低弗劳德数水流辅助消能工空蚀问题研究

Study on cavitation damages of supplementary dissipater under low-Froude-number flows

辅助消能工的空蚀问题是水利工程中重点关注的问题之一。本文针对水利工程中常遇到的消力墩表面空蚀破坏问题进行了试验研究,提出通过两种方法解决空蚀问题:采用消力池+不完全宽尾墩+消力墩联合消能工和圆化消力墩棱角。试验结果表明:采用联合消能工不仅能够减小底流流速、减轻水流对消力墩的冲击力,而且能够提升消力墩表面的空化数、有效提高消能率。适当圆化消力墩棱角可以降低初生空化数;还能减轻紊动、提升空化数,从而提高消力墩的抗空蚀能力。

Cavitation damage of supplementary dissipater is a key problem of hydraulic structures that has drawn much attention and study efforts. This paper focuses on an analysis of the experimental tests on cavitation and cavitation damages of supplementary dissipaters in common use. We describe two measures against cavitation damage： a combined energy dissipater of stilling basin, incomplete flaring gate piers, and baffle piers; baffle piers with smooth rounded edges. The results show that this combined dissipator can reduce the flow velocity near the bottom and the forces on baffle piers, increase cavitation number of the baffle piers, and improve the rate of energy dissipation effectively. If its edges are rounded appropriately, a baffle pier will has a lower incipient cativition number, the turbulent motions behind it are weakened, and its cavitation number is increased, improving its resistance against flow cavition.