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当挟沙水流进入清水时,在特定的条件下会潜入底部向前运动,形成浑水异重流。水库水温分层使得水体密度在垂向出现差异,低含沙量浑水形成的异重流与周围水体密度接近,因而在运动过程中会受到垂向温度分层的干扰。浑水异重流是泥沙运动的特殊形式,还可能改变环境水体的温度,是水库调水调沙必须考虑的因素。该文应用水槽试验结合数值模拟,探究了水温分层条件下低含沙量异重流的运动规律及其对水温分布的影响。结果表明,异重流潜入点处形成回流,交界面以下含沙量以均匀梯度增加,前锋运动速度沿程不变;中层异重流不改变水温分布,而底层异重流则会对水温结构造成破坏,使得水温分布由分层型转变为混合型。
When the sediment-laden water flow into the clear water, under certain conditions will dive into the bottom of the forward movement, the formation of a different flow of muddy water. The stratification of water temperature causes the water density to vary in the vertical direction. The heavy gravity flow formed by muddy water with low sediment concentration is close to the density of the surrounding water. Therefore, it will be disturbed by the vertical temperature stratification during the movement. Muddy water gravity flow is a special form of sediment movement, but also may change the temperature of ambient water, which is a factor that must be taken into account when adjusting water and sediment in reservoirs. In this paper, with the combination of numerical simulation and sink test, the law of motion of heavy sediment with low sediment concentration and its effect on water temperature distribution are studied. The results show that the return flow at the inflow point of gravity flow is formed, the sediment concentration below the interface increases with a uniform gradient, and the velocity of the forward movement does not change along the course. The isoparametric flow does not change the water temperature distribution, Causing damage, making the temperature distribution from stratified to mixed type.