ORCID Profile
0000-0002-5649-4180
Current Organisation
Monash University
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Resources Engineering and Extractive Metallurgy | Mineral Processing | Interdisciplinary Engineering | Theoretical and Applied Mechanics | Wastewater Treatment Processes | Nanotechnology | Geophysics | Colloid And Surface Chemistry | Powder and Particle Technology | Fluidization And Fluid Mechanics | Numerical Analysis | Heat And Mass Transfer Operations | Turbulent Flows | Chemical Engineering | Chemical Engineering Not Elsewhere Classified | Pyrometallurgy | Mineral processing/beneficiation | Physical Oceanography | Geophysical Fluid Dynamics | Turbulent Flows | Chemical engineering | Mineral Processing/Beneficiation | Computational Fluid Dynamics | Pyrometallurgy | Membrane And Separation Technologies | Powder and particle technology | Fluid Physics
ANZSRC Socio-Economic Objective (SEO)
Land and water management | Primary mining and extraction processes | Expanding Knowledge in Engineering | Management of Water Consumption by Mineral Resource Activities | Industry | Management of Greenhouse Gas Emissions from Transport Activities | Industrial instrumentation | Medical instrumentation | Scientific instrumentation | Concentrating processes of other base metal ores | Urban and Industrial Water Management | Industrial Energy Conservation and Efficiency | Basic Iron and Steel Products | Expanding Knowledge in the Earth Sciences | Mining and Extraction of Iron Ores | Alumina Production |
Related Links
Publications
The ventricular residence time distribution derived from 4D flow particle tracing: a novel marker of myocardial dysfunction
Publisher: Springer Science and Business Media LLC
Date: 27-06-2018
DOI: 10.1007/S10554-018-1407-0
Abstract: 4D flow cardiac magnetic resonance (CMR) imaging allows visualisation of blood flow in the cardiac chambers and great vessels. Post processing of the flow data allows determination of the residence time distribution (RTD), a novel means of assessing ventricular function, potentially providing additional information beyond ejection fraction. We evaluated the RTD measurement of efficiency of left and right ventricular (LV and RV) blood flow. 16 volunteers and 16 patients with systolic dysfunction (LVEF < 50%) underwent CMR studies including 4D flow. The RTDs were created computationally by seeding virtual 'particles' at the inlet plane in customised post-processing software, moving these particles with the measured blood velocity, recording and counting how many exited per unit of time. The efficiency of ventricular flow was determined from the RTDs based on the time constant (RTDc = - 1/B) of the exponential decay. The RTDc was compared to ejection fraction, T1 mapping and global longitudinal strain (GLS). There was a significant difference between groups in LV RTDc (healthy volunteers 1.2 ± 0.13 vs systolic dysfunction 2.2 ± 0.80, p < 0.001, C-statistic = 1.0) and RV RTDc (1.5 ± 0.15 vs 2.0 ± 0.57, p = 0.013, C-statistic = 0.799). The LV RTDc correlated significantly with LVEF (R = - 0.84, P < 0.001) and the RV RTDc had significant correlation with RVEF (R = - 0.402, p = 0.008). The correlation between LV RTDc and LVEF was similar to GLS and LVEF (0.926, p < 0.001). The ventricular residence time correlates with ejection fraction and can distinguish normal from abnormal systolic function. Further assessment of this method of assessment of chamber function is warranted.
Rogue wave impact on a tension leg platform: the effect of wave incidence angle and mooring line tension
Publisher: Elsevier BV
Date: 03-2013
Modelling thin films of truncated power-law fluids between bubbles and surfaces
Publisher: Elsevier BV
Date: 02-2023
A numerical approach for simulating flow through thin porous media
Publisher: Elsevier BV
Date: 09-2017
Low Reynolds number scalar transport enhancement in viscous and non-Newtonian fluids
Publisher: Elsevier BV
Date: 2009
Particle transport in a bottom-feed separation vessel
Publisher: Elsevier BV
Date: 12-1998
Experimental validation of a 1-D continuous thickening model using a pilot column
Publisher: Elsevier BV
Date: 07-2010
Modelling elastoplastic frictional collisions of ellipsoidal granules with collisional-SPH
Publisher: Elsevier BV
Date: 06-2023
Lagrangian Transport and Chaotic Advection in Three-Dimensional Laminar Flows
Publisher: ASME International
Date: 28-04-2021
DOI: 10.1115/1.4050701
Abstract: Transport and mixing of scalar quantities in fluid flows is ubiquitous in industry and Nature. While the more familiar turbulent flows promote efficient transport and mixing by their inherent spatio-temporal disorder, laminar flows lack such a natural mixing mechanism and efficient transport is far more challenging. However, laminar flow is essential to many problems, and insight into its transport characteristics of great importance. Laminar transport, arguably, is best described by the Lagrangian fluid motion (“advection”) and the geometry, topology, and coherence of fluid trajectories. Efficient laminar transport being equivalent to “chaotic advection” is a key finding of this approach. The Lagrangian framework enables systematic analysis and design of laminar flows. However, the gap between scientific insights into Lagrangian transport and technological applications is formidable primarily for two reasons. First, many studies concern two-dimensional (2D) flows, yet the real world is three-dimensional (3D). Second, Lagrangian transport is typically investigated for idealized flows, yet practical relevance requires studies on realistic 3D flows. The present review aims to stimulate further development and utilization of know-how on 3D Lagrangian transport and its dissemination to practice. To this end, 3D practical flows are categorized into canonical problems. First, to expose the ersity of Lagrangian transport and create awareness of its broad relevance. Second, to enable knowledge transfer both within and between scientific disciplines. Third, to reconcile practical flows with fundamentals on Lagrangian transport and chaotic advection. This may be a first incentive to structurally integrate the “Lagrangian mindset” into the analysis and design of 3D practical flows.
