Research_

Our research

Broad research in the areas of energy, water and environment

We facilitate collaboration between expert researchers and a diverse range of industry partners to cover a wide array of research initiatives related to fluid mechanics.

Our key research focuses on: 

Wind engineering

Wind engineering analyses the effects of wind in the natural and built environments, and examines the inconvenience or benefits which can result.

Our research in this field covers wind load on structures, aerodynamics of structures, pollutant dispersion in urban environments, pedestrian wind comfort, wind energy, aerodynamic design of buildings and turbulent boundary layers.

Our experts: Professor Kenny Kwok

Our collaborators: Western Sydney University

Laboratory: Boundary Layer Wind Tunnel

This research will advance our understanding of bushfire-wind interaction and raise awareness of bushfire-enhanced wind storms as a major bushfire attack mechanism. The outcome of this research will revolutionise current design standards for buildings against bushfire-enhanced winds. The new generation of bushfire and wind-resistant buildings will provide improved safeguards against property and human losses, thus reducing the economical and emotional impacts of post-bushfire reconstruction.

Our experts: Professor Jianlei Niu, Dr Kapil Chauhan, Dr Murali Talluru, Professor Kenny Kwok

Our partners: This is a collaborative research fund (CRF) project involving four universities in Hong Kong.

Laboratory: Boundary Layer Wind Tunnel

Widespread use of air-conditioning in indoor built environments is the major culprit of many of today’s environmental problems. Therefore a city that encourages outdoor activities has to accommodate both sustainability and liveability. While urban heat islands (UHI) phenomenon is not new, its adverse impacts and scale are becoming unprecedented due to rapid urbanisation, particularly in Asia. This forces people to stay indoors for longer and encourages urban planners and property developers to provide more air-conditioned indoor facilities, further aggravating the problems in a vicious cycle.

The intended outcome is systematic understanding of the local wind and thermal comfort conditions in real life and their influence factors, insight into the generic airflow and turbulence structures of several typical building forms, and evaluation of the detached eddy simulation (DES) turbulence model.

Our experts: Professor Kenny Kwok

Our partners: Western Sydney University

Laboratory: Boundary Layer Wind Tunnel

Current building motion design guidelines primarily focus on motion perception and complaint rates. However, wind-induced building motion can cause sopite syndrome or early onset motion sickness which adversely affects occupant wellbeing and work performance.

This research will advance the understanding of the physiology of sopite syndrome, quantify the motion dosage that causes sopite syndrome and determine its adverse effects on building occupants in real-world motion environments. This knowledge will guide the formulation of building motion acceptability criteria based on safe motion exposure duration to facilitate the design of tall building that promotes population health and wellbeing and lifts work performance and productivity.

Thermo-fluid mechanics

Thermo-fluid mechanics studies the fundamental and applied problems related to energy conversion, heat and mass transfer, combustion and fluid mechanics.

Our research in this field includes: buoyancy driven flows, natural convection boundary layers, natural ventilation, gravity currents and heat transfer enhancement.

Our experts: Professor Chengwang Lei, Professor John Patterson

Our partners: Shanghai Jiao Tong University

Laboratory: Convection Laboratory

The project aims to fill in a gap in the study of laminar to turbulent transition of thermal boundary layer (TBL). The state of the TBL determines the heat transfer rate and energy efficiency of natural convection heat exchangers and heat dissipation systems. The intended outcome is advanced understanding of the transitional behaviour of the TBL and effective strategies for stimulating TBL transition to enhance heat transfer.

 

Our experts: Professor Steven Armfield, Associate Professor Michael Kirkpatrick, Professor Chengwang Lei, Professor John Patterson

Laboratory: Convection Laboratory

Conjugate natural convection boundary layers occur when a conducting vertical wall separates two fluids at different temperatures, with thermal boundary layers developing on both sides of the wall. Such configurations occur frequently in industrial and environmental flows. The heat transfer across the wall depends in part on the state of flow of the two boundary layers. Heat transfer across turbulent boundary layers is much greater than that across laminar boundary layers, and an understanding of the factors which lead to transition to turbulence, and other unsteady effects, is crucial in optimising the heat transfer.

