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Showing 1 to 13 of 13 for “"Blockage Ratio"”.
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Investigation of Pulse Detonation Engines: the Effect of Variable Blockage Ratio on the Deflagration to Detonation Transition
… approaches of achieving detonation through deflagration-to-detonation transition most of which use evenly spaced obstacles with a specified constant blockage ratio to generate turbulence and pressure fluctuations. There have been few efforts to study effects of varying blockage ratio as a function …
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Extended Momentum Model for Single and Multiple Hydrokinetic Turbines in Subcritical Flows
… in open channel flows. The new model includes blockage ratio and Froude number as independent variables, which are inferred in advance to yield a single solution in the prescribed domain. The theoretical extension is integrated with the Blade Element Theory in a Double Multiple Streamtube model …
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The Effect of Axial Spacing of Constant and Variable Blockages on the Deflagration-to-Detonation Transition in a Pulse Detonation Engine
… the effects of obstacle spacing on the deflagration-to-detonation transition section length in a pulse detonation engine. Testing was conducted with one hundred and ninety-five different obstacle, and spacing configurations. The configurations included constant, as well as variable spacing …
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Flow and Heat Transfer in Tubes with Obstacles
… ends and annular obstacles, each having a flow blockage of either 0.15 or 0.3. The axial distribution of heat transfer coefficient was measured downstream from the downstream end of the obstruction over a distance of 3 to 70 tube diameters. The experimental data indicate that heat transfer …
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The Role of Swirl in the Flow Structure and Response of Premixed Flames
… those goals a range of bluff body based configurations with swirl numbers ranging from 0.30 to 0.97 are considered. Initially the recirculation zone and flow structure are compared under isothermal and reacting conditions. The recirculation zone created through vortex breakdown mechanisms is …
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Aerodynamic drag reduction of a racing motorcycle through vortex generation
… layer, delaying boundary layer growth and separation. In testing performed in the West Virginia University Closed Loop Wind Tunnel a maximum reduction of 118 drag counts (10.1%) was measured. Due to an abnormally high blockage ratio tests were conducted Old Dominion University's Langley Full …
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Scaling Effects on the Hydrodynamics and Performance of Current Turbines
… objective is to characterize the effects of the blockage ratio, Reynolds number, and Froude number on turbine performance and flow dynamics with the goals of better understanding the relative influence of these parameters and improving the quality of laboratory-scale testing. The second objective …
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Numerical Investigation of Mixing Tabs in Multi-Ring Entraining Diffuser in Air-Air Ejectors
… reduced overall ejector pumping performance. Tab blockage ratio was also varied at 1%, 2% and 4% blockage per tab. Increasing blockage ratios was associated with increasing diffuser pumping, but worsened pumping at standoff, however, total pumping was unchanged. A location study identified that …
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ΕΞΟΜΟΙΩΣΗ ΡΟΙΚΟΥ ΠΕΔΙΟΥ ΑΞΟΝΟΣΥΜΜΕΤΡΙΚΩΝ ΣΩΜΑΤΩΝ ΣΕ ΘΑΛΑΜΟ ΜΕΤΡΗΣΕΩΝ ΑΕΡΟΣΗΡΑΓΓΑΣ
… VISCOUS EFFECT CAUSES AN INCREASE OF THE TUNNEL BLOCKAGE RATIO AND IT IS INTRODUCED INTO THE CALCULATION SCHEME BY MEANS OF AN ADDITIONAL PRESSURE GRADIENT. THE BOUNDARY LAYER DEVELOPMENT ON THE MODEL SURFACE AND THE TUNNEL WALLS IS CALCULATED APPLYING ROTTA'S INTEGRAL METHOD AND WHEN …
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Strongly-Coupled Conjugate Heat Transfer Investigation of Internal Cooling of Turbine Blades using the Immersed Boundary Method
… simulations, a ribbed duct geometry with a blockage ratio of 0.3 is simulated at a bulk Reynolds number of 10,000 with a conjugate boundary condition applied to the rib surface. The nominal Biot number is kept at 1, which is similar to the comparative experiment. As a means to overcome a …
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Multiphase Flow Dynamics in Confined Domains—A DNS Study of Bubbly, Thermal and Riblet-Induced Turbulence
… systematically studying three canonical configurations—liquid–liquid emulsions in Rayleigh–Bénard convection, buoyancy-driven bubbly flows in vertical channels, and channel flows over riblet-structured walls—this work advances the physical understanding of multi-physics interactions across a …
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The Wall Pressure Spectrum of High Reynolds Number Rough-Wall Turbulent Boundary Layers
… of a turbulent boundary layer and the generation of a fluctuating pressure field imposed on the surface. While numerous studies have investigated the wall pressure fluctuations over zero-pressure gradient smooth walls, few studies have examined the effects of surface roughness on the wall …
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Development of an experimental methodology for appraising the dynamic response of tethered tidal turbines
… such as the selection of test facilities, blockage ratio limits or safety factors in applied loads were discussed. Instruments to measure the dynamic motion of turbines were specified, along with other instruments to measure power, thrust, angular velocity and flow speed. The final steps in …