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
Elucidating the inertial force mechanisms of turbulence. The turbulent flow of fluids (for example, air, water) near a solid surface is of enormous technological importance. The proposed research will advance engineering prediction and control capabilities by revealing how the unsteady eddying motions produce the apparent inertial force that distinguishes turbulent flows from their laminar counterparts.
Surface roughness and its effects on wall-bounded turbulence. Examples in engineering where turbulence is important are: wind tunnel model testing, numerical prediction of turbulent skin friction drag over an aircraft wing, turbulent forces and acoustic field around a submarine or a road vehicle, and the dispersion of pollutants in the atmosphere. Turbulence may also be beneficial, for example, in improving engine combustion and decreasing pollutant emissions. Hence this study will have national ....Surface roughness and its effects on wall-bounded turbulence. Examples in engineering where turbulence is important are: wind tunnel model testing, numerical prediction of turbulent skin friction drag over an aircraft wing, turbulent forces and acoustic field around a submarine or a road vehicle, and the dispersion of pollutants in the atmosphere. Turbulence may also be beneficial, for example, in improving engine combustion and decreasing pollutant emissions. Hence this study will have national benefits in many scientific fields, for example, in fuel savings (economy and energy ), stability of road vehicles (safety and health), noise generation and acoustic signatures of submarines (transforming defence technology and safeguarding Australia).Read moreRead less
DEVELOPMENT OF NEW NONLINEAR CONTROLLERS FOR TRAJECTORY TRACKING AND PATH-FOLLOWING OF UNDERACTUATED OCEAN VEHICLES. Trajectory tracking control and path-following of underactuated ocean vehicles are not only of theoretical challenging but also important practice. This project is firstly to develop methodologies to design full-state feedback controllers to force the underactuated ocean vehicles including surface ships and underwater vehicles with off-diagonal terms in their system matrices to tr ....DEVELOPMENT OF NEW NONLINEAR CONTROLLERS FOR TRAJECTORY TRACKING AND PATH-FOLLOWING OF UNDERACTUATED OCEAN VEHICLES. Trajectory tracking control and path-following of underactuated ocean vehicles are not only of theoretical challenging but also important practice. This project is firstly to develop methodologies to design full-state feedback controllers to force the underactuated ocean vehicles including surface ships and underwater vehicles with off-diagonal terms in their system matrices to track reference trajectories generated by virtual vehicles, and to follow a predefined path with a desired forward speed. Secondly, we develop methods to design observers to estimate the unmeasured states (velocities) of the vehicles and incorporate with the full-state feedback controllers to have output-feedback observer-based controllers. Lastly, the proposed control design methods are extended to a certain class of underactuated mechanical systems.Read moreRead less
Structure, Dynamics and Control of Wall-Bounded Turbulence. This research has immense impact in engineering and environmental science including aeronautical, mechanical, biomedical engineering, and meteorological science. The energy savings with reduction in carbon dioxide (CO2) emissions resulting from this research and economic benefits will impact directly on global climate change and a sustainable urban environment in Australia. This research will deliver technological advances in complex fl ....Structure, Dynamics and Control of Wall-Bounded Turbulence. This research has immense impact in engineering and environmental science including aeronautical, mechanical, biomedical engineering, and meteorological science. The energy savings with reduction in carbon dioxide (CO2) emissions resulting from this research and economic benefits will impact directly on global climate change and a sustainable urban environment in Australia. This research will deliver technological advances in complex fluid dynamics and instrumentation, in addition to new and exciting training opportunities for future generations of researchers and engineers. This project will secure Australian science and engineering as world leaders in the crucial area of Fluid Dynamics that influences our everyday lives.
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Stochastic Sensor Scheduling in Statistical Signal Processing. In several statistical signal processing applications, due to computational or communication constraints, at each time instant one can use only a few out of several possible noisy (stochastic) sensors. The stochastic sensor scheduling problem deals with how to dynamically choose which group of sensors to pick at each time instant. This project involves research in sensor scheduling for widely used stochastic dynamical systems such as ....Stochastic Sensor Scheduling in Statistical Signal Processing. In several statistical signal processing applications, due to computational or communication constraints, at each time instant one can use only a few out of several possible noisy (stochastic) sensors. The stochastic sensor scheduling problem deals with how to dynamically choose which group of sensors to pick at each time instant. This project involves research in sensor scheduling for widely used stochastic dynamical systems such as Hidden Markov Models and Jump Markov Linear Systems. It focuses on the design and analysis of stochastic control algorithms such as dynamic programming and simulation based randomized methods. The research will lead to an integrated theory incorporating stochastic control, statistical signal processing and combinatorial optimization. We will also apply the resulting techniques to tracking maneuvering targets given noisy observations.Read moreRead less
Optimising the balance between task automation and human manual control. This project aims to discover how best to design automation to maximise performance, while ensuring that operators maintain the task awareness required to manually control previously automated tasks. In environments such as defence and aviation, automating tasks can improve performance, but many accidents have occurred because human operators have not adequately regained manual control when automation has failed. This proje ....Optimising the balance between task automation and human manual control. This project aims to discover how best to design automation to maximise performance, while ensuring that operators maintain the task awareness required to manually control previously automated tasks. In environments such as defence and aviation, automating tasks can improve performance, but many accidents have occurred because human operators have not adequately regained manual control when automation has failed. This project proposes a series of studies using simulations of submarine track management and air traffic control in laboratory and field settings that draw upon psychology and human factors. The project is designed to provide the strategic research that is required to discover how best to adapt the automation currently used in industrial settings.Read moreRead less
Coordination control of underactuated ocean vehicles for ocean forecasting. Australia is surrounded by oceans. Ocean forecasting is essential for effective and efficient operations on and within the ocean for a number of applications such as coastal zone management, military operations and scientific research. The successful completion of this project promises to put Australia in a leading position in this area. Due to the multi-disciplinary nature of this project, the project development will a ....Coordination control of underactuated ocean vehicles for ocean forecasting. Australia is surrounded by oceans. Ocean forecasting is essential for effective and efficient operations on and within the ocean for a number of applications such as coastal zone management, military operations and scientific research. The successful completion of this project promises to put Australia in a leading position in this area. Due to the multi-disciplinary nature of this project, the project development will also stimulate the development in many other areas such as new ocean vehicles, sensors and actuators, electronics and control.Read moreRead less
Forecasting wave breaking in directional seas. Wave breaking in Australia's coastal and open ocean regions has significant consequences for weather forecasting, marine safety, defence and renewable energy, yet no conceptual or computing framework exists for this fundamental process. This innovative project extends our recent advances in predicting wave breaking onset and strength of unidirectional wave groups to forecast breaking in realistic directional wind seas. The results of this project wi ....Forecasting wave breaking in directional seas. Wave breaking in Australia's coastal and open ocean regions has significant consequences for weather forecasting, marine safety, defence and renewable energy, yet no conceptual or computing framework exists for this fundamental process. This innovative project extends our recent advances in predicting wave breaking onset and strength of unidirectional wave groups to forecast breaking in realistic directional wind seas. The results of this project will provide the scientific basis needed to include reliable breaking wave information in forecast models, and will improve their accuracy. It will also increase the international competitiveness of Australian commerce reliant on accurate marine environmental forecasts.
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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