An SPH Projection Method
Publisher: Elsevier BV
Date: 07-1999
A volume of fluid (VOF) method for the simulation of metallurgical flows
Publisher: Iron and Steel Institute of Japan
Date: 2001
A parametric study of droplet deformation through a microfluidic contraction: Low viscosity Newtonian droplets
Publisher: Elsevier BV
Date: 08-2006
Flow regime analysis of non-Newtonian duct flows
Publisher: AIP Publishing
Date: 2006
DOI: 10.1063/1.2163913
Abstract: Reoriented duct flows of generalized Newtonian fluids are an idealization of non-Newtonian fluid flow in industrial in-line mixers. Based on scaling analysis and computation we find that non-Newtonian duct flows have several limit behaviors, in the sense that such flows can become (nearly) independent of one or more of the rheological and dynamical control parameters, simplifying the general flow and mixing problem. These limit flows give several levels of modeling complexity to the full problem of non-Newtonian duct flow. We describe the sets of simplified flow models and their corresponding regions of validity. This flow-model decomposition captures the essential rheological and dynamical characteristics of the reoriented duct flows and enables a more efficient and systematic study and design of flow and mixing of non-Newtonian fluids in ducts. Key aspects of the flow-model decomposition are demonstrated via a specific, but representative, duct flow.
Mixing and particle dispersion in the wavy vortex regime of Taylor-Couette flow
Publisher: Wiley
Date: 05-1998
Turbulent coarse-particle suspension flow: Measurement and modelling
Publisher: Elsevier BV
Date: 08-2020
Assessing atrial myopathy with cardiac magnetic resonance imaging in embolic stroke of undetermined source
Publisher: Elsevier BV
Date: 10-2023
A parametric study of droplet deformation through a microfluidic contraction: Shear thinning liquids
Publisher: Elsevier BV
Date: 05-2007
High concentration suspension pumping
Publisher: Elsevier BV
Date: 04-2006
Localized shear generates three-dimensional transport
Publisher: AIP Publishing
Date: 04-2017
DOI: 10.1063/1.4979666
Abstract: Understanding the mechanisms that control three-dimensional (3D) fluid transport is central to many processes, including mixing, chemical reaction, and biological activity. Here a novel mechanism for 3D transport is uncovered where fluid particles are kicked between streamlines near a localized shear, which occurs in many flows and materials. This results in 3D transport similar to Resonance Induced Dispersion (RID) however, this new mechanism is more rapid and mutually incompatible with RID. We explore its governing impact with both an abstract 2-action flow and a model fluid flow. We show that transitions from one-dimensional (1D) to two-dimensional (2D) and 2D to 3D transport occur based on the relative magnitudes of streamline jumps in two transverse directions.
An analysis of parasitic current generation in Volume of Fluid simulations
Publisher: Elsevier BV
Date: 10-2006
Collisional SPH: A method to model frictional collisions with SPH
Publisher: Elsevier BV
Date: 06-2021
Predicting chaotic dispersion with Eulerian symmetry measures: Wavy Taylor-vortex flow
Publisher: AIP Publishing
Date: 09-2001
DOI: 10.1063/1.1387471
Abstract: In a recent investigation of particle transport in numerically computed wavy Taylor-vortex flow, Rudman estimated an effective axial diffusion coefficient, Dz, to characterize the enhanced mixing due to chaotic advection [AIChE J. 44, 1015 (1998)]. We find that Dz is proportional to the product of two measures of symmetry deviation. The first is a measure of the average deviation of the flow from rotational symmetry, and the second is a measure of the average deviation from flexion-free flow (a flow where the curl of the vorticity is zero). Because these quantities are obtained directly from the velocity field, we call them Eulerian symmetry measures. Thus, we show that the macroscopic transport behavior in a flow can be quantified directly in terms of the velocity field and its gradients, and hence provides a connection between Eulerian and Lagrangian pictures of transport—a problem of fundamental and widespread interest.
