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Showing 1 to 20 of 143 for “"Wall Shear"”.
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Wall shear measurements in arterial flows
… turbulent behavior, thereby maintaining normal shear levels. The presence of vortical flow structures, however, alters the hemodynamical characteristics within the system, which has significant effect upon shear stress (SS) and wall shear stress (WSS) levels, as well as particle residence times. …
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Development of a new wall shear stress gauge for fluid flows
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1988.
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Studies of the Wall Shear Stress in a Turbulent Pulsating Pipe Flow
… are presented of the time variation of the wall shear stress caused by the imposition of a sinusoidal oscillation on a turbulent pipe flow. The amplitude of the oscillation is small enough that a linear response is obtained and the dimensionless frequency, (omega)('+), is large compared to …
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Particle-wall shear stress measurements within the standpipe of a circulating fluidized bed
… which could be due to forces such as particle-wall shear stress.;In this research the one-dimensional gas-solids mixture momentum balance is applied to the standpipe. Neglecting acceleration effects, the important forces are the gas and solids phase pressure drop, weight of the bed, and the …
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Wall Shear Stress Distribution for Flow Around a Circular Cylinder-- Reynolds Number Range 60-340
Made available in DSpace on 2014-12-08T23:18:21Z (GMT). No. of bitstreams: 1 6812106.pdf: 2889700 bytes, checksum: 06c5b94427c36ae993139a650c4fa7a3 (MD5) Previous issue date: 1968
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Amplitude modulation of velocity and wall shear stress in turbulent channel flow with hemispherical roughness
"Near-wall turbulence cycles tend to be self-sustained in low Reynolds number wall-bounded turbulent flows. However, large-scale structures that reside in the outer region of the flow grow more energetic as Reynolds number increases and impart strong ""footprints"" on the near-wall turbulence. In …
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A Computational Fluid Dynamics based model that predicts wall shear stress in CANDU outlet feeder pipes
Wall thinning of carbon steel in CANDU reactor outlet feeder pipes due to Flow Accelerated Corrosion (FAC) is identified as one of the challenges for CANDU reactors since it would force them to shut down due to safety reasons. Several models have been developed over time to predict the corrosion …
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Implementation of drop-based oil flow interferometry to estimate wall shear stress in three-dimensional flows
… approach using silicone oil droplets to measure wall shear stress in three-dimensional flows. Wall shear stress is a critical parameter in fluid dynamics, significantly affecting aerodynamic drag and turbulent flow behavior. Accurate measurement for wall shear stress is essential for validating …
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Experimental Study of Wall Shear Stress Modification by Surface Coating: Pressure Drop Measurements in a Rectangular Channel
… drag reduction in rectangular channel flow over walls with specific hydrophobic or hydrophilic properties was obtained with pressure drop measurements along the channel for a range of Reynolds numbers between 350 and 5900. Several commercially available materials and coatings were chosen in order …
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A study of velocity profile models and wall shear stress for two and three-dimensional turbulent boundary layer flows
… direction. The various methods of determining a wall shearing stress by semi-empirical considerations for two and three-dimensional flows was discussed. A direct measurement of the wall shearing stress in a three-dimensional flow field was used to infer the most accurate method of applying …
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Part I--Mean and fluctuating wall shear stress measurements ; Part II--Fluid-loaded elastic slab undergoing line and point load excitations
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1993.
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Prototype Development and Feasibility Assessment of a Vertically Mounted Floating Element Skin Friction Balance
Wall shear stress is one of the most essential scaling parameters used in fluid dynamics. It is significant because it helps us compare results in different experimental studies. The accurate measurements of wall shear stress will be instrumental in improving the existing empirical models and …
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A Computational Model of Aneurysmal Flow at the Abdominal Aorta
… that occurs in response to degradation of the wall structure. The present research focused on developing a realistic hemodynamic model of the aneurysm using a new method to assign boundary conditions. A three element Windkessel model was coupled to the 3D geometry model of the disease in order …
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Near-wall similarity in two- and three-dimensional turbulent boundary layers
Static pressure, mean velocity, indirect wall shear from Preston tubes, direct wall shear using a two-dimensional (single line of action) floating element device, and direct wall shear measurements from an omnidirectional floating element capable of simultaneously determining magnitude and …
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Near-wall velocity measurements in two-dimensional turbulent boundary layers
Significant differences involving near-wall velocity profiles in two-dimensional turbulent boundary layers when such data was plotted on law of the wall coordinates were reported by D. Coles in the Stanford Conference. These discrepancies can be especially important when near-wall velocity data is …
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Shear stresses in turbulent flow through concentric annuli
… approach to the direct measurement of wall shear stresses in fully developed turbulent flow in concentric annuli is presented. By means of a specially constructed 6 m test rig known as the 'floating sleeve', results of individual wall shear stresses, friction factors and shear stress …
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A three-dimensional turbulent boundary layer upstream and around a junction vortex flow
… placed normal to a flat surface. Measurements of wall static pressure, wall shear stress, mean velocity, and Reynolds stress tensor field are reported at several stations in the three-dimensional turbulent boundary layer region. Documentation of the flow edge conditions is provided as well as …
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2-D CFD design of the cross-sectional shape of arterial stents
… for desigining arterial stents to maximize wall shear stress is presented. A cost equation to maximize wall shear stress is derived and then inverted into a minimization problem for the optimizer. A 2-D mixed-element finite-volume scheme for solving the compressible Navier-Stokes equations …
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