盲肠河段的水位波动

Oscillating Unsteady Flow in Sidearms

本文通过数值模拟及摄动分析，对平面形状为矩形（简称小包方案）及平面形状为曲边梯形（简称大包方案）的两种盲肠河段的水位波动进行了研究。结果表明，无论是小包方案还是大包方案，当口门处波源的波动周期与盲肠河段的固有周期相近时，都会发生共振现象。某大型水利枢纽上引航道的两种不同布置方案数值计算结果比较表明，在不同口门水位波动幅度及周期条件下，小包方案的水位波动幅度均较大包方案大，特别是盲肠河段内的水位波动发生共振时，大包方案的水位波动幅度远较小包方案的小，说明大包方案对削减盲肠河段内的水位波动及改善船舶的航行及停泊条件是非常有效的。摄动分析结果表明，在盲肠河段的长度与水深相同的条件下，发生共振时，大包方案的共振周期较小包方案长。大包方案的水位波动具有随离开口门的距离而减小的特性，而小包方案的水位波动则不随离口门的距离而变。

In this paper numerical simulation and theoretical analysis are used to study the wave in two different types of sidearm,one is a rectangular channel,another is a trapezoid channel. The study shows that resonance wave could be generated in both rectangular and trapezoid channels,when the period of water level change outside the sidearms closes to the natural period of the sidearms. The numerical simulation of flow in the two type of sidearms shows that the wave height at the rectangular channel is much larger than that in the trapezoid channel,exceptionally when the resonance wave initiated. The perturbation solutions show that the period of the flow in the rectangular channel is shorter than that in the trapezoid channel,the wave height decays with the distance from the opening end in the trapezoid siderms,but not in the rectangular sidearms.