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
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
Enhancement of Heat Transfer by Stimulated Transition to Turbulence in Natural Convection Boundary Layers on Heated Walls. The aim of this project is to increase the heat transfer from heated vertical surfaces to an ambient fluid by stimulating an early transition to turbulence. Such passive heat transfer occurs in heat transfer devices, natural ventilation systems and in many environmental settings. Enhanced heat transfer will greatly improve the performance of these systems. The project will ....Enhancement of Heat Transfer by Stimulated Transition to Turbulence in Natural Convection Boundary Layers on Heated Walls. The aim of this project is to increase the heat transfer from heated vertical surfaces to an ambient fluid by stimulating an early transition to turbulence. Such passive heat transfer occurs in heat transfer devices, natural ventilation systems and in many environmental settings. Enhanced heat transfer will greatly improve the performance of these systems. The project will provide the length scales, frequency and amplification rate for the occurence of the secondary spanwise mode that is the primary mechanism for turbulent transition. This will provide guidance for the development of appropriate roughness elements and heating length and time scales.Read moreRead less
Interstellar Gas Dynamics. The conversion of interstellar gas into stars is a key process in the life-history of galaxies and the formation of planetary systems. Star formation takes place within a heterogeneous, dynamic cloud, and entails a million-fold contraction controlled by a complex interplay between gravity, magnetic forces, ionisation balance, chemical reactions and particles of interstellar dust. Previous modelling has adopted inappropriate approximations for the evolution of the mag ....Interstellar Gas Dynamics. The conversion of interstellar gas into stars is a key process in the life-history of galaxies and the formation of planetary systems. Star formation takes place within a heterogeneous, dynamic cloud, and entails a million-fold contraction controlled by a complex interplay between gravity, magnetic forces, ionisation balance, chemical reactions and particles of interstellar dust. Previous modelling has adopted inappropriate approximations for the evolution of the magnetic field. This research will bring a rigorous treatment of magnetic diffusion to bear on the theory of cloud evolution, shock waves, star formation and protoplanetary discs.
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Investigation and optimisation of displacement ventilation and cooling systems. An accurate optimisation design tool for cooling and ventilation will be of considerable benefit to the Australian building/construction industry, and will lead to a reduction in energy consumption, thereby reducing both consumer costs and Australia's total greenhouse gas output, as well as providing Australian industry with a competitive advantage. Turbulence modelling for stratified fluids is one of the grand chall ....Investigation and optimisation of displacement ventilation and cooling systems. An accurate optimisation design tool for cooling and ventilation will be of considerable benefit to the Australian building/construction industry, and will lead to a reduction in energy consumption, thereby reducing both consumer costs and Australia's total greenhouse gas output, as well as providing Australian industry with a competitive advantage. Turbulence modelling for stratified fluids is one of the grand challenge areas of science, and graduate students and postdoctoral researchers trained in this area will be well placed to make a significant contribution to the new technologies needed to address the major environmental problems currently being faced.Read moreRead less
Turbulent fountains in stratified fluids with opposing buoyancy flux. Improved design tools will be developed for use in industries which must deal with turbulent fountains in stratified fluids. These tools will assist in the design of more efficient apparatus, reducing energy consumption and thereby reducing both consumer costs and Australia's total greenhouse gas output, as well as providing Australian industry with a competitive advantage. Turbulence modelling for stratified fluids is one of ....Turbulent fountains in stratified fluids with opposing buoyancy flux. Improved design tools will be developed for use in industries which must deal with turbulent fountains in stratified fluids. These tools will assist in the design of more efficient apparatus, reducing energy consumption and thereby reducing both consumer costs and Australia's total greenhouse gas output, as well as providing Australian industry with a competitive advantage. Turbulence modelling for stratified fluids is one of the grand challenge areas of science, and graduate students and postdoctoral researchers trained in this will provide continuing service to Australia in many areas of advanced engineering and science. Read moreRead less
An Investigation Into Fountains Interacting With Both Free Surface and Solid Boundaries. This project will produce an improved understanding of the behavior of fountains interacting with both free surface and solid boundaries. Such flows occur in many environmental and industrial processes and, in particular, the interaction of fountain with boundaries will have a significant influence on the overall performance of the processes. This investigation will combine experiments, numerical simulations ....An Investigation Into Fountains Interacting With Both Free Surface and Solid Boundaries. This project will produce an improved understanding of the behavior of fountains interacting with both free surface and solid boundaries. Such flows occur in many environmental and industrial processes and, in particular, the interaction of fountain with boundaries will have a significant influence on the overall performance of the processes. This investigation will combine experiments, numerical simulations and scaling analysis to provide new insight into the physics governing the behavior of these impinging fountains. Turbulence models will be developed and validated and scaling formulae will be obtained providing relationships for the basic flow properties in terms of the control parameters.Read moreRead less
Enhancing natural convection heat transfer using a single horizontal non-metallic fin. This project will develop the basis for a simple design to improve the energy efficiency of natural convection heat exchangers. Heat exchangers are widely adopted in many electronic devices and industrial processes as they require no external power input, additional space, and are quiet, reliable and economical. The research will exploit the interaction between two flows to trigger turbulence, and will result ....Enhancing natural convection heat transfer using a single horizontal non-metallic fin. This project will develop the basis for a simple design to improve the energy efficiency of natural convection heat exchangers. Heat exchangers are widely adopted in many electronic devices and industrial processes as they require no external power input, additional space, and are quiet, reliable and economical. The research will exploit the interaction between two flows to trigger turbulence, and will result in an increase of the overall capacity and performance of engineering systems. This will contribute significantly to reductions in power consumption and improvements in productivity and work environment, leading ultimately to reductions in greenhouse gas emissions and to economic benefits.Read moreRead less
Investigation of a Novel Fan. Fans are very widely used for cooling and heating, thrust and mass transport and are one of the most common fluid mechanical devices. An optimal fan design will maximise flow velocity and pressure rise for minimum energy requirements and noise production. De Rolfe has recently developed a new fan that shows considerable promise in comparison to conventional designs on single point tests.
In this project experimental and computional fluid dynamics investigations o ....Investigation of a Novel Fan. Fans are very widely used for cooling and heating, thrust and mass transport and are one of the most common fluid mechanical devices. An optimal fan design will maximise flow velocity and pressure rise for minimum energy requirements and noise production. De Rolfe has recently developed a new fan that shows considerable promise in comparison to conventional designs on single point tests.
In this project experimental and computional fluid dynamics investigations of the new fan will be carried out to determine the basic fluid mechanics and to obtain performance curves. Scaling laws will be obtained and, if possible, the fan will be further optimised.Read moreRead less
Nanorheology: Hydrodynamic Slip in Newtonian Fluids. Understanding fluid flow across a surface is essential to a great number of technologies. For over one hundred years it has been assumed that the layer of fluid adjacent to the solid moves with the solid, this is known as the no-slip boundary condition. Recently direct force balance measurements of aqueous Newtonian solutions have indicated the presence of boundary slip. Using a newly developed nanorheology technique we will systematically inv ....Nanorheology: Hydrodynamic Slip in Newtonian Fluids. Understanding fluid flow across a surface is essential to a great number of technologies. For over one hundred years it has been assumed that the layer of fluid adjacent to the solid moves with the solid, this is known as the no-slip boundary condition. Recently direct force balance measurements of aqueous Newtonian solutions have indicated the presence of boundary slip. Using a newly developed nanorheology technique we will systematically investigate the conditions that control boundary slip. This information will be used to quantify, model and control boundary slip, progressing the fields of microfluidics, particle deposition, and colloid stability.Read moreRead less