Volume-tracking methods for interfacial flow calculations
Publisher: Wiley
Date: 15-04-1997
DOI: 10.1002/(SICI)1097-0363(19970415)24:7<671::AID-FLD508>3.0.CO;2-9
Turbulent coarse-particle non-Newtonian suspension flow in a pipe
Publisher: Elsevier BV
Date: 09-2021
Nonmixing vortex cores in wavy Taylor vortex flow
Publisher: AIP Publishing
Date: 06-2008
DOI: 10.1063/1.2937726
Abstract: When the symmetry of axisymmetric Taylor vortex flow is broken, time-periodic wavy vortex flow (WVF) appears and quite quickly becomes globally chaotic (in the Lagrangian sense) with increasing Reynolds number. Previously published simulations of WVF suggest that beyond a certain Re, nonmixing vortex cores reappear in the flow and grow in size with further increases in Re. This reappearance occurs well into the inertia-dominated flow regime and coincides with a decrease in axial fluid dispersion and an increase in flow symmetry as measured by certain Eulerian symmetry measures. In this brief paper, we present experimental dye-reaction visualization results from two WVF wave states in the region where vortex cores are predicted numerically. The experimental results show unambiguous visual evidence for the existence of vortex cores and provide visual agreement with the numerical results. They are significant in that experimental evidence for these structures in WVF has not been reported before. The results also suggest that vortex-to-vortex transport occurs via sheetlike structures that are pulled from one vortex to another and become wrapped around the vortex cores before being stretched to the point at which molecular diffusion dominates.
An experimental and theoretical study of the mixing characteristics of a periodically reoriented irrotational flow
Publisher: The Royal Society
Date: 13-05-2010
Abstract: The minimum-energy method to generate chaotic advection should be to use an irrotational flow. However, irrotational flows have no saddle connections to perturb in order to generate chaotic orbits. To the early work of Jones & Aref (Jones & Aref 1988 Phys. Fluids 31 , 469–485 ( doi:10.1063/1.866828 )) on potential flow chaos, we add periodic reorientation to generate chaotic advection with irrotational experimental flows. Our experimental irrotational flow is a dipole potential flow in a disc-shaped Hele-Shaw cell called the rotated potential mixing flow it leads to chaotic advection and transport in the disc. We derive an analytical map for the flow. This is a partially open flow, in which parts of the flow remain in the cell forever, and parts of it pass through with residence-time and exit-time distributions that have self-similar features in the control parameter space of the stirring. The theory compares well with the experiment.
Effect of Shear on Particulate Suspension Dewatering
Publisher: Elsevier BV
Date: 07-2005
DOI: 10.1205/CHERD.04328
Dense non‐Newtonian suspension flow: Effect of solids properties and pipe size
Publisher: Wiley
Date: 25-03-2022
DOI: 10.1002/AIC.17690
Abstract: High concentration tailings transport is a promising approach for improving the safety and environmental impact of mining tailings disposal. High concentration suspensions exhibit complex non‐Newtonian behavior. The interaction between the non‐Newtonian carrier and the coarse particles is still poorly understood, particularly in the turbulent regime. This article considers the effect of solids concentration, particle and pipe size on transport characteristics in a weakly turbulent non‐Newtonian suspension using a DNS‐DEM methodology. Heterogeneous flow and a sliding bed are presented in the turbulent regime, with particles being more suspended in a small pipe. Although stratification is observed, there is no “packed” bed predicted for these cases. The presence of the viscous core region contributes to the dominance of the drag force in the central region in a non‐Newtonian suspension. Non‐Newtonian suspensions can also be transported at a much lower velocity and display a comparable specific energy consumption to a conventional dilute suspension.
Flow visualisation and computational prediction in thickener rake models
Publisher: Elsevier BV
Date: 02-2003
Global parametric solutions of scalar transport
Publisher: Elsevier BV
Date: 03-2008
Scalar dispersion in a periodically reoriented potential flow: Acceleration via Lagrangian chaos
Publisher: American Physical Society (APS)
Date: 29-04-2010
Global organization of three-dimensional, volume-preserving flows: Constraints, degenerate points, and Lagrangian structure
Publisher: AIP Publishing
Date: 03-2020
DOI: 10.1063/1.5135333
Abstract: Global organization of three-dimensional (3D) Lagrangian chaotic transport is difficult to infer without extensive computation. For 3D time-periodic flows with one invariant, we show how constraints on deformation that arise from volume-preservation and periodic lines result in resonant degenerate points that periodically have zero net deformation. These points organize all Lagrangian transport in such flows through coordination of lower-order and higher-order periodic lines and prefigure unique transport structures that arise after perturbation and breaking of the invariant. Degenerate points of periodic lines and the extended 3D structures associated with them are easily identified through the trace of the deformation tensor calculated along periodic lines. These results reveal the importance of degenerate points in understanding transport in one-invariant fluid flows.
