Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 45 for “"viscous drag"”.
-
Analysis of Viscous Drag Reduction and Thermal Transport Effects for Microengineered Ultrahydrophobic Surfaces
One approach recently proposed for reducing the frictional resistance to liquid flow in microchannels is the patterning of micro-ribs and cavities on the channel walls. When treated with a hydrophobic coating, the liquid flowing in the microchannel wets only the top surfaces of the ribs, and does …
-
Deterministic and stochastic modeling of the water entry and descent of three-dimensional cylindrical bodies
… of hydrodynamic effects due to water impact, viscous drag associated with flow separation and vortex shedding, air entrainment, and realistic flow environments. Unlike existing tools that are limited to plane motions only, MINE6D captures the myriad of complex three-dimensional motions of …
-
Wedged Vortex Generator Applications for Marine Vessels
… of vortex generators (VGs) in reducing viscous drag in hydrodynamic applications. Initial experimental and computational fluid dynamics analyses identified wedge-shaped VGs as the optimal design for flow manipulation. Comparative testing of three wedge shaped VG sizes at 1.3 m/s revealed …
-
Parametric Excitation of a DWSC
… analysis and the effect of damping (especially viscous drag) on parametric excitation and instability. The thesis uses Mathieu's equation as the basis for stability analysis and time-simulates the coupled heave-sway-roll EOM. Time-domain simulation is done for two reasons: firstly for …
-
The plastic behavior of predeformed ice crystals
… dislocation viscosity results from a Snoek-type viscous drag arising from proton rearrangement in the stress field of the dislocations, as suggested by Weertman. Since the viscous drag constant at -100 C is about seven orders of magnitude greater than typical room temperature phonon drag …
-
Thermally activated dislocation motion including inertial effects in solid solutions
… The effect of thermal fluctuations and of a viscous drag on the motion of the dislocation is investigated by analogy with Brownian motion in a field of force. The rate of escape of a trapped dislocation is found to depend on the damping coefficient only for a large viscous drag. The …
-
Design, Optimization, and Testing of a Transaugmented Electromagnetic Railgun for Use as a Hydrogen Pellet Accelerator
… between short augmented railguns to minimize viscous drag. The results of the 120-$\mu$s pulse experiments suggest that a multipulsed railgun pellet injection system may be capable of accelerating solid hydrogen pellets to high velocities.
-
Capillary breakup of Discontinuously Rate Thickening Suspensions
… formation of these structures is caused by the viscous drag exerted on the filament by the oil bath. The behavior of DRTS filaments in capillary breakup was modeled with 1- dimensional approximations to momentum and mass balance equations, which are valid in the limit of slender geometry of the …
-
Approximating three-dimensional fluid flow in a microfluidic device with a two-dimensional, depth-averaged lattice Boltzmann method
… in a 2D model. In prior work in the literature, viscous drag from the top and bottom boundary surfaces omitted by the 2D simulation has been approximated and applied as an external body force acting on the fluid for the case of constant depth throughout the MFD. This work generalizes the …
-
Computational and laboratory investigations of a model of blood droplet flight for forensic applications
… di erential equations (ODEs) incorporating viscous drag and gravitational forces. We validate the model against laboratory experiments in which a mock crime scene is constructed. The experiments consist of a ballistics gel containing transfer blood or porcine blood shot by a riot ball from a …
-
Modelling the movement of superparamagnetic beads engulfed in endothelial cells
… of the affected cells is determined by the viscous drag of the medium and the amount of coupling with an externally imposed magnetic field. An efficient numerical scheme to compute the trajectories of the cells is presented as the first step in the optimal placement of a large collections of …
-
Enhanced flow boiling heat transfer in microchannels with structured surfaces at varied mass flow rates
… if a sample is too dense, there may be too much viscous drag. Thus, an optimal balance between capillary force and viscous drag must be found in order to determine the optimum micropillar array geometry and density for maximizing the critical heat flux value. Finally, for a given mass flux, the …
-
An integral method for solving the boundary-layer equations for a second-order viscoelastic liquid
… viscosity terms, there is a reduction in the viscous drag from that of Newtonian flow.
-
Design of miniature floating platform for marginal fields
… Ring Model" (DVRM) to efficiently estimate the viscous drag due to the vortex shedding of the oscillatory heave plate is presented in details. This new model DVRM combined with the standard radiation/diffraction code WAMIT is used to analyse the effect of different geometric parameters on the …
-
A feedback analysis of outer hair cell dynamics
… as cochlear amplifiers, OHCs can counteract viscous drag, generating high gain at characteristic frequencies and allowing for the sharp frequency selectivity and sensitivity observed in mammals. Excitatory displacement of the basilar membrane causes depolarization of OHC membrane potentials …
-
Flux pinning in superconducting Pb-Na
… with the results. End effects and the bulk viscous drag are considered and their effects on the model discussed. The characteristics are analysed as a function of the d.c. field and temperatureS.I. units are used throughout.
-
Theoretical and Experimental Study of a Continuous Hydrodynamically-Enhanced Separation System Paradigm
… effects combined with the dissipation due to viscous drag allows the elucidation of chaotic segregation patterns in this physically realizable three-dimensional system.
-
Theory for hydrostatic gas journal bearings for micro-electro-mechanical systems
… principles that the hydrodynamic force due to viscous drag becomes dominant with an L/D<<1 and acts in the opposite direction of the hydrodynamic force due to rotor pumping action.
-
Overview of the Skin Friction measurements on the NASA BeVERLI Hill using Oil Film Interferometry
Viscous drag reduction plays a vital role in increasing the performance of vehicles. However, there are only so many measurement techniques that can quickly and accurately measure this when compared to pressure drag measurement techniques. The current study makes use of one of the direct and robust …
-
The rheology and structure of thermotropic liquid crystalline polymers in extensional flow
… behavior. The Doi theory was evaluated with the viscous drag or rod-solvent friction term retained in the equation for the stress tensor. It was found that the Doi theory cannot predict the shear or elongational flow behavior of LCPs with parameters determined only from molecular properties. At …
Page 1 of 3