干船坞气控式卧倒门起浮过程流动分析

Flow Structure around Pneumatic Flap Gate in Dry Dock during Floating Process

修造船坞中卧倒门起卧时的稳定性受水流动力的影响较大。基于RANS方程,利用RNG k-ε双方程紊流模型进行封闭,采用VOF方法跟踪自由水面,对干船坞气控式卧倒门的起浮过程进行了动网格模拟计算。综合考虑三种水位下坞门起卧时的流动特性,结合模型试验数据分析流场和紊动动能随坞门起浮时的变化,为坞门的动力特性分析和坞门设计提供依据。计算结果表明,伴随着顺时针和逆时针涡动结构的快速发展,紊动动能主要集中于铰座、前面板的上端和后门角三处附近水域。随着水位抬升,此三处的紊动动能亦呈现增大趋势,涡动的变化范围加大,尤其是水下运行阶段和关闭阶段,铰座处水域的门坑将受到最强烈的冲击。

Stability of pneumatic flap gate in floating and submerging state in a built dockyard is greatly influenced by hydrodynamic forces acting on the gate. Based on RANS equations combined with RNG k-ε turbulence closure and by using VOF method for tracking free surface, flow characteristics of dock gate are investigated in floating or flapping state and under three water levels. After comparing the data of model test with that of calculation, the flow structure around pneumatic flap gates is simulated. The results indicate that turbulent kinetic energy focuses mainly on the nearby area of hinged support, top of the front panel and the back gate angle, along with the quick development of clockwise and counterclockwise vortexes. With the elevation of water level, not only increases the turbulent kinetic .energy at the three places, but also the range of eddy expands greatly, especially at underwater operation stage and closing stage. That will produce strong scouring effect on gate pit near hinged support.