Composing chaos: An experimental and numerical study of an open duct mixing flow
Publisher: Wiley
Date: 19-09-2006
DOI: 10.1002/AIC.10640
Numerical modelling of free surface flows in metallurgical vessels
Publisher: Elsevier BV
Date: 02-2002
Control mechanisms for the global structure of scalar dispersion in chaotic flows
Publisher: American Physical Society (APS)
Date: 14-08-2014
ASSESSMENT OF HIGHER-ORDER UPWIND SCHEMES INCORPORATING FCT FOR CONVECTION-DOMINATEDPROBLEMS
Publisher: Informa UK Limited
Date: 1995
A DNS investigation of non-Newtonian turbulent open channel flow
Publisher: AIP
Date: 2010
DOI: 10.1063/1.3464856
Flow and Axial Dispersion Simulation for Traveling Axisymmetric Taylor Vortices
Publisher: Wiley
Date: 02-1998
Application of SPH to single and multiphase geophysical, biophysical and industrial fluid flows
Publisher: Informa UK Limited
Date: 16-11-2020
An investigation of the flow regimes resulting from splashing drops
Publisher: AIP Publishing
Date: 04-2000
DOI: 10.1063/1.870332
Abstract: Numerical simulations have been used to investigate the flow regimes resulting from the impact of a 2.9 mm water drop on a deep water pool at velocities in the range 0.8–2.5 m/s. The results were used to identify the conditions leading to the formation of vortex rings, entrapment of a bubble during cavity collapse and the formation of vertical Rayleigh jets. Bubble entrapment and the associated growth of a thin high speed jet were shown to be the result of a capillary wave that propagates down the walls of the crater resulting from drop impact. Although the existence of a capillary waves is a necessary condition for bubble entrapment, bubbles will only occur when the wave speed and maximum crater size is such that the wave reaches the bottom of the crater before collapse has resulted in the formation of a thick Rayleigh jet. Simulations also clarified the conditions for which drop impact leads to axi-symmetric vortex rings. Results not reported previously, include the observation that a single drop can produce multiple vortex rings and that vortex rings can occur for conditions that lead to broad Rayleigh jets. Based on these results, it was concluded that the formation of vortex rings depends on the time at which vorticity is generated and the nature of its subsequent transport.
The influence of shear-dependent rheology on turbulent pipe flow
Publisher: Cambridge University Press (CUP)
Date: 08-06-2017
DOI: 10.1017/JFM.2017.296
Abstract: Direct numerical simulations of turbulent pipe flow of power-law fluids at $Re_{\\unicode[STIX]{x1D70F}}=323$ are analysed in order to understand the way in which shear thinning or thickening affects first- and second-order flow statistics including turbulent kinetic energy production, transport and dissipation in such flows. The results show that with shear thinning, near-wall streaks become weaker and the axial and azimuthal correlation lengths of axial velocity fluctuations increase. Viscosity fluctuations give rise to an additional shear stress term in the mean momentum equation which is negative for shear-thinning fluids and which increases in magnitude as the fluid becomes more shear thinning: for an equal mean wall shear stress, this term increases the mean velocity gradient in shear-thinning fluids when compared to a Newtonian fluid. Consequently, the mean velocity profile in power-law fluids deviates from the law of the wall $U_{z}^{+}=y^{+}$ in the viscous sublayer when traditional near-wall scaling is used. Consideration is briefly given to an alternative scaling that allows the law of wall to be recovered but which results in loss of a common mean stress profile. With shear thinning, the mean viscosity increases slightly at the wall and its profile appears to be approximately logarithmic in the velocity log layer. Through analysis of the turbulent kinetic energy budget, undertaken here for the first time for generalised Newtonian fluids, it is shown that shear thinning decreases the overall turbulent kinetic energy production but widens the wall-normal region where it is generated. Additional dissipation terms in the mean flow and turbulent kinetic energy budget equations arise from viscosity fluctuations with shear thinning, these result in a net decrease in the total viscous dissipation. The overall effect of shear thinning on the turbulent kinetic energy budget is found to be largely confined to the inner layers, $y^{+}\\lesssim 60$ .
Exact solutions of the Navier-Stokes equations generalized for flow in porous media
Publisher: Springer Science and Business Media LLC
Date: 05-2018
Comparative study on the accuracy and stability of SPH schemes in simulating energetic free-surface flows
Publisher: Elsevier BV
Date: 11-2012
Application of immersed boundary methods to non-Newtonian yield-pseudoplastic flows
Publisher: Elsevier BV
Date: 12-2023
On the coupling of direct numerical simulation and resolvent analysis
Publisher: Springer International Publishing
Date: 2016
Chaotic diffusion in steady wavy vortex flow—Dependence on wave state and correlation with Eulerian symmetry measures
Publisher: IOP Publishing
Date: 2008
Predicting Rebound of Ellipsoidal Granules Using SPH
Publisher: Springer Singapore
Date: 2021
Large scale simulation of industrial, engineering and geophysical flows using particle methods
Publisher: Springer Netherlands
Date: 2011
Bifurcations and degenerate periodic points in a three dimensional chaotic fluid flow
Publisher: AIP Publishing
Date: 05-2016
DOI: 10.1063/1.4950763
Abstract: Analysis of the periodic points of a conservative periodic dynamical system uncovers the basic kinematic structure of the transport dynamics and identifies regions of local stability or chaos. While elliptic and hyperbolic points typically govern such behaviour in 3D systems, degenerate (parabolic) points also play an important role. These points represent a bifurcation in local stability and Lagrangian topology. In this study, we consider the ramifications of the two types of degenerate periodic points that occur in a model 3D fluid flow. (1) Period-tripling bifurcations occur when the local rotation angle associated with elliptic points is reversed, creating a reversal in the orientation of associated Lagrangian structures. Even though a single unstable point is created, the bifurcation in local stability has a large influence on local transport and the global arrangement of manifolds as the unstable degenerate point has three stable and three unstable directions, similar to hyperbolic points, and occurs at the intersection of three hyperbolic periodic lines. The presence of period-tripling bifurcation points indicates regions of both chaos and confinement, with the extent of each depending on the nature of the associated manifold intersections. (2) The second type of bifurcation occurs when periodic lines become tangent to local or global invariant surfaces. This bifurcation creates both saddle–centre bifurcations which can create both chaotic and stable regions, and period-doubling bifurcations which are a common route to chaos in 2D systems. We provide conditions for the occurrence of these tangent bifurcations in 3D conservative systems, as well as constraints on the possible types of tangent bifurcation that can occur based on topological considerations.
