Effective and accurate model dynamics, deterministic and stochastic, across multiple space and time scales. A persistent feature of complex systems in engineering and science is the emergence of macroscopic, coarse grained, coherent behaviour from the interactions of microscopic agents (molecules, cells, grains) and with their environment. In current modeling, ranging from ecology to materials science, the underlying microscopic mechanisms are often known, but the closures to translate microscal ....Effective and accurate model dynamics, deterministic and stochastic, across multiple space and time scales. A persistent feature of complex systems in engineering and science is the emergence of macroscopic, coarse grained, coherent behaviour from the interactions of microscopic agents (molecules, cells, grains) and with their environment. In current modeling, ranging from ecology to materials science, the underlying microscopic mechanisms are often known, but the closures to translate microscale knowledge to a system level macroscopic description are rarely available in closed form. Our novel methodology will explore this stumbling block, and promises to radically change the modeling, exploration and understanding of multiscale complex system behaviour.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
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
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
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
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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Modelling of multiscale systems in engineering and science supports large-scale equation-free simulations and analysis. A persistent feature of complex systems in engineering and science is the emergence of macroscopic, coarse grained, coherent behaviour from the interactions of microscopic agents (molecules, cells) and with their environment. In current modeling, ranging from ecology to materials science, the underlying microscopic mechanisms are known, but the closures to translate microscale ....Modelling of multiscale systems in engineering and science supports large-scale equation-free simulations and analysis. A persistent feature of complex systems in engineering and science is the emergence of macroscopic, coarse grained, coherent behaviour from the interactions of microscopic agents (molecules, cells) and with their environment. In current modeling, ranging from ecology to materials science, the underlying microscopic mechanisms are known, but the closures to translate microscale knowledge to a system level macroscopic description are rarely available in closed form. Our novel, equation free, computational methodologies will circumvent this stumbling block, and promises to radically change the modeling, exploration and understanding of complex system behavior. We continue to develop this powerful computational methodology. 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
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