Sustainable building technologies

The design, development and performance of sustainable buildings involve the use of a wide range of technologies, including innovative and advanced materials, and building services equipment.

Our research in this field includes: natural ventilation, solar chimney design optimisation, night-time ventilation and other solar thermal technologies.

Our experts: Professor Jianlei Niu, Dr Yixiang Gan, Professor Chengwang Lei

Our partners: Petroleum refinery and chemicals industry

Laboratory: Environmental Laboratory

Current thermal energy storage (TES) utilises water and ice for building heating and cooling applications, which suffer from either low storage capacity or low energy efficiency problems. Phase-change material (PCM) offers many new potentials, but the limited heat transfer rate remains one of the key challenges that hinders the application of these potentials.

The aim of this project is to use highly thermally-conductive materials to enhance the equivalent heat conductivity of a PCM so that the charging and discharging rate can be flexibly regulated in the application process. The outcome of this project will be a new generation of TES materials and designs that will help promote the wider use of solar energy for building and heating applications, greatly cutting the carbon foot printing of building stocks.

Environmental flows

Environmental flows describe the quantity, timing and quality of water flows required to sustain freshwater and estuarine ecosystems, and the human livelihoods and wellbeing that depend on these ecosystems.

Our research in this field includes: exchange and mixing in reservoirs, nutrients and pollutants transport, oxygenation and destratification systems, and fluid biological interactions.

Our experts: Professor John Patterson, Professor Chengwang Lei

Our industry partners: University of California, Santa Barbara

Laboratory: Fluids LaboratoryConvection Laboratory

Nutrients, pollutants, biological and other materials are carried into lakes and reservoirs primarily from the shore. These materials are distributed by a range of physical processes, one of which is the motions set up by horizontal temperature gradients resulting from unequal heat capture and losses. These arise because the heat transfers from solar radiation and other heat fluxes at the surface are approximately uniform spatially; however the depth decreases towards the shore. This results in greater volumetric heating (daytime) or cooling (night time) so that the shallow part becomes warmer/cooler than the deeper part. Further, some residual radiation reaches the bed and is remitted as a heat flux (which may give rise to instability) and rising plumes. These complex motions are studied experimentally and with numerical, analytical and stability analyses.

Environmental modelling

Environmental modelling improves the understanding of natural systems and how they react to changing conditions, such as exposure to hazardous substances, and the temporal and dose effects from the exposure.

Our research in this field includes: hydraulics and hydrology, soil biogeochemistry, sediment-microorganism-water interaction, soil-plant-atmosphere interaction, and climate, water and soil change.

Our experts: Dr Federico Maggi, Ms Chiara Pasut

Laboratory: Environmental Laboratory

The aim of this project is to develop computational models to track the contaminants (agrochemicals and salinity) in different environmental conditions and assess bioremediation and phytoremediation potentials in soil. Model outcomes will be supported by laboratory experiments.

Coastal and ocean engineering

Coastal and ocean engineering involves the study of physical processes and construction within the coastal zone and at the shoreline and in offshore areas. This includes investigating aspects of physical oceanography, marine geology and engineering often directed for protection and safety purposes.

Our research in this field includes: nonlinear water wave dynamics, modelling and prediction of extreme wave events, hydrodynamic power generation, as well as sediment transports and scour.

Our experts: Associate Professor Amin Chabchoub

Laboratory: Fluids Laboratory

Extreme waves in the ocean can reach heights up to 35 metres and as such, represent a significant threat to coastal, offshore and navigation operations. Our research aims to model their dynamics in laboratory environments, assess their impact and predict their formation.

Our experts: Associate Professor Amin Chabchoub

Laboratory: Fluids Laboratory

Our research aims to investigate the fundamental behaviour of waves in shallow water regimes. This includes experimental modelling and validation of tidal bores and tsunami-type waves.