One-field equations for two-phase flows
Publisher: Cambridge University Press (CUP)
Date: 10-1997
DOI: 10.1017/S033427000000878X
Abstract: A new derivation of the averaged heat and mass transport equations for two-phase flows is presented. A volume averaging technique is used in which averaging is perform over both phases simultaneously in order to derive equations that describe transport the mixture, rather than transport in each phase. The derivation is particularly applicable to incompressible liquid/solid systems in which the two phases are tightly coupled. An ex le of the numerical solution of the equations is then presented in which a thermally convecting suspension is modelled. It is seen that large-scale instability can result from the interaction of thermal and compositional density gradients.
Direct numerical simulation of turbulent non-Newtonian flow using a spectral element method
Publisher: Elsevier BV
Date: 11-2006
A DNS investigation of the effect of yield stress for turbulent non-newtonian suspension flow in open channels
Publisher: Informa UK Limited
Date: 21-04-2011
Recent developments in techniques and methodologies for improving thickener performance
Publisher: Elsevier BV
Date: 12-2000
Extreme wave interaction with a floating oil rig: Prediction using SPH
Publisher: Inderscience Publishers
Date: 2009
Turbulent pipe flow of shear-thinning fluids
Publisher: Elsevier BV
Date: 03-2004
A reduced-order model of three-dimensional unsteady flow in a cavity based on the resolvent operator
Publisher: Cambridge University Press (CUP)
Date: 08-06-2016
DOI: 10.1017/JFM.2016.339
Abstract: A novel reduced-order model for time-varying nonlinear flows arising from a resolvent decomposition based on the time-mean flow is proposed. The inputs required for the model are the mean-flow field and a small set of velocity time-series data obtained at isolated measurement points, which are used to fix relevant frequencies, litudes and phases of a limited number of resolvent modes that, together with the mean flow, constitute the reduced-order model. The technique is applied to derive a model for the unsteady three-dimensional flow in a lid-driven cavity at a Reynolds number of 1200 that is based on the two-dimensional mean flow, three resolvent modes selected at the most active spanwise wavenumber, and either one or two velocity probe signals. The least-squares full-field error of the reconstructed velocity obtained using the model and two point velocity probes is of the order of 5 % of the lid velocity, and the dynamical behaviour of the reconstructed flow is qualitatively similar to that of the complete flow.
A hybrid method for simulation of axial flow impeller driven mixing vessels
Publisher: Elsevier BV
Date: 09-2000
A 3D unsplit-advection volume tracking algorithm with planarity-preserving interface reconstruction
Publisher: Elsevier BV
Date: 12-2006
Impact of discontinuous deformation upon the rate of chaotic mixing
Publisher: American Physical Society (APS)
Date: 21-02-2017
VOLUME-OF-FLUID CALCULATION OF HEAT OR MASS TRANSFER ACROSS DEFORMING INTERFACES IN TWO-FLUID FLOW
Publisher: Informa UK Limited
Date: 03-2002
The feedback loop in impinging two-dimensional high-subsonic and supersonic jets
Publisher: Elsevier BV
Date: 02-1996
SPH modelling of multi-fluid lock-exchange over and within porous media
Publisher: Elsevier BV
Date: 10-2017
Macroscopic dynamics of flocculated colloidal suspensions
Publisher: Elsevier BV
Date: 12-2010
Smoothed Particle Hydrodynamics modelling of fresh and salt water dynamics in porous media
Publisher: Elsevier BV
Date: 09-2019
Two-phase natural convection: implications for crystal settling in magma chambers
Publisher: Elsevier BV
Date: 08-1992
Experimental and numerical comparisons of the break-up of a large bubble
Publisher: Springer Science and Business Media LLC
Date: 04-05-1999
Centrifugal pump performance calculation for homogeneous suspensions
Publisher: Wiley
Date: 28-07-2009
DOI: 10.1002/CJCE.20192
The flow of non-newtonian fluids down inclines
Publisher: Elsevier BV
Date: 06-2006
Topological mixing study of non-Newtonian duct flows
Publisher: AIP Publishing
Date: 10-2006
DOI: 10.1063/1.2359698
Abstract: Tracer advection of non-Newtonian fluids in reoriented duct flows is investigated in terms of coherent structures in the web of tracer paths that determine transport properties geometrically. Reoriented duct flows are an idealization of in-line mixers, encompassing many micro and industrial continuous mixers. The topology of the tracer dynamics of reoriented duct flows is Hamiltonian. As the stretching per reorientation increases from zero, we show that the qualitative route from the integrable state to global chaos and good mixing does not depend on fluid rheology. This is due to a universal symmetry of reoriented duct flows, which we derive, controlling the topology of the tracer web. Symmetry determines where in parameter space global chaos first occurs, while increasing non-Newtonian effects delays the quantitative value of onset. Theory is demonstrated computationally for a representative duct flow, the rotated arc mixing flow.
