Vol19 No.7: 1874-1885
【Title】Phenomenon of the sediment deposition in a hydraulic jump region of open channels
【Author】XU Wei-lin*; WANG Guo-guang; FU Shi-hao; WEI Wang-ru
【Addresses】State Key Laboratory of Hydraulics and Mountain River Engineering, Sichuan University, Chengdu 610065, China
【Corresponding author】XU Wei-lin
【Citation】Xu WL, Wang GG, Fu SH, et al. (2022) Phenomenon of the sediment deposition in a hydraulic jump region of open channels. Journal of Mountain Science 19(7). https://doi.org/10.1007/s11629-021-7067-x
【Abstract】The hydraulic jump is a typical sudden change for mountain river areas. The effects of local hydraulic jumps on the particle transport capacity decrease and local flow resistance increase cannot be ignored as the sediment deposition disaster can amplify the flash flood disaster. The present research investigates the influences of a hydraulic jump on the individual particle movement and sediment deposition in a laboratory flume. The overall processes of a single particle movement are captured by a high-speed camera. The distribution of sediment deposition along the hydraulic jump is obtained statistically. The results show that both the particle size and the ratio of the upstream and downstream Froude numbers affect the particle motion process. A single particle coming from upstream gradually decelerates and finally stops at the hydraulic jump section because of hydraulic jump resistance. The particle acceleration first increases and then decreases during the time-domain process, and the attenuation trends are fast with the increase of ratio of upstream and downstream of Froude numbers. The increase of the maximum acceleration with sediment flows follows a linear trend approximately, which indicates that the kinetic features of the single sand particle are determined by the coupling effects of the hydraulic jump resistance and the sand dynamic properties. With the increase of sediment rate and sand particle size, the resistance effect of hydraulic jump on sediment deposition rate along the flow direction gets strong and the sediment deposition area is mainly located upstream of the hydraulic jump region. The present study shows that the possible sediment supply upstream must be obtained for identifying the disaster risk combined with the local hydraulic jump conditions. Further researches about the detailed critical condition deduced from the relationship between the water flow and sediment deposition are required to confirm and extrapolate present results to other applications.
【Keywords】Ratio of upstream and downstream Froude numbers; Hydraulic jump; Particle size; Sediment deposition