高速气液两相流液膜卷吸夹带数值模拟研究

NUMERICAL STUDY ON ENTRAINMENT OF LIQUID FILM IN HIGH-SPEED GAS-LIQUID FLOW

本文运用VOF模型对水平管内高速（vg≈272m／s，Ma≈0．8）气液两相二维流场进行了数值模拟，研究了高速气流作用下液膜卷吸夹带机理。结果表明，气液界面产生的扰动波是产生液膜卷吸夹带的主要原因，扰动波吸收波前、后液膜内液体并同时在轴向与径向方向发展，最后伸入气相场中的突起部分受到高速气流剪切力而脱离液膜进入气相。在高速气相场中，同时存在两种不同的夹带现象：大波独立沿轴向和径向发展最终断裂进入气相；小波先合并后再脱离液膜进入气相。卷吸夹带之后的区域出现液膜随机分布的特点。

Entrainment mechanisms of the liquid film in high-speed （vg ≈ 272 m/s, Ma ≈ 0.8） gas-liquid flow in horizontal tube were studied with the VOF model. The results indicated that the entrainment was caused by disturbance waves. The wave absorbs the liquid from the film in the front and behind to develop in both the axial and radial directions, and finally sheared off by the incoming gas. Furthermore, two phenomena were found coexisting in the high-speed gas flow： big waves evolve individually until their crest is sheared off into the gas core, and small ones after them first coalesce and were sheared off by the incoming gas phase. After that the liquid film breaks up into droplets of various sizes and randomly distributed.