GEOMETRIC NUMERICAL INTEGRATION. Many scientific phenomena in physics, astronomy, and chemistry, are modelled by ordinary differential equations (ODEs). Often these equations have no solution in closed form, and one relies on numerical integration. Traditionally this is done using Runge-Kutta methods or linear multistep methods. In the last decade, however, we (and others) have discovered novel classes of so-called "geometric" numerical integration methods that preserve qualititative featur ....GEOMETRIC NUMERICAL INTEGRATION. Many scientific phenomena in physics, astronomy, and chemistry, are modelled by ordinary differential equations (ODEs). Often these equations have no solution in closed form, and one relies on numerical integration. Traditionally this is done using Runge-Kutta methods or linear multistep methods. In the last decade, however, we (and others) have discovered novel classes of so-called "geometric" numerical integration methods that preserve qualititative features of certain ODE's exactly (in contrast to traditional methods), leading to crucial stability improvements. Extending concepts from dynamical systems theory and traditional numerical ODEs, this project will improve, extend and systematize this new field of geometric integration.Read moreRead less
Multi-Group Stochastic Modelling of Population Balance for Gas-Liquid Flows. Multiphase flow systems are encountered in many process industries such as chemical, petroleum, mining, nuclear, energy, food and pharmaceutical, which are fundamental to the Australian economy. Commercially available computer codes for simulating such systems are currently widely used in many Australian industrial sectors. This research project will address the prevalent deficiency in many of these computer codes and ....Multi-Group Stochastic Modelling of Population Balance for Gas-Liquid Flows. Multiphase flow systems are encountered in many process industries such as chemical, petroleum, mining, nuclear, energy, food and pharmaceutical, which are fundamental to the Australian economy. Commercially available computer codes for simulating such systems are currently widely used in many Australian industrial sectors. This research project will address the prevalent deficiency in many of these computer codes and develop new models capable of predicting a wide range of industrial bubbly flow problems. The resultant improved computer codes will provide industries with significant benefits and, in particular, reduce times and costs in their design and production. Read moreRead less
THE DEVELOPMENT OF MECHANISTIC MODELS FOR BUBBLY FLOWS WITH HEAT AND MASS TRANSFER. Commercially available CFD computer codes are currently widely used in many Australian industrial sectors. It is clearly recognised that the state-of-the-art models for dealing with complex bubbly flows with/without heat and mass transfer in these computer codes require further developments and improvements. This research project will address the prevalent deficiency in many of these computer codes. It is antici ....THE DEVELOPMENT OF MECHANISTIC MODELS FOR BUBBLY FLOWS WITH HEAT AND MASS TRANSFER. Commercially available CFD computer codes are currently widely used in many Australian industrial sectors. It is clearly recognised that the state-of-the-art models for dealing with complex bubbly flows with/without heat and mass transfer in these computer codes require further developments and improvements. This research project will address the prevalent deficiency in many of these computer codes. It is anticipated that through this major development of new models capable of predicting a wide range of industrial bubbly flow problems and implementation thereafter in these computer codes, industries will experience significant benefits especially reduce time and costs in their design and production.Read moreRead less
Experimental and Numerical Modelling of Gas-Liquid Flows. Multiphase flow systems are encountered in many process industries such as chemical, petroleum, mining, energy, food and pharmaceutical, which are fundamental to the Australian economy. Commercially available computer codes for simulating such systems are currently widely used in many Australian industrial sectors. This research project will address the prevalent deficiency in many of these computer codes and develop new models capable of ....Experimental and Numerical Modelling of Gas-Liquid Flows. Multiphase flow systems are encountered in many process industries such as chemical, petroleum, mining, energy, food and pharmaceutical, which are fundamental to the Australian economy. Commercially available computer codes for simulating such systems are currently widely used in many Australian industrial sectors. This research project will address the prevalent deficiency in many of these computer codes and develop new models capable of predicting a wide range of industrial bubbly flow problems. The resultant improved computer codes will provide industries with significant benefits - especially reduced times and costs in their design and production.Read moreRead less
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
