DONG Xing-lin, YANG Kai-lin, FU Hui, WANG Tao (China Institute of Water Resources and Hydropower Research, Beijing 100038, China)

Abstract: Based on the ideas of swirling flow cavitation mitigation, energy dissipation, atomization prevention and environment protection, a new flood discharge structure which composed of a swirling device of morning glory shaft spillway and a deep intake has been developed. Its remarkable characteristics are that the flood release as well as desilting or water transport to downstream for emptying the reservoir share the same shaft and diversion tunnel. Thus it has a simple structure and is more reliable and economic. The design principles and samples of such structure are systematically presented, including the deep intake has been involved in flood discharge or not. In this paper, a double-inlet spillway tunnel is created by optimizing the previous project to substitute the traditional scheme with two spillways. As a result, a lot of investment is saved. Because the swirling device is designed in both the trumpet-shaped inlet and a deep intake, a swirling flow with the air core and the annular jet central ventilation occurs in the shaft spillway to mitigate the negative pressure in the shaft and the spillway and prevent from cavitation, improving the energy dissipation efficiency and avoiding the atomization.

Key words: submerged blocks of spiral flow generator, morning glory shaft spillway, deep intake, vortex Shaft

Published in: Journal of Hydraulic Engineering, Vol. 43, No. 8, 2012