摘要
对水洗流场中液滴的界面膜剪切破裂机理进行了分析和初步探讨,认为水洗流场中控制着液滴产生变形和剪切破裂的无因次群有3个,其中韦伯数群控制着液滴的破裂;在紊流状态的水洗流场中,导致液滴破碎的水力学因素可归结为由于时均的速度梯度而产生的粘性剪切力和由于紊流而产生的瞬时剪切力和局部压力波动等;当流场动压力所提供的流场能量较小时,主要以粘性剪切力为主控制着液滴的变形;当连续相提供的能量达到使液滴破裂的能量时,瞬时剪切力和局部压力波动将控制着液滴的破碎。当液滴振动的动能Ek≥液滴的表面自由能Es,液滴发生破裂。
The mechanism of droplet interfacial film breaking and shearing in water-washing flow field is analyzed and discussed initially. It is considered that there are 3 dimensionless groups in the flow field, they control the distortion and shear fracture, Weber numbers control the droplet rupture. In the turbulent water-washing field, the hydraulic factors resulting in the droplet rupture are induced by viscous shear stress of even velocity gradient, instantaneous shear stress caused by turbulent flow and local pressure fluctuation. When the energy provided by pressure in the flow field is less, viscous shear force is dominated to control the droplet distortion, when the energy provided by continuous phase reaches the energy for droplet rupture, its rupture is controlled by the instantaneous shear stress and local pressure fluctuation, the droplet rupture takes place when the droplet vibrational kinetic energy EK≥ES, its surface free energy.
出处
《石油机械》
北大核心
2006年第6期28-31,共4页
China Petroleum Machinery
基金
中国石化集团公司科研攻关项目(2003-108)"油气水砂四相分离技术研究"中的部分内容。
关键词
油水分离
水洗流场
液滴剪切
破裂
oil-water separation, water-washing flow field, droplet shear rupture
