射流冲刷沙床初始阶段的SPH方法数值模拟

Numerical simulation of SPH method of scouring sand bed by submerged water jets in initial phase

针对射流移动清淤时短时间内的冲刷效果问题,采用无网格光滑粒子动力学方法(SPH),对平面垂直淹没射流冲刷沙床的初始阶段进行了模拟计算。探讨了SPH中淹没环境和沙土材料的建立方法,研究了射流冲刷初始阶段动态冲坑深度的发展趋势,分析了射流速度对冲坑深度发展的影响。结果表明:采用SPH方法可以有效地模拟射流冲刷的过程;在初始阶段,冲坑深度随时间线性增加,而且随着射流速度的增加,坑深增加的速率加快。本文研究可为探讨疏浚射流破土效果提供数值方法参考。

Aimed at the effect of scouring by moving water jets in a short time during the desilting process of sediment,this paper used smoothed particle hydrodynamics（ SPH） to simulate the initial phase of scouring on sand beds by submerged plane vertical water jets. It discussed the method of building the submerged condition and the sand material in SPH,studied the development trend of dynamic scour depth and analyzed the effect of the jet velocity on scour hole depth. The result indicated that SPH method can effectively simulate the process of scouring by submerged water jets. In the initial phase,the scour depth increases linearly with time,and accelerates with the jet velocity. This study can provide a reference of simulation method for investigating the effect of soil failure by dredging water jets. Keywords：