence intensity rather than the Reynolds number. For turbulence intensity less than 0.7% polymer addition induced delayed separation. For turbulence intensity over 1% the opposite effect was true. Time-averaged velocity profiles of water did …
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The effects of freestream turbulence on the drag of a sphere
The effects of freestream turbulence intensity and integral length scale as freestream turbulent parameters on the drag coefficient of a solid sphere were experimentally investigated in a closed-circuit wind tunnel. The Reynolds number, Re = Ud/ν, was varied from 2.2×104 to 8×10 4 by using spheres …
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Investigation of Noise Sources in Three-Stream Jets using Turbulence Characteristics
… comparison of eddy convection velocity and turbulence measurements in three-stream nozzles. A Time-Resolved Doppler Global Velocimetry (TR-DGV) Instrument was applied to the Nozzle Acoustic Test Rig (NATR) at NASA's Aero-Acoustic Propulsion Lab (AAPL) to measure convection velocity. Particle …
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The Effects of Curvature on Turbulent Boundary Layers Over a 3D Bump Geometry: An Experimental Study Using BeVERLI Hill
… among curvature, pressure gradients, and turbulence characteristics. The study examines the mean velocity, Reynolds shear stresses, pressure gradient, turbulence intensity, and pressure coefficient variations in relation to the bump curvature. The results are consistent with prior studies …
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The Design, Fabrication, and Evaluation of a Low-Speed, Low-Turbulence, Anechoic Wind Tunnel
… in propellers and fans, a low-speed, low-turbulence, anechoic wind tunnel was designed, fabricated and evaluated at Embry-Riddle Aeronautical University.</p> <p>This open circuit wind tunnel was designed using several other existing wind tunnels as a guide and incorporated an open jet test …
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The effect of turbulence on survival, dispersal, and swimming behavior of grass carp eggs and larvae
… are more susceptible to damage via enhanced flow turbulence levels and altered flow conditions. In order for these alternative strategies to be effective, is necessary to study the physics underlying the movement of eggs and larvae in streamflow, and to quantify the turbulence thresholds that …
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Interaction of a vortex pair and a free-surface : numerical simulation
… and kinetic energy, and the generation of turbulence in the flow. In particular, the turbulence characteristics have been explored at Reynolds number Re =1000. In this flow, we identified a thin free-surface layer characterized by very fast variations of the turbulence intensity, the …
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A fractal analysis of premixed turbulent flames
… flames was investigated over a range of turbulence conditions. For this purpose a turbulent combustion rig was designed and built in which the turbulence intensity and scale could be independently varied by means of a set of grids. The relative turbulence intensity varied from 0.5 to 8.6 …
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The diode array velocimeter
… as well as one component of time-averaged turbulence intensity. The concept for the DAV is rather simple. It also has an advantage over existing laser velocimeters in that it is relatively inexpensive. Measurements made with the prototype DAV are compared to those made by a single hot-wire …
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Flow through Rigid Vegetation Hydrodynamics
… within the canopy to develop velocity and turbulence intensity profiles and observe the changes in the flow characteristics as water travels through a vegetation array simulated by rigid dowels. Velocity data were collected with a one dimensional laser Doppler velocimeter (LDV) under single …
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Isosurface Interactions Within Turbulent Premixed Hydrogen and Hydrocarbon Flames
… of each type of topology changes with changes in turbulence intensity. With increasing turbulence intensity in hydrocarbon flames, the fraction of product pockets and tunnel formation events increases whereas the fraction of reactant pockets and tunnel closure events decreases. The results for …
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Flowfield measurements in the vortex wake of a missile at high angle of attack in turbulence
… for flowfield variables with elevated levels of turbulence; to determine the location and intensity of the asymmetric vortices in the wake of the VLSAM model at a raised level of freestream turbulence; and to display the asymmetric vortices by velocity mapping and pressure contours. The purpose …
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Chaos Control of an Open Shear Flow: A Novel Control Strategy and its Experimental Demonstration in an Axisymmetric Jet
… to control the coherent structure dynamics and turbulence in the near field of an axisymmetric jet is presented. Experiments were performed in an initially laminar circular jet, housed in a low-noise anechoic chamber. Periodic flow states involving various sequences of vortex ring formation and …
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Velocity, temperature and turbulence measurements in air under combined free and forced convection conditions
… of 5000 to 14000. Preliminary velocity and axial turbulence intensity measurements in isothermal flows for Reynolds numbers of 5000 to 32000 are also reported. Velocity and temperature distributions were measured over a range of heat fluxes at Reynolds numbers of approximately 5000 and 8000 and at …
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Steady and unsteady cascade measurements
Velocity and turbulence intensity measurements were made in a linear stationary cascade of compressor blades under high angles of attack. Laser-doppler velocimetry and flow visualization were used. A method was developed for inducing propagating stall and some triggered ensemble averaged velocity …
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Wall-Jet Turbulence and Mixing Control by Way of a Pulsed Inlet Velocity
<p>Understanding wall-jet-induced turbulence and mixing is an important challenge in modern engineering, as drag reduction and mixing enhancement are attainable by modifying the flow development. Simulations are performed to investigate the effect on skin friction and flow mixing due to introducing …
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