Abstract: Problems such as cavity backwater and short dimension are usually found in the aeration devices of spillway tunnel with high flow and small slope gradient.In this paper,an airfoil flip bucket was put forward according to existing research result and practical application aiming to solve the above problems.With the physical model test on spillway tunnel 1^# in the expansion project of Centianhe reservoir as a case study,the effects of different configurations of airfoil flip bucket on the hydraulic characteristics of aeration devices were compared,and the effectiveness of airfoil flip bucket in relieving cavity backwater of aeration devices was also demonstrated,and the basic layout pattern was eventually determined by the physical model test.This study lays a foundation for further research and popularization.

Key words: spillway tunnel, aeration devices, airfoil flip bucket, hydraulic model test, reservoir expansion