Viscous extensional flow and drop breakoff. Honey falling from a spoon is an everyday example of a viscous fluid in a free extensional flow which may eventually break up into drops. Such flows are important in modern technologies including ink-jet printing, welding, soldering and molten metal processing, polymer and glass fibre spinning, and for rheological measurement. We seek to increase understanding of the mechanisms governing such flows, particularly the role of initial conditions and the ....Viscous extensional flow and drop breakoff. Honey falling from a spoon is an everyday example of a viscous fluid in a free extensional flow which may eventually break up into drops. Such flows are important in modern technologies including ink-jet printing, welding, soldering and molten metal processing, polymer and glass fibre spinning, and for rheological measurement. We seek to increase understanding of the mechanisms governing such flows, particularly the role of initial conditions and the geometry of the original containing vessel, together with balances between forces such as inertia, gravity, viscosity, viscoelasticity, and surface tension, through a theoretical, computational and experimental study of the fluid mechanics.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