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Showing 1 to 20 of 32 for “"Velocity ratio"”.
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Characterization of mixing in a coaxial jet mixer for nanoparticle fabrication
… of mixing. The average Reynolds number and velocity ratio were varied. The velocity ratio varied between 0.1 and 10. The Reynolds number varied between 200 and 1800. Mixing times on the order of 1 to 50 ms were measured in the device. The mixing time was found to be proportional to average …
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Investigation on the Interaction of an Impinging Jet with Cylinder Wakes
… of cylinder-jet distance, cylinder diameter, and velocity ratio on jet oscillation and heat transfer rate. The range of cylinder-jet distance and velocity ratio tested are S/d = 2 – 4 and VR = 4 – 12, respectively. The flow interaction mechanism leading the jet oscillation is analyzed using TKE, …
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Experiments and simulation of shaped film cooling holes fed by crossflow with rib turbulators
… were installed in two geometric configurations inside the internal crossflow channel, at 45° and 135°, to assess the impact on film cooling effectiveness. Film cooling hole inlets positioned in both pre-rib and post-rib locations tested the effect of hole inlet position relative to the …
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Turbulent Simulations of a Buoyant Jet-in-Crossflow
… at least for a high Reynolds number JICF. The velocity ratio of the jet being the ratio of the jet velocity to the free--stream flow velocity. Deviating from a velocity ratio of one has provided information on the variability of the forcing on the plate the jet exits from, as well as in the …
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Actuator Disk Theory for Compressible Flow
… incompressible value of 0.593 and occurs at a velocity ratio between the far downstream and the free-stream that is lower than the incompressible value of 0.333. From incompressible to a free-stream Mach number of 0.8, the Betz limit increases by 0.021 while its corresponding velocity ratio …
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Laser Doppler anemometry measurements of a confined turbulent water jet with a uniform background flow
… flow reversal outside the jet, but if the coflow velocity is not small compared to the jet velocity, the jet will no longer be self-preserving. Thus, the objective is reached in the limit as the coflow approaches zero, but in the absence of reverse flow. In the present study, a jet with several …
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Jets in a crossflow including the effects of dual arrangements, angle, shape, swirl and high turbulence
… as surface pressure distributions and mean velocity vector plots and turbulence intensities and Reynolds stresses in the jet plume. Rectangular jets (length/width=4) and circular jets were tested. The rectangular jets were aligned streamwise as single and side-by-side dual jets. For the …
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A computational fluid dynamics model for sediment movement based on the unit stream power approach
… Number (Lui 1957), which represents the shear velocity-settling velocity ratio, is related to the unit stream power and is applied as an alternative incipient motion criterion. The Movability Number, as adapted by Armitage (2001) to account for topography, is utilised for scour hole predictions.
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Bench blast modeling: Consequences of crushed zone, wave front shape, and radial cracks.
… crushed zone diameter and some dimensionless ratios of explosive and rock properties. The ratios are velocity ratio, characteristic impedance ratio, medium stress ratio, and detonation pressure ratio. The empirical relations for granite, salt, and limestone in combination with a variety of …
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Flow characteristics of a transverse water jet into an unconfined water channel
… and numerically. For this detailed study, three velocity ratios 2, 3 and 4 and two water depths 100 and 200 mm were considered. The objectives of this study were: To explore the velocity distribution for different velocity ratios To analyse the turbulence characteristics of the water jet in a …
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Combining body wave tomography, surface wave inversion, seismic interferometry and laboratory measurements to characterize the black shales on Bornholm at different scales
… interferometry to obtain the P-wave and S-wave velocity models of the subsurface. The P-wave velocity models which were determined for all three profiles clearly locate the Alum Shale layer between the Komstad Limestone layer on top and the Læså Sandstone Formation at the base of the models. The …
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Instabilities of a compressible mixing layer
… or is specified by the hyperbolic tangent velocity profile. The effects of viscosity, Mach number, the velocity and temperature ratios on the growth rate are determined. Unlike the boundary layer flow, viscosity has a stabilizing effect on the mixing layer flow. Increasing the temperature …
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Using wave attenuation techniques for monitoring of stress levels
… means of stress measurement. Wave propagation velocity has long been applied to the investigation of the upper mantle and crust stress. Recently, it has also been applied to rock burst prediction and mine site investigations. Another parameter for investigating stress in rocks is the …
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Planar Laser Induced Fluorescence Experiments and Modeling Study of Jets in Crossflow at Various Injection Angles
… the jet-in-crossflow was tested with various velocity ratios and jet injection angles. Results indicated the degree of wall separation for different injection angles and demonstrate both the time-averaged trajectories as well as select near-wall concentration results for varying jet momentum …
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Planar Velocity Measurements in an Incompressible and a Weakly Compressible Mixing Layer
For the weakly compressible mixing layer, the velocity ratio was 0.53, the density ratio was 0.67, and the convective Mach number was 0.38. At the location where the PIV images were obtained, Rex = 3.7 x 106 , Redw = 1.8 x 105, and Rx/lambda = 18. The planar velocity fields obtained in this study …
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The turbulent structure of the jet in cross-flow
… Vortex Pair (CVP) plane for a high velocity ratio and jet Reynolds number. Statistical measurements at various downstream locations and velocity ratios are presented. Probability density functions of the streamwise vorticity field showed that each CVP core is instantaneously made of …
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Experimental and analytical investigation of multiple jets in a cross-flow
… jet, tandem jets, and side-by-side jets for a velocity ratio of 2, and a jet spacing of 4 for the latter two cases. The measurements yielded axial mean velocity, turbulence intensities, and Reynolds stresses for four downstream stations for the single jet and two downstream stations for the …
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Stochastic prediction of collapse of building structures under seismic excitations
… of structural collapse with systematic incorporation of uncertainty still remains a question, especially for structural evaluation and design of actual structures. The most commonly used approach to assess the collapse capacity of structures under extreme earthquakes is based on the concept of …
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The development of passive flow control vortices
… of a 350mm by 250mm wind tunnel and had a separation zone on its trailing edge.<br/>Surface flow visualisation was used to select VVG spacings and SJVG velocity ratios for effective separation control and investigate surface flow. Instantaneous and mean parameters downstream of the VVG and SJVG …
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Some unsteady features of turbulent boundary layers
… diverging test section with amplitude to mean velocity ratio of 0.8. In steady flow cases, both zero and favorable pressure gradient flows show good two-dimensional flow characteristics and mean flow characteristics are compared with other researchers’ data. Measured power spectral data show …
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