摘要
为了探究液滴在通过圆形表面的运动过程中固体表面的润湿性对液滴运动的影响,基于S-C伪势模型的介观格子Boltzmann方法(LBM),课题组对重力场下液滴的运动过程进行了二维数值模拟,并考虑了气-液、液-固间的相互作用力与重力的影响。同时采用MATLAB软件图像处理中的边缘检测技术来提取液滴轮廓线,然后以多项式拟合的方法来获得液滴的接触角。计算结果表明:液滴的整体运动速度会随着接触角的增大而增大,而且都会经历一个相同的速度变化过程,同时在液滴下落的过程中存在一个临界接触角。该研究表明润湿性对液滴运动有显著的影响,其模拟结果对液滴动力学的仿真有一定的参考价值。
In order to study the influence of wettability of solid surface on the motion of droplet passing through a circular surface,a two-dimensional numerical simulation of the motion of droplet passing through a circular surface under gravity field was carried out using the mesoscopic lattice Boltzmann method (LBM) based on the S-C pseudo-potential model.The effects of gas-liquid and liquid-solid interaction forces and gravity were also considered. At the same time,the edge detection technology in image processing of Matlab software was used to extract the contour of droplet,and then the contact angle of droplet was obtained by polynomial fitting method. The calculation results show that the overall velocity of the droplet increases with the increase of contact angle,and it will undergo the same process of velocity change. And there is a critical contact angle in the process of droplet falling. The study show that wettability has a significant influence on droplet motion. The results have certain reference value for the simulation of droplet dynamics.
引文
[1]马学虎,兰忠,王凯,等.舞动的液滴:界面现象与过程调控[J].化工学报,2018,69(1):9.
[2]YOUNG T.An essay on the cohesion of fluids[J].Philosophical Transactions of the Royal Society of London,1805,95:65-87.
[3]张明焜,陈硕,尚智.带凹槽的微通道中液滴运动数值模拟[J].物理学报,2012,61(3):34701.
[4]臧晨强,娄钦.复杂微通道内非混相驱替过程的格子Boltzmann方法[J].物理学报,2017,66(13):154-162.
[5]刘邱祖,寇子明,韩振南,等.基于格子Boltzmann方法的液滴沿固壁铺展动态过程模拟[J].物理学报,2013,62(23):234701.
[6]CHEN Hangyu,ZHANG Jinya,ZHANG Yongxue,et al.Simulation on a gravity-driven dripping of droplet into micro-channels using the lattice Boltzmann method[J].International Journal of Heat&Mass Transfer,2018,126:61-71.
[7]FAKHARI A,RAHIMIAN M H.Simulation of falling droplet by the lattice Boltzmann method[J].Communications in Nonlinear Science&Numerical Simulation,2009,14(7):3046.
[8]石自媛,胡国辉,周哲玮.润湿性梯度驱动液滴运动的格子Boltzmann模拟[J].物理学报,2010,59(4):2595-2600.
[9]褚福强,吴晓敏,陈永根.竖直表面液滴运动的数值模拟[J].工程热物理学报,2017,38(1):143-146.
[10]何雅玲,王勇,李庆.格子Boltzmann方法的理论及应用[M].北京:科学出版社,2009:2-9.
[11]穆罕默德·阿卜杜勒马吉德.格子玻尔兹曼方法[M].北京:电子工业出版社,2015:3.
[12]YUAN Peng,SCHAEFER L.Equations of state in a lattice Boltzmann model[J].Physics of Fluids,2006,18(4):329.
[13]KANG Qinjun,ZHANG Dongxiao,CHEN Shiyi.Displacement of a two-dimensional immiscible droplet in a channel[J].Physics of Fluids,2002,14(9):3203-3214.
[14]MARTYS N S,CHEN Hudong.Simulation of multicomponent fluids in complex three-dimensional geometries by the lattice Boltzmann method[J].Physical Review E,1996,53(1):743-750.