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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 107 for “"drag coefficient"”.
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Drag coefficient and damping of moorings and their effect on FPSO's response
… thesis are to investigate mooring line damping, drag coefficient of mooring chain and their effect on the motions of FPSOs. In particular the aim is to determine the CD values of a stud-less chain under different flows by numerical methods due to limited CD data for chains. A turret moored FPSO …
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The tangential drag of an axially oscillating cylinder
An experimental investigation of the tangentiaì drag of an axially oscillating cylinder is presented. Deep-sea mooring cables are oscillated sinusoidally at ocean wave amplitudes and frequencies, and experimenta1 values of the tangential (friction) drag coefficient are obtained. The experimental …
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Hydrodynamic drag force in liquids
… falling at constant velocity, the hydrodynamic drag force, D, is equal to the weight of the sphere, and the drag coefficient, CD, in the formula for the drag force, D = CD( 12rv2 )A could be evaluated as a function of Reynolds number, NR = rvah , and ball radius, a. In these formulas D is the …
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A Feasibility Study of Dynamical Assimilation of Tide Gauge Data in the Chesapeake Bay
… gauges is investigated to estimate the bottom drag coefficient and surface stress as a first step in improving modeled tidal and wind-driven circulation in the Chesapeake Bay. A two-dimensional shallow water model and an adjoint variational method with a limited memory quasi-Newton optimization …
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Optimization parameters for a membrane polygonal body of revolution with zero meridional stress and its application to parachutes
… by regular polygons is optimized for maximum drag and drag coefficient. The meridional, or primary members, carryall of the radial loads and the membrane structure transfers applied pressure loads to the primary members. The shape of the secondary membrane is found such that the performance …
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Droplet Drag Modeling on Spray Conditions
… on droplet dynamics. Although droplet drag is a classical area of study, there are still theoretical gaps in understanding the motion of large droplets. In applications such as spray combustion, droplets of various sizes are generated and move with the flow. Large droplets tend to …
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Investigating if MLB pitchers are self-selecting for high or low drag balls
The drag coefficient of 4928 batted balls in the MLB in 2019 were measured and matched with 121 pitchers who threw the ball to examine if they are statistically more or less likely to select a high or low drag ball to throw. It was hypothesized that (1) pitchers are routinely selecting for either …
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Scale effects in testing of a monopile support structure submerged in tidal currents.
… observations were made: 1) For the DSE, the drag coefficient of scale models within the subcritical flow regime varies as a function of a non-dimensional length and velocity scale. Equations for estimating the scale effects are presented. 2) The TSE investigation demonstrates a novel …
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The drag and lift characteristics of a cylinder placed near a plane surface
Surface pressure, drag and lift coefficients have been experimentally determined for a right circular cylinder located near a plane surface and placed in a cross flow of air. Parametric studies were carried out for Reynolds numbers varying from 90,000 to 250,000, three plate lengths and a variety …
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An experimental investigation of the variation with water depth of lift or drag coefficients of a body on or near the bottom of a flowing stream
… the influence of the depth of water upon the coefficients of lift and drag of a submerged body on or near the bottom of a flowing stream. This investigation made use of the facilities of the Rice University wave tank. Two types of models were employed in this study, an upright flat plate …
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Experimental Determination of an AUV's Drag Resistance in a Towing Tank
… for the dynamics of the system, including the drag resistance of the AUV. This paper examines the method of using a calm-water resistance test in a towing tank to determine the resistance of an AUV. A scale model of a survey class AUV was created using a 3d printer and mounted in a towing tank. …
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Hydrodynamic Drag and Flow Visualization of IsoTruss Lattice Structures
Hydrodynamic drag testing was conducted for eleven different configurations of IsoTruss® lattice structures. Flow visualization of prototypical IsoTruss® wind towers was also performed using Particle Image Velocimetry instrumentation. The drag test and flow visualization specimens included 6-node …
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Hydrodynamic performance of multi-component structures in oscillatory flow, from blow-out preventer to dual Cylinder interference
… show that the experimental measured hydrodynamic coefficients are drastically different from the industrial recommended modeling coefficients that the added mass coefficient Cm and the drag coefficient Cd both have a much larger value than the industrial model provided, and they vary significantly …
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Aerodynamic drag on deformable and active structures in high Reynolds number conditions
… a novel mechanism to control the aerodynamic drag on cylinders, in the critical Reynolds number regime. We created both axially grooved and dimpled specimens, comprised of latex membranes stretched over rigid acrylic skeletons. By decreasing the internal pressure of the specimens, the latex …
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Fluid dynamics of sinking carbon dioxide hydrate particle releases for direct ocean carbon sequestration
… the impact on marine life. We developed a drag coefficient model for cylindrical particles in free fall. Applying the new drag coefficient model to recently observed field injections to predict their descent, the recently produced field particles were estimated to have had a ~ 16% reaction …
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Development of a Methodology to Measure Aerodynamic Forces on Pin Fins in Channel Flow
… to simultaneously measure aerodynamic lift and drag forces on a pin fin. After eliminating the detrimental environmental influences, forces as small as one-tenth the weight of a paper clip are successfully measured. Although the drag of an infinitely long cylinder in uniform cross flow is well …
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Liquid flow past nanoscale objects
… past a CNT in a small domain and show that the drag coefficients can be modeled as Stokes flow past an array of CNT's with an effective diameter. The effective diameter can be obtained from the radial density profile around the CNT. We also apply a uniform flow of liquid argon and SPC/E water …
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Flow and solute transport in random cylinder arrays : a model for emergent aquatic plant canopies
… presents laboratory measurements of the mean drag, turbulence structure and intensity, and lateral dispersion of passive solute in arrays of randomly-distributed cylinders, a model for emergent, rigid aquatic plants. Mean drag per cylinder length normalized by the mean interstitial fluid …
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The effects of freestream turbulence on the drag of a sphere
… 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 of different sizes in addition to altering the freestream …
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Wind stress over the open ocean
… The results were used to correct the measured drag coefficient, CD10N , and wind speed estimates. The resulting mean wind stress to wind speed relationship: 1000 CD10N = 0.53 + 0.064U10N 6 !U10N ! 26 m/ s confirmed those obtained by Smith (1980) and Large and Pond (1981). Wave measurement …
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