床面上短柱体局部冲刷的机理复杂,运用三维有限体积法,对其局部冲刷情况进行了模拟。采用k-ε紊流数值模型,计算柱体周围的紊动流场,利用经验公式计算该时刻的推移质输沙率,运用动网格技术,处理床面地形随时间的变化。推移质计算充分考虑了床面坡度和流向对推移质输沙率和临界起动剪切力的综合影响。改进沙滑模型,修正当生成的剖面坡度超过泥沙休止角时造成模拟的失真,同时克服数值计算的不稳定性。计算结果和水槽试验资料对比分析,二者符合较好。该模型可以用于海底结构物如桥墩、管道、丁坝等的局部冲刷的数值模拟计算。
Mechanism of local scour around short cylinder is complex. With 3-D finite volume method, a numerical model for time dependent local scour around the short cylinder is developed. The k ? εturbulence model is used to compute the flow field. The bed-load transport rate is computed by an empirical formula related to the bed shear stress. The scour model is implemented taking advantage of the dynamic mesh. The influences of bed slope on both sediment transport rate and critical bed shear stress is fully conside...