夹沙螺旋管流能耗的试验研究

在水平圆管中设置导叶式起旋器,使管内夹沙水流形成了强制螺旋流,螺旋流可以分解为强制涡流与轴向平直流,前者可起“抬托”泥沙的作用,后者则同普通管道输送固粒一样起输移的作用,这样使本来以推移质形式运动的泥沙较为容易地转变成悬移质。该文应用动量和动量矩定律,对圆管内强制螺旋流的清水与夹沙两种情况进行了理论分析和试验研究,得到的结论是:螺旋管流的能坡可以用达西公式来表达;其夹沙能力远高于同能坡下的平直流情况;在非饱和状态下,附加“旋浮”沙的能坡正比于含沙量

Experimental Study on Energy Gradient of Sediment Transportation in Spiral Pipe Flow

Forced spiral flow can be produced in a circular pipe flow by erecting blades in the pipe. The velocity of spiral pipe flow with sediment can be decomposed into the circumferential vortex flow velocity and the axial flow velocity as normal pipe flow. The former acts as uplifting the sediment and the latter transports it. Therefore the transported sediment with the form of bed load can be changed as suspended load easily. In this paper, with the momentum law and the momentum moment law, the forced spiral flow was analysed and studied in theory and by experiment, which was in two states of clean water and sediment laden water separately. The obtained results are: the energy gradient of spiral pipe flow can be expressed with Darcy's equation; it has more ability of sediment transportation than normal pipe flow at the same energy gradient; the additional energy gradient of uplifting sediment is proportional to the sediment concentration in water. It lays a reliable basis for studying sediment transportation in spiral flow.