Shengyang Chen

BE(HNU), MEngSci(UNSW)
Postgraduate Research Student
Environmental Fluids Group



School of Civil Engineering, Room 101
Phone: +61 2 9351 5155
Fax: +61 2 9351 3343
Email:

Research project - Particle transport and mixing in reservoirs and lakes

Supervisor: A/Prof Chengwang Lei

The aim of this project is to understand the significant driving mechanisms responsible for the transport and mixing of pollutant particles within water bodies. The driving mechanisms of interest may include the natural inflow and outflow, stratification between upper and lower levels, or diurnal heating and cooling. The research result could be used for water management.

The inflow into reservoirs from sidestreams would contain nutrients and pollutants particles thereby resulting in mixing of these substances in water bodies. To research on the fate of these substances would help us to understand the time variation of the water quality in the reservoirs. The driving force of the transport and mixing may involve several dynamical processes. The most important one would be the circulation between the shore and central regions due to diurnal heating and cooling and its interaction with the geometry. As a consequence, lateral temperature gradients are established which then drive a convection flow carrying the substance of interest. The convective flow and the consequent transport of the particles within the reservoirs will be modelled using commercial software.

This project will base on the existing triangular cavity model (Bednarz, Lei et al. 2009), which has been studied experimentally and numerically in depth for the natural heating and cooling effect from the surface of the water body within the environmental fluid group at University of Sydney (see the figure 1). This project will be extended by the injection of pollutant; and the numerical result from this injection should reflect trajectories of these particles; then the quality of water could be predicted under the specific situation.

Fg1. Isotherms at the transitional stage for Gr = 107 and Pr = 7.07. (a) t = 220 s, (b) t = 300 s, (c) t = 400 s, (d) t = 800 s, (e) t = 1200 s, (f) t = 1800 s (Bednarz, Lei et al. 2009)

This project is aiming to provide detail information of the consequence of the contaminant for water quality management at water filtration plant. This will be useful for management teams to setup a precautionary monitoring method for drinking water supply systems according to Australian drinking water guidelines (ADWG, 2004, chapter 3). By understanding the contaminant dispersion processes within reservoirs, the processes of water filtration plant can be adjusted accordingly thereby optimising the treatment processes to reach the required water quality in water supply.


Reference
Bednarz, T. P., C. Lei, et al. (2009). "A numerical study of unsteady natural convection induced by iso-flux surface cooling in a reservoir model." International Journal of Heat and Mass Transfer 52(1–2): 56-66.