Author: DONG Xing-lin, YANG Kai-lin, GUO Xin-lei, GUO Yong-xin (China Institute of Water Resources and Hydropower Research, Beijing 100038, China)

Abstract: According to the swirling flow mechanism, a novel shaft spillway which consists of submersible blocks of spiral flow generator and flared weir was developed. The stable and swirling flow with air core in the vertical shaft can be generated under a variety of weir water head possille to eliminate negative pressure and to prevent cavitation. Besides, the energy dissipation ratio of the shaft spillway was increased significantly. The flow mechanism of this novel spiral flow blocks is that when the water head above the weir is low, the water will flow to the vertical shaft along the block wall, and the stable and swirling flow with air core will be generated; however when the water depth was significantly raised over the top of blocks, the inflow angle will automatically adjust under the action of inertial forces which leading to the larger discharge capacity, and meanwhile, the water flow will be synchronously swirled under the drag force of bottom flow. The design theory and the research results was applied to the shaft spillway of Qingyuan Pumped Storage Power Station in Guangdong province.

Key words: swirling flow; morning glory shaft spillway; submersible blocks of spiral flow generator

Published in: Journal of Hydraulic Engineering, Vol. 42, No. 1, 2011

Article ID: 0559-9350 (2011) 01-0014-05