摘要
利用耗散粒子动力学(DPD)对简单剪切流条件下液滴的破碎和碰撞分离过程进行了模拟。液滴由多颗简单的DPD粒子构成,液滴与周围流体的不互溶性由提高它们之间的保守力系数获得。通道的上下壁面沿着相反方向运动从而使流体产生简单剪切流动。计算结果表明,在简单剪切流条件下,当界面张力数超过临界界面张力数后,液滴不稳定;液滴将被拉长并破碎成数个较小的稳定的液滴。当两个液滴相互碰撞并分离的现象发生时,两个液滴的质心在速度梯度方向上的距离与整个碰撞过程相关,碰撞之后的δz值比碰撞前的δz大。
The breakup and collision of drops in simple shear flow are investigated using the dissipative particle dynamics (DPD) method.The drop is made up of simple DPD particles,and the immiscible fluids are achieved by increasing the conservative coefficient between the drop and the external fluid. The channel's upper and lower walls are moved in opposite directions to generate the shear flow field. No-slip boundary condition is imposed near the walls,and periodic boundary condition is implemented in the Xand Y directions.The DPD computational results show that the drop is unstable in simple shear flow when the capillary number is larger than the critical value of 0.25.The drop is elongated and sufficiently deformed drop will break up into several smaller stable drops.For separating collision of two drops,the distance between the drop centers along the velocity gradient direction is a function of time,the value of δz after collision is larger than that before collision.
出处
《工程热物理学报》
EI
CAS
CSCD
北大核心
2007年第z1期189-192,共4页
Journal of Engineering Thermophysics
基金
国家自然科学基金资助(No.50576051)
教育部留学回国人员科研启动基金资助
2004上海市优秀青年教师后备人选资助(No.B4725A)
关键词
耗散粒子动力学
液滴
破碎
碰撞
dissipative particle dynamics (DPD)
droplets
breakup
collision
