@Article{CiCP-10-453, author = {}, title = {Numerical Study of Surfactant-Laden Drop-Drop Interactions}, journal = {Communications in Computational Physics}, year = {2011}, volume = {10}, number = {2}, pages = {453--473}, abstract = {

In this paper, we numerically investigate the effects of surfactant on drop-drop interactions in a 2D shear flow using a coupled level-set and immersed interface approach proposed in (Xu et al., J. Comput. Phys., 212 (2006), 590–616). We find that surfactant plays a critical and nontrivial role in drop-drop interactions. In particular, we find that the minimum distance between the drops is a non-monotone function of the surfactant coverage and Capillary number. This non-monotonic behavior, which does not occur for clean drops, is found to be due to the presence of Marangoni forces along the drop interfaces. This suggests that there are non-monotonic conditions for coalescence of surfactant-laden drops, as observed in recent experiments of Leal and co-workers. Although our study is two-dimensional, we believe that drop-drop interactions in three-dimensional flows should be qualitatively similar as the Maragoni forces in the near contact region in 3D should have a similar effect.

}, issn = {1991-7120}, doi = {https://doi.org/10.4208/cicp.090310.020610a}, url = {http://global-sci.org/intro/article_detail/cicp/7450.html} }