Viscosity Dependence Of Faraday Wave Formation Thresholds,
2014
California Polytechnic State University
Viscosity Dependence Of Faraday Wave Formation Thresholds, Lisa M. Slaughter
Symposium
This experiment uses an electromagnetic shaker to produce standing wave patterns on the surface of a vertically oscillating sample of silicon liquid. These surface waves, known as Faraday waves, form shapes such as squares, lines, and hexagons. They are known to be dependent upon the frequency and amplitude of the forcing as well as on the viscosity and depth of the liquid in the dish. At a depth of 4mm and for various silicon liquids having kinematic viscosities of 10, 20, and 38 cSt, we determined the acceleration at which patterns form for frequencies between 10 and 60 Hz. For …
Laser Doppler Velocimetry: Flow Measurement Using A Digital Micromirror Device,
2014
California Polytechnic State University - San Luis Obispo
Laser Doppler Velocimetry: Flow Measurement Using A Digital Micromirror Device, Dawei Kuo
Physics
In this experiment we utilize a Texas Instruments Digital Micromirror Device to impart a phase shift to the beams of a laser Doppler velocimeter. The advantages of this approach include low cost, low power consumption, a precisely known phase-stepping frequency, and the capability of working with a broad range of optical wavelengths. The velocities measured with the set up shown here are of order 1 cm/s.
Effects Of Radiation Absorption And Mass Transfer On The Free Convective Flow Passed A Vertical Flat Plate Through A Porous Medium In An Aligned Magnetic Field,
2014
Noble College
Effects Of Radiation Absorption And Mass Transfer On The Free Convective Flow Passed A Vertical Flat Plate Through A Porous Medium In An Aligned Magnetic Field, V. Manjulatha, S. V. K. Varma, V. C. C Raju
Applications and Applied Mathematics: An International Journal (AAM)
This article analyses the effects of radiation absorption and mass transfer on the steady free convective flow of a viscous, incompressible and electrically conducting fluid past an infinite vertical flat plate through a porous medium with an aligned magnetic field. Analytical solutions for concentration, temperature, and velocity are obtained by solving the governing equations in two cases namely (i) when the plate is at uniform temperature and concentration and (ii) when the plate is at constant heat and mass flux. Further the rate of mass transfer in terms of the Sherwood number, rate of heat transfer in terms of Nusselt …
Effects Of Chemical Reaction And Radiation Absorption On Mhd Flow Of Dusty Viscoelastic Fluid,
2014
University of Botswana
Effects Of Chemical Reaction And Radiation Absorption On Mhd Flow Of Dusty Viscoelastic Fluid, J. Prakash, A. G. Vijaya Kumar, M. Madhavi, S. V. K. Varma
Applications and Applied Mathematics: An International Journal (AAM)
This investigation is undertaken to study the effects of heat source and radiation absorption on unsteady hydro-magnetic heat and mass transfer flow of a dusty viscous incompressible, electrically conducting fluid between two vertical heated, porous, parallel plates in the presence of chemical reaction under the influence of a transverse applied magnetic field. Initially, the channel walls as well as the dusty fluid are assumed to be at the same temperature and the mass is assumed to be present at low level concentration so that it is constant everywhere. It is also assumed that the dusty particles are non-conducting, solid, spherical …
Mathematical Model Of Blood Flow Through A Composite Stenosis In Catheterized Artery With Permeable Wall,
2014
Integral University
Mathematical Model Of Blood Flow Through A Composite Stenosis In Catheterized Artery With Permeable Wall, Rupesh K. Srivastav
Applications and Applied Mathematics: An International Journal (AAM)
The present mathematical analysis, the study of blood flow through the model of a composite stenosed catheterized artery with permeable wall, has been performed to investigate the blood flow characteristics. The expressions for the blood flow characteristics-the impedance (resistance to flow), the wall shear stress distribution in stenosis region, the shear stress at the throat of the stenosis have been derived. The results obtained are displayed graphically and discussed briefly.
