Transport barriers in complex turbulent flows: formation, detection and characterization. Barriers to transport in complex fluid flows are ubiquitous in nature, yet mathematical and numerical approaches have so far been unable to solve this problem in the presence of turbulence. This project aims to undertake the first systematic laboratory study of transport barrier generation, control and interactions to reveal the role of turbulence in the stochastic transport in fluids. It will develop new m ....Transport barriers in complex turbulent flows: formation, detection and characterization. Barriers to transport in complex fluid flows are ubiquitous in nature, yet mathematical and numerical approaches have so far been unable to solve this problem in the presence of turbulence. This project aims to undertake the first systematic laboratory study of transport barrier generation, control and interactions to reveal the role of turbulence in the stochastic transport in fluids. It will develop new methods of transport barrier modelling which will equip specialists dealing with Lagrangian transport with new tools for the transport barrier modelling and characterisation.Read moreRead less
Studies of turbulence and coherent structures in quasi two-dimensional plasmas and fluids. One of the most celebrated but least understood complex systems in nature is turbulent flow. This cross-disciplinary project aims to contribute to basic scientific knowledge of a class of turbulent flows, known as quasi two-dimensional fluids, that typically exhibit self-organizing properties, stable sheared flow, and relatively weak dissipation. The significance lies in the proposed testing, by modelling ....Studies of turbulence and coherent structures in quasi two-dimensional plasmas and fluids. One of the most celebrated but least understood complex systems in nature is turbulent flow. This cross-disciplinary project aims to contribute to basic scientific knowledge of a class of turbulent flows, known as quasi two-dimensional fluids, that typically exhibit self-organizing properties, stable sheared flow, and relatively weak dissipation. The significance lies in the proposed testing, by modelling and simulation studies, of the well-grounded hypothesis that suppression of turbulence by sheared flow is a universal phenomenon in such fluids, and that it can be exploited to control transport of fluid constituents. Applications of this new knowledge will be developed.Read moreRead less
Low-order dynamical models for non-linear fluid behaviour in quasi two-dimensional plasmas. Two complex systems in which a magnetic field imposes two-dimensional fluid motions are turbulent fusion plasmas and magnetospheric plasmas. A distinctive property of 2D flows is the inverse energy cascade, whereby energy streaming into large-scale vortices, coherent structures, or sheared flows gives a remarkable propensity for self-organizing behaviour. This can be exploited to govern or guide our respo ....Low-order dynamical models for non-linear fluid behaviour in quasi two-dimensional plasmas. Two complex systems in which a magnetic field imposes two-dimensional fluid motions are turbulent fusion plasmas and magnetospheric plasmas. A distinctive property of 2D flows is the inverse energy cascade, whereby energy streaming into large-scale vortices, coherent structures, or sheared flows gives a remarkable propensity for self-organizing behaviour. This can be exploited to govern or guide our response to such systems. We propose to investigate the dynamics of momentum and energy exchange in these plasmas, using reduced dynamical models and bifurcation and stability mathematics. Expected outcomes are improved prediction of magnetospheric substorms and confinement of fusion plasmas.
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Structural transitions in turbulent fluids and plasma through self-organization. Studies into structural transitions in turbulent systems will greatly benefit Australia through its contributions to the science of complex systems, in the areas of self-organization and turbulence control. Applications range from understanding the formation of the Earth's atmospheric spectrum to generation of transport barriers in magnetically confined plasma, as well as development of novel methods of turbulence c ....Structural transitions in turbulent fluids and plasma through self-organization. Studies into structural transitions in turbulent systems will greatly benefit Australia through its contributions to the science of complex systems, in the areas of self-organization and turbulence control. Applications range from understanding the formation of the Earth's atmospheric spectrum to generation of transport barriers in magnetically confined plasma, as well as development of novel methods of turbulence control in engineering. Recent discoveries by the authors open a window of opportunity for a breakthrough in this fundamental field of modern science. The project is based on several national and international collaborations. Australian postgraduate and research training is an integral part of the project.Read moreRead less
A Laboratory Study of Ocean-Atmosphere Coupling in the Antarctic Circumpolar Wave. A laboratory model of the southern hemisphere mid-latitude ocean-atmosphere system will be used to investigate the dynamics of ocean-atmosphere coupling contributing to the Antarctic Circumpolar Wave (ACW). The ACW is a recently discovered multi-year climate oscillation which has considerable effect on Australian and New Zealand precipitation. This will be the first laboratory model to include global scale ocean-a ....A Laboratory Study of Ocean-Atmosphere Coupling in the Antarctic Circumpolar Wave. A laboratory model of the southern hemisphere mid-latitude ocean-atmosphere system will be used to investigate the dynamics of ocean-atmosphere coupling contributing to the Antarctic Circumpolar Wave (ACW). The ACW is a recently discovered multi-year climate oscillation which has considerable effect on Australian and New Zealand precipitation. This will be the first laboratory model to include global scale ocean-atmosphere processes, and will be used to test proposed mechanisms for the driving of the climate oscillation that is attributed to the ACW. The project will provide knowledge required for improved computational modelling and climate predictions.
