Based on RNGκ-εtwo-equation model, the volume of fraction method for free surface calculation and dynamic mesh model,the steel arch-gate closing process was simulated successfully at middle-gate chamber with abrupt lateral expansion and bottom offset aerator outlet in spillway tunnel.The variation regular of hydraulic characteristics including flow pattern,cavity length and wall pressure were mainly researched in the Ogee curve section of spillway tunnel assisted by experiment method.The results showed that the worse flow regimes including bottom cavity reflux and lateral wall water wing would gradually weaken and disappear finally.The cavity length increases linearly.If the gate opening is large than 1/2,there are higher pressure peak value and pressure gradient in impacted scope.However,if the gate opening is less than 1/2,the pressure peak would gradually decrease and disappear with the arch-gate closing.Besides,the computational results agreed well with experimental results to verify the validity of numerical method.
