Author(s): Xinlei Guo; Kailin Yang; Yongxin Guo; Hui Fu; Tao Wang
Keywords: T-junction; Chamber; ∴- type diversion walls; Flow characteristics
Abstract: The Wangqingtuo junction chamber, a T type hydraulic structure with a lateral inflow or outflow at 90°angle, is a hinge of Tianjin main line of South-to-North water diversion project joining Wangqingtuo reservoir. The paper aims to investigate the hydraulic performance of the junction chamber and optimize the preliminary design. Different depth measurements were made using a point gauge while velocity measurements were taken using an acoustic doppler velocimeter over a grid defined throughout the junction region in experimental test. The velocity distribution was calculated from a time series of velocities that was recorded at each location. Based on the flow characteristics and results, the water diversion and vortex precaution device of ∴- type diversion walls was developed. The main characters of this new device is that three diversion walls are parallel arranged with one in the middle and the other two in the extended line of the separation walls in the junction chamber. It was found that the velocity downstream was well distributed and the vertical-axis vortex in front of the outlet gate was prevented by adjusting the relative position of the three rows of diversion wall. Such new device with simply structure and easy construction and low investment can be extended to other similar lateral inflow or outflow projects.