Fluctuations in the properties of nonequilibrium fluids and the influence of thermostatting mechanisms. The behaviour of nonequilibrium fluids will be studied by combining ideas from liquid state theory, statistical mechanics and dynamical systems theory. This work will result in development and testing of mathematical expressions (Fluctuation Theorems) that are consistent with the Second Law of Thermodynamics, which determines the direction of any change in any macroscopic system, but are also ....Fluctuations in the properties of nonequilibrium fluids and the influence of thermostatting mechanisms. The behaviour of nonequilibrium fluids will be studied by combining ideas from liquid state theory, statistical mechanics and dynamical systems theory. This work will result in development and testing of mathematical expressions (Fluctuation Theorems) that are consistent with the Second Law of Thermodynamics, which determines the direction of any change in any macroscopic system, but are also applicable to microscopic systems. The expressions will determine the probability that finite sized systems will violate the Second Law for small periods of time and will therefore contribute to development of a fundamental understanding of microscopic systems and the development of nanotechnology.
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Fluid properties and chaotic dynamics in equilibrium and nonequilibrium states. Over the last decade a revolution has been taking place in nonequilibrium statistical mechanics [Physics Today, Sept, 2002]. This revolution is characterized by adapting the mathematical theory of chaos to nonequilibrium statistical mechanics. Fundamental new theorems and algorithms for computing transport coefficients have been derived. The CIs have played a key role in this revolution. We seek to broaden these dev ....Fluid properties and chaotic dynamics in equilibrium and nonequilibrium states. Over the last decade a revolution has been taking place in nonequilibrium statistical mechanics [Physics Today, Sept, 2002]. This revolution is characterized by adapting the mathematical theory of chaos to nonequilibrium statistical mechanics. Fundamental new theorems and algorithms for computing transport coefficients have been derived. The CIs have played a key role in this revolution. We seek to broaden these developments by: generalizing a theorem which relates transport coefficients to chaoticity; detailed studies of the influence of thermostatting mechanisms on nonequilibrium chaoticity and fluctuations, and by understanding the range of applicability of a nonequilibrium fluctuation theorem for non-isoenergetic systems.Read moreRead less
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
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
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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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 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
Optimal nose shaping for delayed boundary-layer separation and transition in axisymmetric flow. The aim of this project is to design a smooth nose for a body of revolution placed in axisymmetric flow of a viscous fluid at high Reynolds number, such that the boundary layer on the body remains unseparated. This can always be done with a sufficiently long nose, but our objective here is to minimise the necessary nose length. Outer potential flows will be provided via ring sources. The potential flo ....Optimal nose shaping for delayed boundary-layer separation and transition in axisymmetric flow. The aim of this project is to design a smooth nose for a body of revolution placed in axisymmetric flow of a viscous fluid at high Reynolds number, such that the boundary layer on the body remains unseparated. This can always be done with a sufficiently long nose, but our objective here is to minimise the necessary nose length. Outer potential flows will be provided via ring sources. The potential flows will be used to determine inner boundary layer solutions. Transition-to-turbulence will be considered by undertaking 2D and 3D stability computations.Read moreRead less
Topological Optimisation of Fluid Mixing. The proposed research is aimed at improving the efficiency of fluid mixers,
which in the long term has potential to reduce vastly the economic and
environmental costs associated with large-scale mixing processes in Australian
chemical industries. The research will not only impact on practical mixer
design, but will also develop important results in the application of topology
to the the field of chaotic dynamical systems. This project will also prov ....Topological Optimisation of Fluid Mixing. The proposed research is aimed at improving the efficiency of fluid mixers,
which in the long term has potential to reduce vastly the economic and
environmental costs associated with large-scale mixing processes in Australian
chemical industries. The research will not only impact on practical mixer
design, but will also develop important results in the application of topology
to the the field of chaotic dynamical systems. This project will also provide a
graduate student and post-doctoral researcher with training to pursue a career
in fluid dynamics or general applied mathematics research.
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