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Nonlinear optics of soft matter. This project will develop new strategies for the use and control of soft-matter systems by exploiting nonlinear interactions with light, and therefore falls into the Designated Research Priority 3: Frontier Technologies for Building and Transforming Australian Industries - Breakthrough Science. With soft matter research being increasingly important for applications within industry and medicine, the emergence of new technology for control of nanoparticles could pr ....Nonlinear optics of soft matter. This project will develop new strategies for the use and control of soft-matter systems by exploiting nonlinear interactions with light, and therefore falls into the Designated Research Priority 3: Frontier Technologies for Building and Transforming Australian Industries - Breakthrough Science. With soft matter research being increasingly important for applications within industry and medicine, the emergence of new technology for control of nanoparticles could provide significant benefits for the scientific community as well as Australian companies.
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Relationship between subduction zone geometry, trench kinematics and great subduction earthquakes. The devastating Boxing Day 2004 earthquake near Sumatra and the four other largest earthquakes in recorded history all occurred along subduction zones. This research will compare the geodynamic setting of these subduction zones with those surrounding the Australian continent and assess whether the Australian subduction zones are capable of producing great earthquakes and tsunamis that might pose a ....Relationship between subduction zone geometry, trench kinematics and great subduction earthquakes. The devastating Boxing Day 2004 earthquake near Sumatra and the four other largest earthquakes in recorded history all occurred along subduction zones. This research will compare the geodynamic setting of these subduction zones with those surrounding the Australian continent and assess whether the Australian subduction zones are capable of producing great earthquakes and tsunamis that might pose a risk for the east and northwest coast of Australia. Also, Eastern Australia is a composite of fossil arcs rich in ore deposits and the Tasman Sea region is composed of basins that host hydrocarbons, all of which formed by subduction processes. The proposed research will thus improve the basis for mineral and hydrocarbon exploration.Read moreRead less
Rarefied hypervelocity separated flow in the transitional to continuum regimes. The transition regime for low-density flows is a no-man's-land between free-molecular and continuum flow, where the flow behaves differently to the assumptions typically used for modelling either flow type. Bird's direct Simulation Monte Carlo (DSMC) method is typically thought to be the best way of modelling these flows, but has not produced excellent agreement with previous experiments on low-density separated flow ....Rarefied hypervelocity separated flow in the transitional to continuum regimes. The transition regime for low-density flows is a no-man's-land between free-molecular and continuum flow, where the flow behaves differently to the assumptions typically used for modelling either flow type. Bird's direct Simulation Monte Carlo (DSMC) method is typically thought to be the best way of modelling these flows, but has not produced excellent agreement with previous experiments on low-density separated flows, due to computational limitations and lack of knowledge of the flow's internal energy. This proposal is a blind test of the best current DSMC codes against our experiments and a hypersonic continuum code, with the full internal energy state of the flow experimentally quantified for the first time.Read moreRead less
Nanorheology: Hydrodynamic Slip in Newtonian Fluids. Understanding fluid flow across a surface is essential to a great number of technologies. For over one hundred years it has been assumed that the layer of fluid adjacent to the solid moves with the solid, this is known as the no-slip boundary condition. Recently direct force balance measurements of aqueous Newtonian solutions have indicated the presence of boundary slip. Using a newly developed nanorheology technique we will systematically inv ....Nanorheology: Hydrodynamic Slip in Newtonian Fluids. Understanding fluid flow across a surface is essential to a great number of technologies. For over one hundred years it has been assumed that the layer of fluid adjacent to the solid moves with the solid, this is known as the no-slip boundary condition. Recently direct force balance measurements of aqueous Newtonian solutions have indicated the presence of boundary slip. Using a newly developed nanorheology technique we will systematically investigate the conditions that control boundary slip. This information will be used to quantify, model and control boundary slip, progressing the fields of microfluidics, particle deposition, and colloid stability.Read moreRead less
Nonhydrostatic waves and instabilities in rotating fluids. This project addresses a fundamental gap in our understanding of the ocean circulation. The benefits of the program will be to improve the way we model and predict the ocean circulation and the response of the ocean to climate change. The project will thereby assist National Research Priorities on global change and link with a major new ANU Marine Science Strategic Initiative.