凹岸边坡型式对急弯河道水力特性影响的数值模拟.

To study the effect of the outer bank slope types on the hydraulic characteristics in sharp bends, a threedimensional hydrodynamic mathematical models was developed to simulate the flow structures under different slope types of the outer bank in the Shishou sharp bend section of the Jingjiang reach. The results show that, with the same cross-sectional area and water depth, the gentler the slope can move the maximum longitudinal velocity and the outerbank reverse secondary flow away from the outer bank and the riverbed. The gentler slope can also decrease the turbulence intensity and the main secondary flow scale. Comparing to the simple and composite riverbank with the same slope, the maximum longitudinal velocity remained almost the same but the main secondary flow scale increased and the pairing model of secondary flow were changed. The maximum shear force on the composite riverbank was 1. 2 times larger than that on the simple riverbank, and thus, the composite riverbank was more vulnerable to erosion and damage. Moreover, the turbulence in the upstream of apex of bend was weakened, while in the downstream of apex of bend was intensified. The results can deepen our understanding of the effect of bank slope types on the flow structure in sharp bends, and provided a basis for the protection of different types of bank slope. [ABSTRACT FROM AUTHOR]