自由射流涡环的形成演化及空化现象

Formation and Evolution of Free Jet Vortex Ring and Cavitation Phenomenon

自由射流在淹没状态下产生涡环是流体力学中的常见现象,在高雷诺数时涡环的涡核区域会产生空化现象。通过大涡模拟方法进行数值模拟,研究了两种典型雷诺数下涡环的形成与演化过程,结果表明:雷诺数Re=3000时,涡核区域没有空化现象产生,此时涡环为纯液相涡环;雷诺数Re=160000时,在涡环的涡核区域产生了空化现象,此时涡环为气液两相涡环;通过分析流场的压力分布和蒸汽体积分数分布,找到了涡环发生空化现象的空化压力。

Free jet generating vortex rings in the submerged regime is a common phenomenon in hydrodynamics,and cavitation occurs in the vortex core region of the vortex ring at high Reynolds number.The Large eddy simulation method is used for numerical simulation,and the formation and evolution process of vortex rings under two typical Reynolds number are studied.The results show that at Reynolds number Re=3000,the vortex ring is pure liquid phase vortex ring;at Reynolds number Re=160000,the cavitation phenomenon occurs,and the vortex ring is gas-liquid two-phase vortex ring;Furthermore,the vortex volume distribution in the flow field is analyzed to study the formation and evolution process of the vortex ring by analyzing the pressure distribution of the flow field.