Unravelling the scale interactions of wall turbulence: experiment, physical modelling, next-generation numerical simulation. Turbulent fluid flows near solid surfaces are present in many areas of everyday life: from the drag experienced on air, sea and road vehicles, to governing the mixing processes in combustion chambers, and in the transport of pollutants and particulates in our cities and towns. Unfortunately our understanding of these complex flows is limited, and hence so to is our ability ....Unravelling the scale interactions of wall turbulence: experiment, physical modelling, next-generation numerical simulation. Turbulent fluid flows near solid surfaces are present in many areas of everyday life: from the drag experienced on air, sea and road vehicles, to governing the mixing processes in combustion chambers, and in the transport of pollutants and particulates in our cities and towns. Unfortunately our understanding of these complex flows is limited, and hence so to is our ability to model or control them. This project addresses this problem with the goal of providing new physical insights and models that can be used for efficient and accurate numerical simulations. The simulations will not only compute the average statistics but also the time-varying properties, which are crucial in many engineering and environmental processes.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
A novel approach to controlling boundary-layer separation. This project will involve fundamental research into the control of the fluid dynamical phenomena of boundary-layer separation and transition to turbulence. The project will be built upon a firm foundation of mathematical modelling of the complex behaviour of fluid flows that are near the onset of flow separation or turbulence. The project will produce results that will permit the development of control strategies that can be implemented ....A novel approach to controlling boundary-layer separation. This project will involve fundamental research into the control of the fluid dynamical phenomena of boundary-layer separation and transition to turbulence. The project will be built upon a firm foundation of mathematical modelling of the complex behaviour of fluid flows that are near the onset of flow separation or turbulence. The project will produce results that will permit the development of control strategies that can be implemented in a wide variety of important technological applications, such as drag reduction in the aerospace and ship industries as well as the control of stall (or loss of lift) in modern aircraft.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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Robust fluid mixing through topological chaos. The Australian chemicals and plastics industry has an annual turnover of over $20 billion and employs over 77,000 people; fluid mixing is fundamental to this industry, yet the industry is recognised as underinvesting in research and development in this essential area. Furthermore, frontier technologies such as biotechnology and the next generation of smart materials also crucially rely on fluid mixing. This project aims to evaluate a new paradigm ( ....Robust fluid mixing through topological chaos. The Australian chemicals and plastics industry has an annual turnover of over $20 billion and employs over 77,000 people; fluid mixing is fundamental to this industry, yet the industry is recognised as underinvesting in research and development in this essential area. Furthermore, frontier technologies such as biotechnology and the next generation of smart materials also crucially rely on fluid mixing. This project aims to evaluate a new paradigm (topological chaos) for the design of mixers, to provide better and more robust mixers that work from microscopic to industrial scales.Read moreRead less
Systematically model the large-scale complexity of turbulent floods and thin film flows. This project continues development of new models, and computer
simulation, of turbulent flood, river and estuarine flow. The models
will be based systematically upon established turbulence models to
resolve accurately the complex physical processes. The development of
new and robust computer models for thin layers of coating fluid will
aid many industrial processes. We also aim to provide correct ini ....Systematically model the large-scale complexity of turbulent floods and thin film flows. This project continues development of new models, and computer
simulation, of turbulent flood, river and estuarine flow. The models
will be based systematically upon established turbulence models to
resolve accurately the complex physical processes. The development of
new and robust computer models for thin layers of coating fluid will
aid many industrial processes. We also aim to provide correct initial
conditions and boundary conditions for simpler cases of the above
flows. The approach leads to a greater understanding of the range of
applicability of the models through better estimating the errors in the
modelling process. The project develops a fundamental enabling
methodology for engineering and the sciences.
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The propagation of gravity currents over complex terrain. Dust storms, volcanic eruptions, rivers rushing sediment into lakes and seas, and spillages of toxic liquids and gases, are all examples of environmental problems that can occur, and when they do, they threaten both wild life and human communities. This project involves research that will provide quantitative understanding of key processes in these problems from which reliable software will be built to predict their consequences. The soft ....The propagation of gravity currents over complex terrain. Dust storms, volcanic eruptions, rivers rushing sediment into lakes and seas, and spillages of toxic liquids and gases, are all examples of environmental problems that can occur, and when they do, they threaten both wild life and human communities. This project involves research that will provide quantitative understanding of key processes in these problems from which reliable software will be built to predict their consequences. The software will produce an animation of dust containing fluids moving over a landscape of arbitrary complexity.Read moreRead less
A theoretical investigation into the effect of nonlinear wave interactions in promoting transition-to-turbulence. The problem of transition-to-turbulence remains one of the fundamental unanswered questions in fluid dynamics. An understanding of the processes leading to transition is necessary if the active control of turbulence is to be achieved. This project will focus attention on a new class of waves, which have only recently been described the CI, in order to determine how they are triggered ....A theoretical investigation into the effect of nonlinear wave interactions in promoting transition-to-turbulence. The problem of transition-to-turbulence remains one of the fundamental unanswered questions in fluid dynamics. An understanding of the processes leading to transition is necessary if the active control of turbulence is to be achieved. This project will focus attention on a new class of waves, which have only recently been described the CI, in order to determine how they are triggered and how they may serve to actively promote the early development of turbulence in a broad class of fluid flows.Read moreRead less
The next generation of stellar models: incorporating the results of multidimensional hydrodynamics. This project involves the use of computer codes designed for massively-parallel computing, thousands of computers tied together into one cluster, to tackle difficult hydrodynamic problems that occur in stars. We will train PhD students in this area of cutting-edge computation, with applications in areas such as meteorology, aero-space and defence. The skills gained by the participants in this proj ....The next generation of stellar models: incorporating the results of multidimensional hydrodynamics. This project involves the use of computer codes designed for massively-parallel computing, thousands of computers tied together into one cluster, to tackle difficult hydrodynamic problems that occur in stars. We will train PhD students in this area of cutting-edge computation, with applications in areas such as meteorology, aero-space and defence. The skills gained by the participants in this project will be useful over a wide range of areas in the modern economy of the nation.Read moreRead less
The effect of diffusive mass transfer on interfacial fluid instabilities. A wide variety of industrial and physiological fluid flows fall into the general class of two-layer fluids wherein a fluid of one density/viscosity flows over another of a different density/viscosity. Such flows can ultimately become turbulent (that is, chaotic) through the growth of small background disturbances. An understanding of this process is important in controlling fluid dynamical mixing. This project will conside ....The effect of diffusive mass transfer on interfacial fluid instabilities. A wide variety of industrial and physiological fluid flows fall into the general class of two-layer fluids wherein a fluid of one density/viscosity flows over another of a different density/viscosity. Such flows can ultimately become turbulent (that is, chaotic) through the growth of small background disturbances. An understanding of this process is important in controlling fluid dynamical mixing. This project will consider two layer flows in the case when diffusive mass transfer acts at the fluid interface with the aim of determining how diffusion affects the process of transition-to-turbulence.Read moreRead less