粘土悬浮液明渠流的减阻现象

水和粘土悬浮液在水槽中的流动试验证明，在粗糙边界上的粘土悬浮液明渠流阻力明显小于清水流．在同样水力条件下粘土悬液的时均流速比清水流速大得多．当悬液浓度较高时，流动阻力系数比清水流阻力系数的一半还小．实验表明粘土悬液的高粘性和屈服应力抑制了紊动的发展，减小了紊动剪力，导致阻力降低．对于光滑边界湍流，粘土悬液的阻力系数与清水流的相近，不发生减阻现象     

非牛顿体不稳定流的研究

本文通过试验和分析研究了非牛顿体明渠不稳定流的机理,阐明了不稳定流的产生和发展是由于流体具有屈服应力,利用这一机理,解释了高含沙洪水的波动和“浆河”现象、冰川流和泥流的不稳定流和泥石流的阵流现象。     

The effect of suspension on mean velocity profile

The vertical gradient of suspended sediment concentration often exists in estuarine and coastal regions. The existence of such concentration gradient, particular that of cohesive suspended sediment concentration gradient, affects the flow velocity profile. Based on the wave-current full depth combined model, k-ε turbulent model is employed in this paper to simulate the effect of sediment concentration on the wave-current flow. A quantitative analysis of change mechanism of mean velocity profile is presented. The results show that the change mechanism of Eulerian mean current velocity under clear water is different from that under sediment-water mixed flow.     

层移质运动规律的实验研究

高浓度水沙两相流当颗粒浓度超过一定极限后,紊动消失,进入层移质运动。本文通过用管道输送无粘性沙的试验,对层移质运动的流速分布,阻力损失及离散力进行了初步探讨。     

粗颗粒高含沙两相紊流运动规律的实验研究

本文通过在矩形断面水平管道中的输沙试验,研究了粗颗粒二相高含沙水流的流速及含沙浓度分布。在主流区,流速分布遵从对数规律,卡门常数则为利查逊数及浓度的函数。底床附近,流速分布受到升力效应的影响。管道高含沙水流的悬沙浓度分布与明渠低含沙水流大不相同,利用扩散方程求出浓度分布公式,与实测结果符合得很好。     

大气边界层的风洞模拟

本文通过比较大气边界层与不同比尺的模型实验，研究了风洞模型实验中的比尺效应。结果表明，大气边界层粗糙高度的比尺应当和边界层厚度比尺相等。边界层厚度的比尺在２００～４００之间时可以得到最好的速度分布的相似性，表面压强分布主要依赖于边界层比尺而与建筑物几何比尺关系不大。如果正确选择了粗糙高度比尺，扩散系数比尺和边界层厚度比尺相同。     

Flood control and shrinkage in the Haihe River Mouth

Because of overusing water resources in the upper and middle reaches of the Haihe Basin, less and less water flows to the river mouth. The Haihe River flow is cut off in most time of the seasons, sediment deposited in the river mouth channel is rarely scoured away, and many of the river mouth channels have been shrinking quickly. The discharge capacity of the channel is consequently reduced greatly, which results in more and more serious flood hazard. Many tide gates have been built for storing fresh water and preventing the salty and turbid water. The channel downstream of the gate is silting up and people have to dredge the channel every year before the flood season. This paper studies the laws of the siltation and strategies controlling channel shrinkage. The strategies are digger dredging, trailer dredging, scouring with pumping water or storing tidal water, building double guiding dikes and building a new gate. Comparison of various strategies is performed, suggesting the most effective strategy con