管线振荡绕流对砂床的冲蚀

采用轻质模型砂在带砂槽的Ｕ型振荡水槽中对振荡流中管线下方的砂床冲蚀进行了实验研究，给出了管线下方砂床的平衡冲蚀深度随Ｋｃ数的变化规律以及发生冲蚀的临界ｅ／Ｄ和Ｋｃ的相关，并指出管线的存在使砂床开始形成砂波相应的振荡流临界振幅值下降．

SCOUR OF THE SAND BED BELOW THE PIPELINE INOSCILLATING FLOW

The Scour of the bed below a pipeline in oscillating flow is studied experimentally ina U-Shaped water tunnel with a sand box at the bottom of the test section. The artificial plasticsand is used as bed material. The relationship between the maximum equilibrium scour depth andKc number, and the relationship between the critical gap above which no scour occurs and Kcnumber are obtained. It is shown in this test that the critical amplitude in the presence of thepipeline at which the sand wave is formed is smaller than the one when the pipeline is absent.