Geometry of wall-turbulence and its potential to advance scalable models. This project aims to unravel the connections between the statistical geometry of wall-turbulence and the dynamical interactions of its instantaneous motions. Predicting the complex behaviour of turbulent fluid flow over surfaces in relative motion is central to atmospheric modelling for climate and agriculture, and reducing the environmental effect of fossil fuel usage. Wall-turbulence statistics organise according to a pr ....Geometry of wall-turbulence and its potential to advance scalable models. This project aims to unravel the connections between the statistical geometry of wall-turbulence and the dynamical interactions of its instantaneous motions. Predicting the complex behaviour of turbulent fluid flow over surfaces in relative motion is central to atmospheric modelling for climate and agriculture, and reducing the environmental effect of fossil fuel usage. Wall-turbulence statistics organise according to a predictable geometric structure, and the notorious complexity of turbulent wall-flow dynamics could be clarified through its inherent geometry. This project expects to construct a basis for predicting engineering and atmospheric wall-flows, which would enhance atmospheric flow prediction, reduce energy consumption and further environmental sustainability.Read moreRead less
Self-similar scale interactions in turbulent boundary layers. Predicting and controlling turbulent fluid flow next to a solid surface (the turbulent boundary layer) is of critical importance to ensuring a sustainable energy and environmental future. While recent research has yielded a clearer physical understanding of these flows, converting this understanding into tools useful to engineering practice remains a central obstacle. The proposed research directly addresses this fundamental challenge ....Self-similar scale interactions in turbulent boundary layers. Predicting and controlling turbulent fluid flow next to a solid surface (the turbulent boundary layer) is of critical importance to ensuring a sustainable energy and environmental future. While recent research has yielded a clearer physical understanding of these flows, converting this understanding into tools useful to engineering practice remains a central obstacle. The proposed research directly addresses this fundamental challenge by precisely connecting the eddy interactions of the turbulence to the mathematical equations that rigorously describe these flows. As such it holds breakthrough potential toward the development of turbulent boundary layer prediction and control schemes that do not rely on ad hoc models or assumptions.Read moreRead less
Simulating two-phase electrodynamic flows in droplet-based microfluidic circuit elements. The knowledge, data and analysis tools developed within this project will facilitate the economical production of electrodynamically controlled integrated droplet-based microfluidic devices for critical high-demand applications such as: genome sequencing; protein evolution, synthesis and crystallisation; micro-structured pharmaceuticals; disposable devices for biomedical analysis; portable point-of-entry (b ....Simulating two-phase electrodynamic flows in droplet-based microfluidic circuit elements. The knowledge, data and analysis tools developed within this project will facilitate the economical production of electrodynamically controlled integrated droplet-based microfluidic devices for critical high-demand applications such as: genome sequencing; protein evolution, synthesis and crystallisation; micro-structured pharmaceuticals; disposable devices for biomedical analysis; portable point-of-entry (biochem)security analysis devices. Hence this project is an investment in enabling technologies to benefit Australia's growing biotech, pharmaceutical and micro/nanotechnology sectors. Tangible community benefits (e.g., in improved diagnostic technologies, pharmaceuticals) will result.Read moreRead less
Gravity Current Driven Smoke Dispersion In a Stratified Ambient. Smoke from bushfires transported by gravity currents, and known to occur nationwide, caused the shutdown of businesses, education and events in Canberra in 2019. Recent scientific investigations have shown that the speed of propagation and concentration of smoke in these three-dimensional gravity currents have a long term ‘memory’ of their initial configuration. In this project, high-fidelity computational and experimental techniq ....Gravity Current Driven Smoke Dispersion In a Stratified Ambient. Smoke from bushfires transported by gravity currents, and known to occur nationwide, caused the shutdown of businesses, education and events in Canberra in 2019. Recent scientific investigations have shown that the speed of propagation and concentration of smoke in these three-dimensional gravity currents have a long term ‘memory’ of their initial configuration. In this project, high-fidelity computational and experimental techniques will be used to elucidate the fundamental mechanisms of gravity current entrainment and propagation. This knowledge will set a strong foundation to improve operational forecasts of smoke transport that will allow government agencies to better respond to the negative impact of these complicated flows.Read moreRead less
DROP DEFORMATION IN CONFINED MICROFLUIDIC GEOMETRIES. Increasingly, high technology applications in biotechnology and microtechnology industries need to process complex (non-Newtonian) fluids with dispersed particles/droplets in channels as small as several microns (microfluidics). A computational fluid dynamic model of non-Newtonian droplet deformation in microfluidic geometries will be developed, and validated using experimental measurements of the flow field in this project. The aim is to und ....DROP DEFORMATION IN CONFINED MICROFLUIDIC GEOMETRIES. Increasingly, high technology applications in biotechnology and microtechnology industries need to process complex (non-Newtonian) fluids with dispersed particles/droplets in channels as small as several microns (microfluidics). A computational fluid dynamic model of non-Newtonian droplet deformation in microfluidic geometries will be developed, and validated using experimental measurements of the flow field in this project. The aim is to understand and quantify factors influencing droplet deformation. Coupling non-Newtonian characteristics with microfluidic geometries will allow the continuous manufacture of micro-particles of specified size and shape for existing and new applications, and will provide guidance for further extending the process to nano-particle manufacture.Read moreRead less