Effect Of Slip Condition On Coup Le Stress Fluid Flow In A Channel With Mild Stenosis In The Presence Of Uniform Magnetic Field,
2014
National Institute of Technology
Effect Of Slip Condition On Coup Le Stress Fluid Flow In A Channel With Mild Stenosis In The Presence Of Uniform Magnetic Field, Gurju Awgichew, G. Radhakrishnamacharya, B. Shireesha
Applications and Applied Mathematics: An International Journal (AAM)
The s teady flow of an incompressible couple stress fluid in a two dimensional uniform channel with stenosis under the influence of a magnetic field has been investigated. Assuming the stenosis to be mild, the flow equations have been analy tically solved using the slip condition and expressions for the resistance to flow and wall shear stress have been derived. The effects of various parameters on these flow variables have been studied. It is found that the resistance to flow as well as the wall shear stress increase with the height of the stenosis and decrease with the couple stress …
Modelling The Flow Of Aqueous Humor In Schlemm’S Canal In The Eye,
2014
Harcourt Butler Technological Institute
Modelling The Flow Of Aqueous Humor In Schlemm’S Canal In The Eye, Ram Avtar, Swati Srivastava, Rashmi Srivastava
Applications and Applied Mathematics: An International Journal (AAM)
A simple mathematical model for the transient flow of aqueous humor in the canal of Schlemm is developed to investigate the acceleration effects of a sudden elevation in the intraocular pressure on the flow characteristics of the aqueous humor in the canal. The model treats a canal segment as a tube of elliptic cross-section. Exact analytical solution to the model is obtained using separation of variables method. The effects of some important model parameters on the maximum and minimum shear stresses exerted on the Schlemm’s canal epithelial cells (wall) by flowing aqueous humor are investigated for the steady-state flow.
Smarticles: A Method For Identifying And Correcting Instability And Error Caused By Explicit Integration Techniques In Physically Based Simulations,
2014
California Polytechnic State University, San Luis Obispo
Smarticles: A Method For Identifying And Correcting Instability And Error Caused By Explicit Integration Techniques In Physically Based Simulations, Susan Aileen Marano
Master's Theses
Using an explicit integration method in physically based animations has many advantages including conceptual and computational simplicity, however, it re- quires small time steps to ensure low numerical instability. Simulations with large numbers of individually interacting components such as cloth, hair, and fluid models, are limited by the sections of particles most susceptible to error. This results in the need for smaller time steps than required for the majority of the system. These sections can be diverse and dynamic, quickly changing in size and location based on forces in the system. Identifying and handling these trou- blesome sections could allow …
Generalized Helicity And Beltrami Fields,
2014
Chapman University
Generalized Helicity And Beltrami Fields, Roman V. Buniy, Thomas W. Kephart
Mathematics, Physics, and Computer Science Faculty Articles and Research
We propose covariant and non-abelian generalizations of the magnetic helicity and Beltrami equation. The gauge invariance, variational principle, conserved current, energy-momentum tensor and choice of boundary conditions elucidate the subject. In particular, we prove that any extremal of the Yang-Mills action functional 1/4 f(Omega) trF(mu nu) F-mu nu d(4)x subject to the local constraint epsilon(mu nu alpha beta)trF(mu nu)F(alpha beta) = 0 satisfies the covariant non-abelian Beltrami equation.
Turbulence, Climate And Supercomputers,
2014
Jet Propulsion Laboratory, California Institute of Technology (Caltech)
Turbulence, Climate And Supercomputers, Georgios Matheou
The Transdisciplinary STEAM+ Journal
Turbulence is often referred to as the last mystery of classical physics. Although turbulence is ubiquitous and prominent in our daily lives – from the mixing of milk in a cup of coffee to the perpetual motion of the atmosphere and the resulting weather variation – our understanding of this complex phenomenon is comparatively very limited (e.g., Davidson et al., 2011).
