Environmental fluid mechanics

The Environmental Fluid Mechanics Laboratory has been developed to investigate complex turbulent mixing and exchange problems with a particular focus on stable/unstable density stratified environmental flows. The laboratory is fully equipped with PIV/LIF laser diagnostic tools, LDA and high sensitivity cameras. The laboratory has a number of large flumes developed to simulate at a laboratory scale, river flow, stably/unstably stratified boundary layers and negatively buoyant jets. These themes are ongoing interests for the group.

  • Entrainment across a two-layer density interface
    Many inland Australian rivers are affected by rising saline ground water, which forms hyper-saline pools in the bottom of deep scour holes on river bends in periods of low flow. This leads to a two-layer stably stratified shear flow with fresh water flowing over the top of more dense saline water. The overarching goal of this work is to develop analytical tools that will enable catchment managers to predict flow response to an environmental release. These require understanding of what the turbulent entrainment mechanisms are and how they are related to flow stability.
  • Thermal stratification, overturning and mixing in riverine environments
    Australia’s lowland rivers are particularly prone to thermal stratification due to our hot, dry and sunny climate with its propensity for lengthy periods of drought. The resulting increase in flow stability inhibits turbulent mixing and leads to low levels of dissolved oxygen and the accumulation of contaminants. Using numerical simulations and laboratory experiments we are investigating the processes which can breakdown this stable stratification including wind, night-time surface cooling, shear from the river bed, and circulation due to river bends. Again, the aim here is to develop predictive tools that can be used to better manage Australia’s water resources. DNS Simulation of riverine flow with solar heating - Temperature field

    DNS simulation of riverine flow with solar heating - vorticity field

    Direct numerical simulation of riverine flow with solar radiative heating through the upper surface – temperature (upper) & vorticity fields (lower).

  • Negatively Buoyant Jets
    Volcanic eruptions, building ventilation and brine discharge from desalination plants are all examples of the occurrence of turbulent fountains and negatively buoyant jets. Management and design of these processes requires the ability to accurately predict these flows and, in particular, entrainment and mixing with the ambient fluid. We examine the turbulent structure of fountains and negatively buoyant jets using numerical simulation and laboratory experiments.