Vol16 No.8: 1913-1927
【Title】Dynamic hydraulic jump and retrograde sedimentation in an open channel induced by sediment supply: experimental study and SPH simulation
【Author】ZHENG Xiao-gang1; CHEN Ri-dong1; LUO Min2*; KAZEMI Ehsan3; LIU Xing-nian1
【Addresses】1 State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu 610065, China; 2 Zienkiewicz Centre for Computational Engineering, College of Engineering, Swansea University, SA1 8EN, UK; 3 Department of Civil and Structural Engineering, University of Sheffield, Sheffield S1 3JD, United Kingdom
【Corresponding author】LUO Min
【Citation】Zheng XG, Chen RD, Luo M, et al. (2019) Dynamic hydraulic jump and retrograde sedimentation in an open channel induced by sediment supply: experimental study and SPH simulation. Journal of Mountain Science 16(8). https://doi.org/10.1007/s11629-019-5397-8
【Abstract】Mountainous torrents often carry large amounts of loose materials into the rivers, thus causing strong sediment transport. Experimentally it was found for the first time that when the intensive sediment motion occurs downstream over a gentle slope, the siltation of the riverbed is induced and the sediment particles can move upstream rapidly in the form of a retrograde sand wave, resulting in a higher water level along the river. To further study the complex mechanisms of this problem, a sediment mass model in the framework of the Smoothed Particle Hydrodynamics (SPH) method was presented to simulate the riverbed evolution, sediment particle motion, and the generation and development of dynamic hydraulic jump under the condition of sufficient sediment supply over a steep slope with varying angles. Because the sediment is not a continuous medium, the marker particle tracking approach was proposed to represent a piece of sediment with a marked sedimentparticle.The two-phase SPH model realizes the interaction between the sediment and fluid by moving the bed boundary particles up and down, so it can reasonably treat the fluid-sediment interfaces with high CPU efficiency.The critical triggering condition of sediment motion, the propagation of the hydraulic jump and the initial siltation position were all systematically studied. The experimental and numerical results revealed the extra disastrous sediment effect in a mountainous flood. The findings will be useful references to the disaster prevention and mitigation in mountainous rivers..
【Keywords】Dynamic hydraulic jump; Retrograde sedimentation; Sediment supply; Mountainous river; Smoothed Particle Hydrodynamics; Marked sediment particle