On The Growth Rate Of Turbulent Mixing Layers: A New Parametric Model,
2014
California Polytechnic State University, San Luis Obispo
On The Growth Rate Of Turbulent Mixing Layers: A New Parametric Model, Jeffrey L. Freeman
Master's Theses
A new parametric model for the growth rate of turbulent mixing layers is proposed. A database of experimental and numerical mixing layer studies was extracted from the literature to support this effort. The domain of the model was limited to planar, spatial, nonreacting, free shear layers that were not affected by artificial mixing enhancement techniques. The model is split into two parts which were each tuned to optimally fit the database; equations for an incompressible growth rate were derived from the error function velocity profile, and a function for a compressibility factor was generalized from existing theory on the convective …
An Unexpected Particle Oscillation For Electrophoresis In Viscoelastic Fluids Through A Microchannel Constriction,
2014
Old Dominion University
An Unexpected Particle Oscillation For Electrophoresis In Viscoelastic Fluids Through A Microchannel Constriction, Xinyu Lu, Saurin Patel, Meng Zhang, Sang Woo Joo, Shizhi Qian, Amod Ogale, Xiangchun Xuan
Mechanical & Aerospace Engineering Faculty Publications
Electrophoresis plays an important role in many applications, which, however, has so far been extensively studied in Newtonian fluids only. This work presents the first experimental investigation of particle electrophoresis in viscoelastic polyethylene oxide (PEO) solutions through a microchannel constriction under pure DC electric fields. An oscillatory particle motion is observed in the constriction region, which is distinctly different from the particle behavior in a polymer-free Newtonian fluid. This stream-wise particle oscillation continues until a sufficient number of particles form a chain to pass through the constriction completely. It is speculated that such an unexpected particle oscillating phenomenon is a …
Microfluidic Electrical Sorting Of Particles Based On Shape In A Spiral Microchannel,
2014
Old Dominion University
Microfluidic Electrical Sorting Of Particles Based On Shape In A Spiral Microchannel, John Dubose, Xinyu Lu, Saurin Patel, Shizhi Qian, Sang Woo Joo
Mechanical & Aerospace Engineering Faculty Publications
Shape is an intrinsic marker of cell cycle, an important factor for identifying a bioparticle, and also a useful indicator of cell state for disease diagnostics. Therefore, shape can be a specific marker in label-free particle and cell separation for various chemical and biological applications. We demonstrate in this work a continuous-flow electrical sorting of spherical and peanut-shaped particles of similar volumes in an asymmetric double-spiral microchannel. It exploits curvature-induced dielectrophoresis to focus particles to a tight stream in the first spiral without any sheath flow and subsequently displace them to shape-dependent flow paths in the second spiral without any …
Advances In The Analysis And Prediction Of Turbulent Viscoelastic Flows,
2014
Old Dominion University
Advances In The Analysis And Prediction Of Turbulent Viscoelastic Flows, T. B. Gatski, L. Thais, G. Mompean
CCPO Publications
It has been well-known for over six decades that the addition of minute amounts of long polymer chains to organic solvents, or water, can lead to significant turbulent drag reduction. This discovery has had many practical applications such as in pipeline fluid transport, oil well operations, vehicle design and submersible vehicle projectiles, and more recently arteriosclerosis treatment. However, it has only been the last twenty-five years that the full utilization of direct numerical simulation of such turbulent viscoelastic flows has been achieved. The unique characteristics of viscoelastic fluid flow are dictated by the nonlinear differential relationship between the flow strain …
Relative Permeability Of Homogenous-Wet And Mixed-Wet Porous Media As Determined By Pore-Scale Lattice Boltzmann Modeling,
2014
Old Dominion University
Relative Permeability Of Homogenous-Wet And Mixed-Wet Porous Media As Determined By Pore-Scale Lattice Boltzmann Modeling, C. J. Landry, Z. T. Karpyn, O. Ayala
Engineering Technology Faculty Publications
We present a pore-scale study of two-phase relative permeability in homogenous-wet porous media, and porous media altered to a mixed-wet state. A Shan-Chen type multicomponent lattice Boltzmann (LB) model is employed to determine pore-scale fluid distributions and relative permeability. Mixed-wet states are created by altering the wettability of solid surfaces in contact with the nonwetting phase at the end of steady state simulation of initially homogenous-wet porous media. To ensure accurate representation of fluid-solid interfacial areas, we compare LB simulation results to experimental measurements of interfacial fluid-fluid and fluid-solid areas determined by X-ray computed microtomography imaging of water and oil …
