Mechanism of hydrodynamic properties affecting sector gate force behavior during dynamic water closure

This study aims to provide a deeper analysis of the mechanical effects induced by turbulent flow characteristics in the gate recess on the sector gate during dynamic water closure. A full-scale three-dimensional geometric model focusing on the gate body was constructed using actual dimensional data. The third-generation Liutex-Omega vortex identification criterion was employed to clarify the evolution of vortex structures and quantify vortex intensity. The temporal variation of forces acting on the nose and skin plate was systematically analyzed through shear effects and stagnation pressure characteristics, revealing the interaction mechanisms between the gate and the flow during closure. The results demonstrate that the absolute vortex intensity near the central nose and side noses alternates in dominance, with two instances of equal intensity. The vortex evolution within the gate recess progresses through eight distinct stages. During the primary vortex attenuation and dissipation stage, transient peak operating forces arise due to a short moment arm, strong shear forces, and a resultant force near the side nose that tends to open the gate. The force peak occurs at gate openings ranging from 0.20 to 0.25, and exhibits an exponential relationship with the chamber flow velocity. This study offers novel insights into the force behavior characterization of sector gates under hydrodynamic operating conditions.