【摘要】 为研究移动射流冲蚀效果和泥沙输移的影响因素,开展了不同射流喷嘴移动速度和沙床坡度条件下的二维平面移动射流冲蚀沙床试验研究。试验记录了不同射流工况下的泥沙输移过程及异重流的运动规律,分析了泥沙输移及异重流运动随射流喷嘴移动速度、沙床坡度的变化规律,讨论了异重流运动和泥沙淤积形态的物理机制。结果表明:水下移动射流冲蚀沙床能够形成异重流,可实现淤积泥沙的起动并输移一定距离。泥沙淤积轮廓剖面具有相似性,各工况平均输移距离近似相等,沿程累计泥沙相对输移量分布与泥沙粒径分布相似。泥沙相对输移量与射流喷嘴移动速度和沙床坡度呈正相关,但当沙床坡度大于10‰后,坡度影响不再显著。更多还原

【Abstract】 A series of experiments on two-dimensional plane jet erosion sand bed were carried out to study the erosion effects of sand bed by underwater moving jets. The jet movement speed and sand bed slopes were changed. The sediment transportation and density flow under different jet conditions were recorded. According to experimental results, the variation law of sediment transportation and density flow movement with jet movement speed and sand bed slope were analyzed. The physical mechanisms of the two-phase flow movement and sedimentation morphology were discussed. Results show that the moving jet erosion of sand bed formed density current, which could induce sediment incipience and transport a certain distance. The sediment deposition profiles after the erosion were similar, and the averaged transport distances in all conditions were approximately equal. There was similar relationship between accumulated relative sediment volume distribution and sand particle size distribution. The relative amount of sediment transport was positively correlated with the jet moving speed and the sand bed slope, but when the slope was greater than 10 ‰, the slope effect was no longer significant.更多还原