Research Abstracts Online
2008 - March 2009
University of Minnesota Twin Cities
Institute of Technology
Department of Civil Engineering
PI: John S. Gulliver
Two-phase Transport in Turbulent Environmental Flow
These researchers are involved in three projects investigating turbulent flow. The first concerns the excess water discharged from hydraulic structures such as dams as reservoirs. The water is usually discharged as a high velocity jet into a relatively stagnant pool that creates a turbulent mixing and recirculation zone. The resulting bubbles affect gas concentrations in the water, which in turn can affect fish in the pool with a disease similar to the bends. The main goal of this project is to evaluate the performance of existing turbulent models (Reynolds averaged navier-Stokes model and large-eddy simulation model) in simulating bubble-water mass transfer.
The second project concerns hydrodynamic separators, which are prefabricated, small-scale, underground structures designed to remove particulate pollutants from storm-water runoff and improve water quality. The effectiveness of hydrodynamic separators has historically been evaluated with monitoring, but the results of these evaluations vary substantially and do not provide adequate predictive models for these devices. A methodology has recently been developed for controlled testing that produces more accurate results as compared to monitoring. These researchers use two- and three-dimensional modeling software with computational fluid dynamics (CFD) to simulate fluid dynamics and sedimentation for several hydrodynamic separators.
The third project uses CFD modeling software to examine turbulent mixing in pipes. The goal of this research is to develop a practical mechanism for mixing the suspended sediment transported in the lowest portion of the flow column in existing stormwater conduits. Well-mixed conditions are critical for accurately stormwater particles—such as sands and coarse silts—as well as the host of pollutants associated with these particles.
Greg DeGroot, Graduate Student
Andy Erickson, Research Associate
Md Shafayat Jamil, Graduate Student