Turbulent mixing of a passive scalar. Turbulence is the usual state of fluid motion. This proposal will increase Australia's expertise in fundamental turbulence research, especially in the area of turbulent mixing, which is of major importance in many natural and engineering problems involving combustion, chemical reactions and pollution. A better knowledge of mixing at small scales will lead to more efficient combustion, savings in energy expenditure as well as a reduction in pollutant emiss ....Turbulent mixing of a passive scalar. Turbulence is the usual state of fluid motion. This proposal will increase Australia's expertise in fundamental turbulence research, especially in the area of turbulent mixing, which is of major importance in many natural and engineering problems involving combustion, chemical reactions and pollution. A better knowledge of mixing at small scales will lead to more efficient combustion, savings in energy expenditure as well as a reduction in pollutant emissions. Read moreRead less
Entrainment and Mixing in Turbulent Negatively Buoyant Jets and Fountains. The project intends to develop tools to accurate predict fountain flows. Volcanic eruptions, building ventilation and brine discharge from desalination plants are all examples of turbulent fountains and negatively buoyant jets. The project aims to conduct an investigation into the turbulent structure of fountains and negatively buoyant jets using numerical simulation and laboratory experiments, and to assess the accuracy ....Entrainment and Mixing in Turbulent Negatively Buoyant Jets and Fountains. The project intends to develop tools to accurate predict fountain flows. Volcanic eruptions, building ventilation and brine discharge from desalination plants are all examples of turbulent fountains and negatively buoyant jets. The project aims to conduct an investigation into the turbulent structure of fountains and negatively buoyant jets using numerical simulation and laboratory experiments, and to assess the accuracy of the commonly used integral models and test the effect of the use of more accurate entrainment relations. This may have a range of applications – enabling better prediction of environmental impacts, reduction of the adverse effects of the discharge of pollutants, and reduction in energy consumption in building ventilation and other industrial applications.Read moreRead less
Fluid-structure-acoustics interactions of bio-inspired flapping wings. This project aims to produce a deeper understanding of the role of wingtip feathers in the remarkable abilities of birds to fly in unsteady and unpredictable aerodynamic environments, and in some cases to do so almost silently. This is achieved by developing novel numerical methods integrating fluid, structure and acoustics interactions for large deformations and complex geometries. The numerical results are validated and com ....Fluid-structure-acoustics interactions of bio-inspired flapping wings. This project aims to produce a deeper understanding of the role of wingtip feathers in the remarkable abilities of birds to fly in unsteady and unpredictable aerodynamic environments, and in some cases to do so almost silently. This is achieved by developing novel numerical methods integrating fluid, structure and acoustics interactions for large deformations and complex geometries. The numerical results are validated and complemented by using flow, structure and acoustics experiments on dynamically scaled models. The insight gained provides design guidance for more efficient, robust and stable flight of bio-inspired micro air vehicles, and in reducing the noise impact of wind turbines by innovative blade leading edge and tip shaping.Read moreRead less
Thermal stratification, overturning and mixing in riverine environments. Thermal stratification is common in Australia's rivers due to our hot, drought-prone climate and high human demands relative to available supply, which has led to a significant reduction in flows relative to natural levels. Thermal stratification inhibits mixing, creating stagnant conditions characterised by low oxygen levels and increased concentrations of contaminants, leading to algal blooms, fish kills and systemic dama ....Thermal stratification, overturning and mixing in riverine environments. Thermal stratification is common in Australia's rivers due to our hot, drought-prone climate and high human demands relative to available supply, which has led to a significant reduction in flows relative to natural levels. Thermal stratification inhibits mixing, creating stagnant conditions characterised by low oxygen levels and increased concentrations of contaminants, leading to algal blooms, fish kills and systemic damage to ecosystems. The aim of this project is to develop predictive models for the effects of physical processes such as night-time cooling, wind, turbulence and currents on riverine thermal stratification. This is expected to enable a more accurate determination of the flow rates required to maintain the health of our river systems.Read moreRead less