Generating stable solitary waves with a piston-type wavemaker
Publisher: Elsevier BV
Date: 04-2020
Solitary Wave Interaction With Vertical Porous Barriers
Publisher: American Society of Mechanical Engineers
Date: 09-06-2019
Abstract: Tsunami waves pose a threat to the coastal zone and numerous studies have been carried out in the past to understand them. The present study — carried out in the 2D wave flume at the Ocean Engineering Laboratory of IIT Bombay — focusses on the interaction and run-up of solitary waves on coastal protection structures in the form of thin, rigid vertical porous barriers with special attention given to the degree of energy dissipation. In order to understand the physics of the energy dissipation problem, the propagation of the solitary wave and its interaction with the porous barrier has been studied from the viewpoint of energy balance. Based on this, a proper relationship for the wave energy dissipated by the barrier has been developed. Using this relationship, the experimental data has been analyzed and we have determined that the plate porosity that gives the optimal energy dissipation characteristics lies within the 10–20% range. In addition, using the experimental data, we have derived a formula for calculating the maximum wave run-up on the porous barrier models which should be useful in the planning, design, construction and maintenance of coastal protection structures.
Simulation of the near field of a jet in a cross flow
Publisher: Elsevier BV
Date: 02-1996
Raking in gravity thickeners
Publisher: Elsevier BV
Date: 03-2008
The linear stability of swirling vortex rings
Publisher: AIP Publishing
Date: 11-2016
DOI: 10.1063/1.4967732
Abstract: The stability of vortex rings with an azimuthal component of velocity is investigated numerically for various combinations of ring wavenumber and swirl magnitude. The vortex rings are equilibrated from an initially Gaussian distribution of azimuthal vorticity and azimuthal velocity, at a circulation-based Reynolds number of 10 000, to a state in which the vortex core is qualitatively identical to that of the piston generated vortex rings. The instability modes of these rings can be characterised as Kelvin instability modes, analogous to instability modes observed for Gaussian and Batchelor vortex pairs. The shape of an lified mode typically depends only on the azimuthal wavenumber at the centre of the vortex core and the magnitude of the corresponding velocity component. The wavenumber of a particular sinuous instability varies with radius from the vortex ring centre for rings of finite aspect ratio. Thicker rings spread the lification over a wider range of wavenumbers for a particular resonant mode pair, while the growth rate and the azimuthal wavenumber corresponding to the peak growth both vary as a function of the wavenumber variation. Normalisation of the wavenumber and the growth rate by a measure of the wavenumber variation allows a coherent description of stability modes to be proposed, across the parameter space. These results provide a framework for predicting the development of resonant Kelvin instabilities on vortex rings with an induced component of swirling velocity.
On the origin of frequency sparsity in direct numerical simulations of turbulent pipe flow
Publisher: AIP Publishing
Date: 10-2014
DOI: 10.1063/1.4900768
Abstract: The possibility of creating reduced-order models for canonical wall-bounded turbulent flows based on exploiting energy sparsity in frequency domain, as proposed by Bourguignon et al. [Phys. Fluids 26, 015109 (2014)], is examined. The present letter explains the origins of energetically sparse dominant frequencies and provides fundamental information for the design of such reduced-order models. The resolvent decomposition of a pipe flow is employed to consider the influence of finite domain length on the flow dynamics, which acts as a restriction on the possible wavespeeds in the flow. A forcing-to-fluctuation gain analysis in the frequency domain reveals that large sparse peaks in lification occur when one of the possible wavespeeds matches the local wavespeed via the critical layer mechanism. A link between lification and energy is provided through the similar characteristics exhibited by the most energetically relevant flow structures, arising from a dynamic mode decomposition of direct numerical simulation data, and the resolvent modes associated with the most lified sparse frequencies. These results support the feasibility of reduced-order models based on the selection of the most lified modes emerging from the resolvent model, leading to a novel computationally efficient method of representing turbulent flows.
Rogue Wave Impact on a Semi-Submersible Offshore Platform
Publisher: ASMEDC
Date: 2008
Abstract: Full three-dimensional simulation of the impact of a rogue wave on a semi-submersible platform is undertaken using the Smoothed Particle Hydrodynamics (SPH) technique. Two different mooring configurations are considered: A Tension Leg Platform (TLP) system and a Taut Spread Mooring (TSM) system. It is seen that for a wave impact normal to the platform side, the heave and surge responses of the platform are significantly different for the two mooring systems. The TLP system undergoes large surge but comparatively smaller heave motions than the TSM system. The degree of pitch is very similar. The total tension in the mooring cables is approximately four times higher in the TSM system and exceeds the strength of the cables used in the simulation. SPH is seen to be an attractive alternative to standard methods for simulating the coupled interaction of highly non-linear breaking waves and structural motion.
