含沙量对U型渠道水流流速横向分布律的影响

探索含沙量变化对U型渠道水流流速沿横向分布的影响,进而从理论上完善挟沙水流流速分布规律,对渠道水沙运动规律的研究有重要意义。引入指数流速分布公式,通过U型渠道水槽试验,测定水流中含沙量为1.12～500kg/m3时,指数公式中流速横向分布系数的变化规律,说明U型渠道挟沙水流流速沿横向分布遵循指数流速分布规律。在含沙量s<300kg/m3下,流速横向分布系数随着含沙量的增大呈线性缓慢增大,当含沙量s≥300kg/m3时,流速横向分布系数由缓慢增大变为急剧增大,说明水流流型已发生了变化;含沙量s≥50kg/m3时,U型渠道的中心出现了核心区,核心区随着含沙量的增大而变宽。

Effects of sediment concentration on lateral distribution of water velocity in U-channel

Effects of change of sediment concentration on lateral velocity distribution in U-Channel if important to theoretically perfect velocity distribution of sediment-laden flow and study on water and sediment movement in channel. Introducing index formula for velocity distribution, changes of the coefficient k, z of index formula when the sediment concentration is 500-1.12 kg/m3 in flow were investigated by the flume experiments in U-Channel, illustrating that lateral velocity of sediment-laden flow follows index formula of velocity distribution in U-Channel. In the case of s<300 g/m3, k, z increased linearly and slowly with sediment concentration increasing, and for s300 kg/m3, changes of k, z was from slowly increasing to sharply increasing. It is observed that when sediment concentration s 50 g/m3, the center of U-channel appeared core area, and the core area broadens as increasing of sediment concentration.