Length Effects Of A Built-In Flapping Flat Plate On The Flow Over A Traveling Wavy Foil,
2014
Old Dominion University
Length Effects Of A Built-In Flapping Flat Plate On The Flow Over A Traveling Wavy Foil, Nansheng Liu, Yan Peng, Xiyun Lu
Mathematics & Statistics Faculty Publications
Flow over the traveling wavy foil with a built-in rigid flapping plate at its trailing edge has been numerically studied using the multi-relaxation-time Lattice Boltzmann method and immersed boundary method. The effect of the plate length on the propulsive performance such as the thrust force, energy consumption, and propeller efficiency has been investigated. Three modes (body force dominated, body and tail force competing and tail force dominated modes) have been identified that are associated with different hydrodynamics and flow structures. It is revealed that there exists a better performance plate length region and, within this region, a high propeller efficiency …
Capillary Channel Flow Experiments Aboard The International Space Station,
2013
University of Bremen
Capillary Channel Flow Experiments Aboard The International Space Station, Michael Conrath, P. J. Canfield, P. M. Bronowicki, Michael E. Dreyer, Mark M. Weislogel, A. Grah
Mechanical and Materials Engineering Faculty Publications and Presentations
In the near-weightless environment of orbiting spacecraft capillary forces dominate interfacial flow phenomena over unearthly large length scales. In current experiments aboard the International Space Station, partially open channels are being investigated to determine critical flow rate-limiting conditions above which the free surface collapses ingesting bubbles. Without the natural passive phase separating qualities of buoyancy, such ingested bubbles can in turn wreak havoc on the fluid transport systems of spacecraft. The flow channels under investigation represent geometric families of conduits with applications to liquid propellant acquisition, thermal fluids circulation, and water processing for life support. Present and near future experiments …
Asymptotic Multi-Layer Analysis Of Wind Over Unsteady Monochromatic Surface Waves,
2013
Embry-Riddle Aeronautical University
Asymptotic Multi-Layer Analysis Of Wind Over Unsteady Monochromatic Surface Waves, Shahrdad Sajjadi, Julian Hunt, Frederique Drullion
Publications
Asymptotic multi-layer analyses and computation of solutions for turbulent flows over steady and unsteady monochromatic surface wave are reviewed, in the limits of low turbulent stresses and small wave amplitude. The structure of the flow is defined in terms of asymptotically-matched thin-layers, namely the surface layer and a critical layer, whether it is ‘elevated’ or ‘immersed’, corresponding to its location above or within the surface layer. The results particularly demonstrate the physical importance of the singular flow features and physical implications of the elevated critical layer in the limit of the unsteadiness tending to zero. These agree with the variational …
Viscosity Dependence Of Faraday Wave Formation Thresholds,
2013
California Polytechnic State University - San Luis Obispo
Viscosity Dependence Of Faraday Wave Formation Thresholds, Lisa Michelle Slaughter
Physics
This experiment uses an electromagnetic shaker to produce standing wave patterns on the surface of a vertically oscillating sample of silicon liquid. These surface waves, known as Faraday waves, form shapes such as squares, lines, and hexagons. They are known to be dependent upon the frequency and amplitude of the forcing as well as on the viscosity and depth of the liquid in the dish. At a depth of 4mm and for various silicon liquids having kinematic viscosities of 10, 20, and 38 cSt, we determined the acceleration at which patterns form for frequencies between 10 and 60 Hz. For …
Dispersion Of A Solute In Hartmann Two-Fluid Flow Between Two Parallel Plates,
2013
Gulbarga University
Dispersion Of A Solute In Hartmann Two-Fluid Flow Between Two Parallel Plates, J. P. Kumar, J. C. Umavathi
Applications and Applied Mathematics: An International Journal (AAM)
The paper presents an analytical solution for the dispersion of a solute in a conducting immiscible fluid flowing between two parallel plates in the presence of a transverse magnetic field. The fluids in both the regions are incompressible, electrically conducting and the transport properties are assumed to be constant. The channel walls are assumed to be electrically insulating. Separate solutions for each fluid are obtained and these solutions are matched at the interface using suitable matching conditions. The results are tabulated for various values of viscosity ratio, pressure gradient and Hartman number on the effective Taylor dispersion coefficient and volumetric …