Electro-viscous effects on pressure-driven liquid flow in microchannels. Australian biotechnology, information technology and food technology industries will benefit from the development of new tailored micro- and nano-fluidic devices for processing of non-Newtonian fluids. The efficiency of functional elements such as valves, pumps, mixers, reactors, heat exchangers can be optimised for specific fluids by understanding the coupling between the fluid properties, the device geometry, surface cha ....Electro-viscous effects on pressure-driven liquid flow in microchannels. Australian biotechnology, information technology and food technology industries will benefit from the development of new tailored micro- and nano-fluidic devices for processing of non-Newtonian fluids. The efficiency of functional elements such as valves, pumps, mixers, reactors, heat exchangers can be optimised for specific fluids by understanding the coupling between the fluid properties, the device geometry, surface charge, and the numerical predictions. This understanding will complement development in related projects on non-Newtonian drop and particle formation in microfluidic flows which envisage continuous particle manufacture for novel materials possessing programmable, enhanced functional properties.Read moreRead less
Application of exact coherent structures to transition and turbulence. This project aims to understand coherent structures and devise methods to prevent bypass transition to turbulence and reduce turbulent wall drag. Coherent structures in turbulence may be identified with nonlinear solutions of the exact equations of motion. Such "exact" coherent structures have their Reynolds number dependence described explicitly and apply for moderate to very large Reynolds numbers, well above the range of f ....Application of exact coherent structures to transition and turbulence. This project aims to understand coherent structures and devise methods to prevent bypass transition to turbulence and reduce turbulent wall drag. Coherent structures in turbulence may be identified with nonlinear solutions of the exact equations of motion. Such "exact" coherent structures have their Reynolds number dependence described explicitly and apply for moderate to very large Reynolds numbers, well above the range of full Navier–Stokes calculations. Understanding the fundamentals of turbulence is expected to lead to more efficient and cheaper air transportation, and better tools for climate prediction and short-term weather forecasting.Read moreRead less
A Novel Approach To Flow Control By Topography. The project will resolve important questions concerning the influence of boundary topography on transition to turbulence and on the exact coherent structures forming the backbone of turbulence.
The canonical topography known from previous work by one of the investigators is a wavy wall and, as well as resolving important issues in flow physics, the research is relevant to many flows of importance such roughness induced transition on aircraft wings, ....A Novel Approach To Flow Control By Topography. The project will resolve important questions concerning the influence of boundary topography on transition to turbulence and on the exact coherent structures forming the backbone of turbulence.
The canonical topography known from previous work by one of the investigators is a wavy wall and, as well as resolving important issues in flow physics, the research is relevant to many flows of importance such roughness induced transition on aircraft wings, flows in heat transfer/mixing devices, blood flow and the influence of topography on the atmospheric boundary layer.
Expected outcomes are an understanding of the interplay between transitional and turbulent flows with wall topography together with strategies to enhance mixing and drag reduction.Read moreRead less
Supersonic flow past micro-scale particles: Industrial applications. Droplet based materials processing has developed significantly over the last decade, with applications in a wide range of industries where high-strength, light-weight materials are critical. Our research will allow for continued progress of this method, by developing accurate models to predict the cooling rate throughout the process and hence the physical properties of the finished product. Development of this knowledge will al ....Supersonic flow past micro-scale particles: Industrial applications. Droplet based materials processing has developed significantly over the last decade, with applications in a wide range of industries where high-strength, light-weight materials are critical. Our research will allow for continued progress of this method, by developing accurate models to predict the cooling rate throughout the process and hence the physical properties of the finished product. Development of this knowledge will allow for higher precision products to be produced and allow for new techniques to be developed. This information will allow for material processing in Australia to be maintained at world class levels, and for Australian industry to continue to lead the way in the production of technologically advanced materials.Read moreRead less
The effect of turbulence scale and intensity on water flow measurement using ultrasonic techniques. Management of water resources and water distribution networks is important as Australia and the world face increasing water shortages. A significant aspect of water management is prevention of supply losses in urban and non-urban water distribution networks - a vital factor in improving water security of Australian cities and agricultural production regions. This research will develop ultrasonic f ....The effect of turbulence scale and intensity on water flow measurement using ultrasonic techniques. Management of water resources and water distribution networks is important as Australia and the world face increasing water shortages. A significant aspect of water management is prevention of supply losses in urban and non-urban water distribution networks - a vital factor in improving water security of Australian cities and agricultural production regions. This research will develop ultrasonic flow-velocity technology, which can be retrofitted to existing water distribution networks, providing distributed high precision water flow measurement systems that can prevent the loss each year of more than 155GL of water through leaks and burst in Australia's capital cities alone.Read moreRead less