A5032725002- Quantum chaos and dynamical systems
- Granular flow and fluidized beds
- Fluid Dynamics and Turbulent Flows
- Nonlinear Dynamics and Pattern Formation
- Quantum, superfluid, helium dynamics
- NMR spectroscopy and applications
- Groundwater flow and contamination studies
- Theoretical and Computational Physics
- Landslides and related hazards
- Particle Dynamics in Fluid Flows
- Fluid Dynamics and Heat Transfer
- Lattice Boltzmann Simulation Studies
- Fluid Dynamics Simulations and Interactions
- Hydraulic Fracturing and Reservoir Analysis
- Hydrocarbon exploration and reservoir analysis
- Mathematical Dynamics and Fractals
- Material Dynamics and Properties
- Chaos control and synchronization
- Spacecraft and Cryogenic Technologies
- Geophysical and Geoelectrical Methods
- Heat Transfer and Boiling Studies
- Atomic and Subatomic Physics Research
- Fluid Dynamics and Mixing
- Meteorological Phenomena and Simulations
- Microfluidic and Capillary Electrophoresis Applications
Swinburne University of Technology
2015-2024
CSIRO Manufacturing
2006-2022
Monash University
2016-2018
Virginia Tech
2017
Commonwealth Scientific and Industrial Research Organisation
2007-2016
Health Sciences and Nutrition
2012-2016
Materials Science & Engineering
2007-2014
CSIRO Oceans and Atmosphere
2014
University of California, Santa Barbara
2004
Duke University
1987-2000
This work reviews the present position of and surveys future perspectives in physics chaotic advection: field that emerged three decades ago at intersection fluid mechanics nonlinear dynamics, which encompasses a range applications with length scales ranging from micrometers to hundreds kilometers, including systems as diverse mixing thermal processing viscous fluids, microfluidics, biological flows, oceanographic atmospheric flows.
A complex Stokes flow has several cells, is subject to bifurcation, and its velocity field is, with rare exceptions, only available from numerical computations. We present experimental computational studies of two new flows: a vortex mixing multicell flows in slender cavities. develop topological relations between the geometry domain family physically realizable flows; we study bifurcations symmetries, particular reveal how forcing protocol's phase hides or reveals symmetries. Using variety...
We show that chaotic advection is inherent to flow through all types of porous media, from granular and packed media fractured open networks. The basic topological complexity gives rise dynamics under steady conditions, where fluid deformation local stagnation points imparts a 3D mechanical analog the baker's map. ubiquitous nature has significant implications for description transport, mixing, chemical reaction biological activity in media.
The integration of acoustic micromixing and single bead trapping enables the identification fluorescent signals from multiple biomarkers within minutes.
Abstract Noncohesive granular materials in slowly rotated containers mix by discrete avalanches; such a process can be described mathematically as mapping of avalanching wedges. A natural decomposition is thus proposed: geometrical part consisting wedge → , which captures large‐scale aspects the problem; dynamical confined to avalanche itself, details emanating from differences size/density/morphology. Both viewpoints are developed and comparisons with experiments used verify predictions...
Vibrated horizontally, granular material has different convection patterns from those observed for the equivalent vertical vibration. Among that develop, above onset of bulk motion, is a four roll pattern. Surface sloshing produces two smaller convective rolls lower interior rolls. Horizontal vibration creates intermittent gaps between sidewalls and heap material. Avalanches into these drives This physical mechanism in driven by As well known, can drive size segregation, we illustrate some effects.
Simple kinetic models capture the propagation and evolution of patterns produced by competing autocatalytic processes occurring in chaotic flows. Changes initial condition a few percent lead to changes final product mix 100%. This is due transport interaction along intertwining manifolds. Examples include crystallization chiral substances bistable enzyme reactions.
The aim of this work is to develop a theoretical framework for the analysis groundwater head oscillations commonly observed in bores near boundaries surface water bodies that are subject periodic variations stage height. Restricting attention linear flow equation, dynamics induced by modes acting at governed complex‐valued time‐independent equation parameterized modal frequency interest. For randomly heterogeneous aquifers hydraulic conductivity field may be regarded as spatial random...
Current diagnosis of infectious diseases such as Hendra virus (HeV) relies mostly on laboratory-based tests. There is an urgent demand for rapid technology to detect and identify these in humans animals so that disease spread can be controlled. In this study, integrated lab-on-a-chip device using a magnetic nanoparticle immunoassay developed. The key features the are chaotic fluid mixing, achieved by magnetically driven motion nanoparticles with optimal mixing protocol developed transport...
Abstract Transport and mixing of scalar quantities in fluid flows is ubiquitous industry Nature. While the more familiar turbulent promote efficient transport by their inherent spatio-temporal disorder, laminar lack such a natural mechanism far challenging. However, flow essential to many problems, insight into its characteristics great importance. Laminar transport, arguably, best described Lagrangian motion (“advection”) geometry, topology, coherence trajectories. Efficient being...
We present the results of an extensive series experiments, molecular dynamics simulations, and models that address horizontal shaking a layer granular material. The goal this work was to better understand transition between "fluid" "solid" states materials. In material-consisting glass spheres, smooth rough sand-was contained in container rectangular cross section, subjected form x=A sin(omega(t)). base porous, so it possible reduce effective weight sample by means vertical gas flow....
Abstract By using a programmed sequence of boundary motions to introduce flow reorientation steady, laminar axial in an open duct, we develop novel device investigate and exploit chaotic advection viscously dominated (low Reynolds number) flows. The design operation the Rotated Arc Mixer (RAM) is discussed. Among other things, RAM can effect good continuous mixing viscous materials without use any internal elements; moreover, has several control parameters tune advection, making it flexible...
The topological complexity inherent to all porous media imparts persistent chaotic advection under steady flow conditions, which, in concert with the no-slip boundary condition, generates anomalous transport. We explore impact of this mechanism upon longitudinal dispersion via a model random network and develop continuous-time walk that predicts both preasymptotic asymptotic In absence diffusion, ergodicity fluid orbits acts suppress from ballistic superdiffusive transport, variance scaling...
By experiments and supporting computations we investigate two methods of transport enhancement in two-dimensional open cellular flows with inertia. First, introduce a spatial dependence the velocity field by periodic modulation shape wall driving flow; this perturbs steady-state streamlines direction perpendicular to main flow. Second, time through transient acceleration–deceleration flat surprisingly, even though streamline portrait changes very little during transient, there is still...
Scalar transport in closed potential flows is investigated for the specific case of a periodically reoriented dipole flow. Despite irrotational nature flow, periodic reorientations effectively create heteroclinic and/or homoclinic points arising from joining stable and unstable manifolds. For scalar advection, Lagrangian chaos can be achieved with breakdown regular Hamiltonian structure, which governed by symmetry conditions imposed Instability envelopes associated period-doubling...
Although potential flows are irrotational, Lagrangian chaos can occur when these unsteady, with rapid global mixing observed upon flow parameter optimization. What is unknown whether in results accelerated scalar dispersion, to what magnitude, how robustly, and via mechanisms. We consider dispersion a model unsteady flow, the topology of which well understood. The asymptotic rate q corresponding distribution (strange eigenmode) calculated over space Q for Peclét numbers Pe=10{1}-10{4}....