排沙漏斗中的二次流及其影响

根据理论分析和现有试验成果相结合的方法,研究了排沙漏斗中二次流在排沙中的重要作用。应用二次流理论解释了一些排沙漏斗结构设计的内在原因,从二次流的角度去说明排沙漏斗是如何实现高效排沙的,得到了一些被试验和实践证实了的结论。着重地阐述了排沙漏斗在处理以悬移质为主的泥沙和以推移质为主的泥沙时排沙漏斗直径大小调整的原因。提出了平衡悬移质所需的水流临界径向速度公式,它为定量地判断水流能否向中心输移悬移质颗粒提供参考。

The Secondary Flow in Sand Funnel and Its Influence

Combining the theoretical analysis and the existing experimental achievement,the important role of secondary flow for sediment ejection in sand funnel is researched for the first time.Some inner causes of sand funnel structural design are explained using the secondary flow theory.How sand funnel achieves highly effective sediment ejection is discussed from the angle of secondary flow,and some conclusions from the experiment and practice are drawn.The paper analyzes emphatically the reason about size adjustment of sand funnel when it is dominated by suspended load or dominated by bed load.A formula of current critical radial velocity needed by balancing suspended load is put forward,it provides a reference to quantitatively judge whether the current could transport suspended sediment to the bottom hole.