Abstract: Hydraulic model test is an important means to verify the rationality of water building design.In this study, physical model test is carried out to research the water diversion tunnel of Yellow River Diversion Project in the Middle of Shanxi Province based on fluid theory and hydraulic model theory. Flow capacity of the main tunnel and flow distribution between west branch tunnel and east branch tunnel with different gate openings are studied; the relationships of gate opening and closing rate against water level in front of gate are obtained. Results demonstrate that the design flow discharge and discharge ratio can be achieved in the presence of east gate opening at 0.60 m and west gate opening at 0.56 m. Moreover, gate opening and closing rate is negatively correlated with upstream water level. The results are of theoretical significance for researching the flow capacity of non-pressurized water delivery tunnel, and provide reference for gate control system.

Key words: water delivery tunnel of long distance, flow diversion, hydraulic model test, flow capacity, gate opening