Measuring atrial stasis during sinus rhythm in patients with paroxysmal atrial fibrillation using 4 Dimensional flow imaging
Publisher: Elsevier BV
Date: 09-2020
Complete parametric scalar dispersion
Publisher: SPIE
Date: 21-12-2008
DOI: 10.1117/12.769348
Temperature and strain rate effects in cold spray investigated by smoothed particle hydrodynamics
Publisher: Elsevier BV
Date: 09-2014
Streamwise-varying steady transpiration control in turbulent pipe flow
Publisher: Cambridge University Press (CUP)
Date: 19-05-2016
DOI: 10.1017/JFM.2016.279
Abstract: The effect of streamwise-varying steady transpiration on turbulent pipe flow is examined using direct numerical simulation at fixed friction Reynolds number $\\mathit{Re}_{{\\it\\tau}}=314$ . The streamwise momentum equation reveals three physical mechanisms caused by transpiration acting in the flow: modification of Reynolds shear stress, steady streaming and generation of non-zero mean streamwise gradients. The influence of these mechanisms has been examined by means of a parameter sweep involving transpiration litude and wavelength. The observed trends have permitted identification of wall transpiration configurations able to reduce or increase the overall flow rate $-36.1\\,\\%$ and $19.3\\,\\%$ , respectively. Energetics associated with these modifications are presented. A novel resolvent formulation has been developed to investigate the dynamics of pipe flows with a constant cross-section but with time-mean spatial periodicity induced by changes in boundary conditions. This formulation, based on a triple decomposition, paves the way for understanding turbulence in such flows using only the mean velocity profile. Resolvent analysis based on the time-mean flow and dynamic mode decomposition based on simulation data snapshots have both been used to obtain a description of the reorganization of the flow structures caused by the transpiration. We show that the pipe flows dynamics are dominated by a critical-layer mechanism and the waviness induced in the flow structures plays a role on the streamwise momentum balance by generating additional terms.
The effect of shear on gravity thickening: Pilot scale modelling
Publisher: Elsevier BV
Date: 07-2010
Efficiency of raking in gravity thickeners
Publisher: Elsevier BV
Date: 07-2010
Direct numerical simulation of turbulent non-Newtonian flow using OpenFOAM
Publisher: Elsevier BV
Date: 08-2019
Elastoplastic frictional collisions with Collisional-SPH
Publisher: Elsevier BV
Date: 04-2022
The separate roles of shear rate and mixing on gibbsite precipitation
Publisher: Elsevier BV
Date: 04-2001
Lagrangian topology of a periodically reoriented potential flow: Symmetry, optimization, and mixing
Publisher: American Physical Society (APS)
Date: 21-09-2009
Mixing of discontinuously deforming media
Publisher: AIP Publishing
Date: 02-2016
DOI: 10.1063/1.4941851
Abstract: Mixing of materials is fundamental to many natural phenomena and engineering applications. The presence of discontinuous deformations—such as shear banding or wall slip—creates new mechanisms for mixing and transport beyond those predicted by classical dynamical systems theory. Here, we show how a novel mixing mechanism combining stretching with cutting and shuffling yields exponential mixing rates, quantified by a positive Lyapunov exponent, an impossibility for systems with cutting and shuffling alone or bounded systems with stretching alone, and demonstrate it in a fluid flow. While dynamical systems theory provides a framework for understanding mixing in smoothly deforming media, a theory of discontinuous mixing is yet to be fully developed. New methods are needed to systematize, explain, and extrapolate measurements on systems with discontinuous deformations. Here, we investigate “webs” of Lagrangian discontinuities and show that they provide a template for the overall transport dynamics. Considering slip deformations as the asymptotic limit of increasingly localised smooth shear, we also demonstrate exactly how some of the new structures introduced by discontinuous deformations are analogous to structures in smoothly deforming systems.
Influence of volume and aspect ratio of liquid bridges on capillary breakup rheometry
Publisher: AIP Publishing
Date: 03-2022
DOI: 10.1063/5.0084878
Abstract: Capillary thinning of liquid bridges is routinely used for extensional rheology of Newtonian and complex fluids. Although it is expected that the volume and aspect ratio of a liquid bridge significantly influence its dynamics, the role played by these parameters in rheological characterization has not been previously studied. We perform numerical simulations of Newtonian as well as viscoelastic liquid bridges with the one-dimensional slender-filament approximation of Eggers and Dupont [“Drop formation in a one-dimensional approximation of the Navier–Stokes equation,” J. Fluid Mech. 262, 205–221 (1994)] and Ardekani et al. [“Dynamics of bead formation, filament thinning and breakup in weakly viscoelastic jets,” J. Fluid Mech. 665, 46–56 (2010)]. S le volume and bridge aspect ratio control two phenomena that can adversely impact rheological characterization: the tendency to form satellite drops at the necking plane and the slowing down of capillary thinning due to the proximity (in parameter space) of the liquid-bridge stability boundary. The optimal range of these parameter values to avoid drop formation and slowdown is discussed.