Existence and Stability of a Model for Three-Dimensional Toroidal Plasma Equilibria. There is great physical interest in modelling strongly non-axisymmetric toroidal plasmas, but fundamental existence problems have made rigorous numerical analysis so far impossible. We seek to overcome this by investigating a class of idealized, but physically motivated, magnetohydrodynamic equilibria with stepped pressure profiles for which existence in the neighbourhood of axisymmetry has been proven. We will ....Existence and Stability of a Model for Three-Dimensional Toroidal Plasma Equilibria. There is great physical interest in modelling strongly non-axisymmetric toroidal plasmas, but fundamental existence problems have made rigorous numerical analysis so far impossible. We seek to overcome this by investigating a class of idealized, but physically motivated, magnetohydrodynamic equilibria with stepped pressure profiles for which existence in the neighbourhood of axisymmetry has been proven. We will (i) develop numerical techniques to extend these piece-wise Beltrami states far away from axisymmetry (ii) develop practical tests to determine when existence breaks down (iii) analyze the frequency spectrum of small oscillations about such equilibria (iv) extend the model to two-fluid MHD.Read moreRead less
The next generation of stellar models: incorporating the results of multidimensional hydrodynamics. This project involves the use of computer codes designed for massively-parallel computing, thousands of computers tied together into one cluster, to tackle difficult hydrodynamic problems that occur in stars. We will train PhD students in this area of cutting-edge computation, with applications in areas such as meteorology, aero-space and defence. The skills gained by the participants in this proj ....The next generation of stellar models: incorporating the results of multidimensional hydrodynamics. This project involves the use of computer codes designed for massively-parallel computing, thousands of computers tied together into one cluster, to tackle difficult hydrodynamic problems that occur in stars. We will train PhD students in this area of cutting-edge computation, with applications in areas such as meteorology, aero-space and defence. The skills gained by the participants in this project will be useful over a wide range of areas in the modern economy of the nation.Read moreRead less
Modelling soft filled viscoelastic solids. Wheat flour doughs are made in vast quantities daily, and improvements in processing, especially in sheeting (rolling) and extrusion are needed. To enable this we will create a novel mathematical description of the material which will be useful for predicting the shapes of processed products. Wheat breeding cycles can be shortened by using the model rheological parameters, since baking quality is closely linked to dough rheology. A number of Australian ....Modelling soft filled viscoelastic solids. Wheat flour doughs are made in vast quantities daily, and improvements in processing, especially in sheeting (rolling) and extrusion are needed. To enable this we will create a novel mathematical description of the material which will be useful for predicting the shapes of processed products. Wheat breeding cycles can be shortened by using the model rheological parameters, since baking quality is closely linked to dough rheology. A number of Australian wheats will be considered and their rheologies will be compared.Read moreRead less
Investigation of 1/f noise mechanisms in HgCdTe heterostructure IR photodiodes. Since the performance of any photon detector is defined by its signal to noise ratio, the reduction of noise generating mechanisms is equally important to improvement of the signal. In this project we propose to carry out, for the first time, a comprehensive analysis of noise generating mechanisms in HgCdTe detectors using recently developed, two-dimensional analysis procedure. The main objective of this project is t ....Investigation of 1/f noise mechanisms in HgCdTe heterostructure IR photodiodes. Since the performance of any photon detector is defined by its signal to noise ratio, the reduction of noise generating mechanisms is equally important to improvement of the signal. In this project we propose to carry out, for the first time, a comprehensive analysis of noise generating mechanisms in HgCdTe detectors using recently developed, two-dimensional analysis procedure. The main objective of this project is to prove that 1/f noise in HgCdTe photodetectors is caused by dark current fluctuations in the high electric field regions of the detector structure. The primary outcome of this work will be the first comprehensive two-dimensional device model that can predict 1/f noise in a semiconductor device.Read moreRead less
Black Hole Accretion: The Effects of Magnetic Fields and Radiation. This project represents a significant contribution by Australian researchers to one of Science's Big Questions: How do Black Holes channel gravitational energy into radiation at many different energies and into high speed outflows. It offers Australian Astronomy an opportunity to expand its endeavours into the rapidly growing and high profile areas of high-energy and computational astrophysics, injecting new expertise into the i ....Black Hole Accretion: The Effects of Magnetic Fields and Radiation. This project represents a significant contribution by Australian researchers to one of Science's Big Questions: How do Black Holes channel gravitational energy into radiation at many different energies and into high speed outflows. It offers Australian Astronomy an opportunity to expand its endeavours into the rapidly growing and high profile areas of high-energy and computational astrophysics, injecting new expertise into the interpretation of multi-wavelength data on accreting black holes. We will train a new cohort of internationally competitive students and early career researchers, equipping them with the advanced computational and modelling skills that are in increasingly higher demand in many technology-based industries.Read moreRead less