Predictive capability for particle capture in aquatic ecosystems. This project investigates the fundamental fluid mechanics of particle capture, whereby suspended particles contact and adhere to a solid structure. This process is examined in productive and biodiverse ecosystems (such as coral reefs and seagrass meadows) whose health, productivity and propagation are directly controlled by particle capture. Existing formulations for particle capture are valid only under highly idealised condition ....Predictive capability for particle capture in aquatic ecosystems. This project investigates the fundamental fluid mechanics of particle capture, whereby suspended particles contact and adhere to a solid structure. This process is examined in productive and biodiverse ecosystems (such as coral reefs and seagrass meadows) whose health, productivity and propagation are directly controlled by particle capture. Existing formulations for particle capture are valid only under highly idealised conditions that are grossly unrepresentative of the complexity of ecosystem flows. The goal of this project is to use a coupled computational-experimental campaign to develop predictive capability for particle capture in ecosystems, where the flow can be turbulent and/or wave-dominated and the biological structures complex.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
Silencing the screech tone - noise suppression in supersonic jets. The focus of this research is to further develop understanding of the fundamental mechanics of the aeroacoustic phenomenon known as screech. From this deeper understanding a range of tailored control mechanisms are expected to be developed to reduce or eliminate the effects of screech in the engines of high-speed aircraft. The research builds on existing expertise and established experimental facilities. As well as an improved un ....Silencing the screech tone - noise suppression in supersonic jets. The focus of this research is to further develop understanding of the fundamental mechanics of the aeroacoustic phenomenon known as screech. From this deeper understanding a range of tailored control mechanisms are expected to be developed to reduce or eliminate the effects of screech in the engines of high-speed aircraft. The research builds on existing expertise and established experimental facilities. As well as an improved understanding of fundamental mechanism, the expected outcomes of the research are more efficient active and passive flow control devices for the reduction of supersonic jet noise.Read moreRead less
Stability, transition and heat transfer in thermally coupled natural convection boundary layers. Thermally coupled natural convection systems occur when a conducting vertical wall separates two fluids at different temperatures. Such configurations occur, for example, at a window separating the interior of a room from the outside or when a container of fluid is placed in a refrigerator. Improved building heating/cooling and ventilation, and more efficient refrigeration systems, require a thoroug ....Stability, transition and heat transfer in thermally coupled natural convection boundary layers. Thermally coupled natural convection systems occur when a conducting vertical wall separates two fluids at different temperatures. Such configurations occur, for example, at a window separating the interior of a room from the outside or when a container of fluid is placed in a refrigerator. Improved building heating/cooling and ventilation, and more efficient refrigeration systems, require a thorough understanding and predictive capability for these flows. This project will develop experimental, numerical and analytic tools to predict these flows and provide simple scaling relations for bulk flow parameters such as the heat transfer across the wall, which will be of immediate use in the associated industries.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
Practical wall-turbulence drag reduction through adaptive control. Long term increases in the price of aviation fuel disproportionately impacts on Australian carriers, given our geographic isolation and the resulting greater percentage of long-haul flights. The resulting higher fares will also have a direct impact on international tourism to Australia. One way to reduce the impact of rising fuel cost, and to reduce CO2 and other emissions at the same time, is to decrease drag on aircraft. This ....Practical wall-turbulence drag reduction through adaptive control. Long term increases in the price of aviation fuel disproportionately impacts on Australian carriers, given our geographic isolation and the resulting greater percentage of long-haul flights. The resulting higher fares will also have a direct impact on international tourism to Australia. One way to reduce the impact of rising fuel cost, and to reduce CO2 and other emissions at the same time, is to decrease drag on aircraft. This project will develop understanding in wall turbulence and adaptive control, and use this to experimentally demonstrate active reductions in skin friction drag. The results are equally applicable to a range of other applications including sea transport, pipe flows and combustor designs.Read moreRead less