Analytical modeling and numerical simulation of forces in an endoluminal graft
Publisher: International Society of Endovascular Specialists
Date: 08-2001
The influence of mooring system in rogue wave impact on an offshore platform
Publisher: Elsevier BV
Date: 03-2016
The importance of rheology characterization in predicting turbulent pipe flow of generalized Newtonian fluids
Publisher: Elsevier BV
Date: 06-2016
Solitary wave interaction with upright thin porous barriers
Publisher: Elsevier BV
Date: 2023
The effect of yield stress on pipe flow turbulence for generalised newtonian fluids
Publisher: Elsevier BV
Date: 11-2017
Creating analytically divergence-free velocity fields from grid-based data
Publisher: Elsevier BV
Date: 10-2016
Reynolds number effects in pipe flow turbulence of generalized Newtonian fluids
Publisher: American Physical Society (APS)
Date: 28-09-2018
Computed oscillations of a confined submerged liquid jet
Publisher: Elsevier BV
Date: 11-1998
Wave interaction with a tethered buoy: SPH simulation and experimental validation
Publisher: Elsevier BV
Date: 05-2018
Experimental Investigation on Solitary Wave Interaction With Vertical Porous Barriers
Publisher: ASME International
Date: 25-02-2020
DOI: 10.1115/1.4046194
Abstract: Tsunami waves pose a threat to the coastal zone, and numerous studies have been carried out in the past to understand them. Solitary waves have been extensively used in research because they approximate certain important characteristics of tsunami waves. The present study focusses on the interaction and run-up of solitary waves on coastal protection structures in the form of thin, rigid vertical porous barriers with special attention given to the degree of energy dissipation. To understand the physics of energy dissipation, solitary wave interaction with a porous barrier has been studied from the viewpoint of energy balance. Based on this, a relationship for the wave energy dissipation has been developed. The experimental data show that the plate porosity that gives the optimal energy dissipation lies within the 10–20% range. From the experiments, the phase shift that the solitary wave undergoes upon interaction with the porous barrier models has also been recorded. In addition, a formula is proposed for maximum wave run-up on the porous barrier, which should be useful in the planning, design, construction, and maintenance of coastal protection structures.
Aggregate densification in the thickening of flocculated suspensions in an un-networked bed
Publisher: Elsevier BV
Date: 2015
The effect of pressure solution in SPH simulations of sloshing flow
Publisher: ASMEDC
Date: 2011
Abstract: In modelling incompressible flows using the Smoothed Particle Hydrodynamics method (SPH), an equation of state with a large sound speed is typically used. This weakly compressible approach (WCSPH), results in a stiff set of equations with a noisy pressure field and stability issues at high Reynolds number. As a remedy, an incompressible SPH technique was introduced [1] (ISPH), which uses a pressure projection technique to model incompressibility. In this paper, the incompressible and weakly compressible forms of the SPH method are employed to study sloshing flow. Both methods are compared with experimental data. The results show the incompressible SPH method provides more accurate pressure fields and free-surface profiles when compared to experiment.
Characterisation of Oscillations in Multi-phase Unbaffled Mixing Vessels
Publisher: Elsevier BV
Date: 09-2023
A volume-tracking method for incompressible multifluid flows with large density variations
Publisher: Wiley
Date: 15-08-1998
DOI: 10.1002/(SICI)1097-0363(19980815)28:2<357::AID-FLD750>3.0.CO;2-D
Related Organisations
Related Funding Activities
Linkage Projects - Grant ID: LP0347947
Start Date: 02-2003
End Date: 06-2006
Amount: $314,599.00
Funder: Australian Research Council
View Funded ActivityDiscovery Projects - Grant ID: DP0773572
Start Date: 2007
End Date: 2014
Amount: $180,000.00
Funder: Australian Research Council
View Funded ActivityLinkage Projects - Grant ID: LP0989733
Start Date: 03-2009
End Date: 12-2012
Amount: $397,000.00
Funder: Australian Research Council
View Funded ActivityLinkage Projects - Grant ID: LP180100869
Start Date: 08-2020
End Date: 07-2024
Amount: $431,842.00
Funder: Australian Research Council
View Funded ActivityLinkage - CSIRO - Grant ID: LC0348317
Start Date: 10-2003
End Date: 10-2006
Amount: $193,035.00
Funder: Australian Research Council
View Funded ActivityIndustrial Transformation Research Hubs - Grant ID: IH140100035
Start Date: 12-2016
End Date: 12-2021
Amount: $5,000,000.00
Funder: Australian Research Council
View Funded ActivityLinkage Projects - Grant ID: LP0561978
Start Date: 07-2005
End Date: 12-2008
Amount: $635,000.00
Funder: Australian Research Council
View Funded ActivityIndustrial Transformation Research Hubs - Grant ID: IH230100010
Start Date: 01-2024
End Date: 01-2029
Amount: $5,000,000.00
Funder: Australian Research Council
View Funded ActivityDiscovery Projects - Grant ID: DP130103103
Start Date: 01-2013
End Date: 12-2017
Amount: $360,000.00
Funder: Australian Research Council
View Funded ActivityDiscovery Projects - Grant ID: DP220101660
Start Date: 08-2022
End Date: 08-2025
Amount: $287,000.00
Funder: Australian Research Council
View Funded Activity