Hydrodynamic Simulation of Surface Flow and Sediment Transport Processes

Department of Hydrology & Atmospheric Sciences
Weekly Colloquium
Thursday, April 11, 2019
4:00 pm in Harvill Building Room 101 ~ Refreshments at 3:45 pm
 
Jennifer G. Duan, PhD, PE

Professor

Department of Civil Engineering and Engineering Mechanics

The University of Arizona

Abstract:

CHRE2D is a two-dimensional hydrodynamic and sediment transport model that simulates surface flow routing and sediment transport using numerical solutions of shallow water equations and the kinematic or diffusion wave approximation. The shallow water equations are discretized by the first-order Godunov-type finite volume method. The stability analysis showed that the friction source term increased exponentially as flow depth became very small. This breaks the balance between the friction and the slope source terms.  An approximate solution to the momentum equation, kinematic or diffusion wave approximation, are introduced to compensate this balance.  This technique enables the numerical model is accurate, robust and stable for both very shallow overland (e.g. 10-10 m) and concentrated channel flows. The resulted model is capable of simulating both hydrological flow (e.g. surface flow routing) and hydraulic flow (e.g. dam break), which has not been achieved in similar commercial software, such as FLO2D, ARM2D. Additionally, the CHRE2D model has implemented the Grass-type sediment transport formula to simulate the total sediment load in both overland flow and channel flow. Example applications include the flood frequency curve for the lower San Cruz River incorporating the impacts of climate changes, and the simulation of flood inundation in the Santa Cruz and the Rillito River basins in the unprecedented event in 2006.

Bio:

Dr. Duan received PhD in Computational Hydroscience and Engineering from University of Mississippi in 1998, MS in Hydraulic Engineering from Tsinghua Univ in 1992, and BS in Hydraulic Engineering from Wuhan Univ. in 1989. She was the recipient of NSF CAREER grant in 2009, and served as chair and co-chair of ASCE Technical Committee on Computational Hydraulics, and several tasks committees relating to sediment transport modeling. She is also serving as Associate Editor for Journal of Hydrology.