کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4951094 1364325 2016 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Bounce regime of droplet collisions: A molecular dynamics study
ترجمه فارسی عنوان
ریکاوری رد شدن از برخورد قطرات: مطالعه دینامیک مولکولی
کلمات کلیدی
جریان چند مرحلهای، برخورد دو قطبی قطره، نانومقیاس، دینامیک مولکولی، قطره گزاف گویی،
موضوعات مرتبط
مهندسی و علوم پایه مهندسی کامپیوتر نظریه محاسباتی و ریاضیات
چکیده انگلیسی


- Reproduced the binary collision bounce regime in nanoscale by MD simulation.
- Extended the gas film theory for bounce regime.
- Considered impact velocity and ambient pressure as two key parameters affecting the appearance of the bounce regime.
- Discussed the differences between nanoscale and microscale droplet dynamics.
- Completed the regime map of nanoscale binary droplet collisions.

Droplet collisions have complex dynamics, which can lead to many different regimes of outcomes. The head-on collision and bounce back regime has been observed in previous experiments but numerical simulations using macro- or mesoscale approaches have difficulties reproducing the phenomena, because the interfacial regions are not well resolved. Previous molecular dynamics (MD) simulations have not reproduced the bounce regime either but have reported the coalescence and/or shattering regimes. To scrutinize the dynamics and mechanisms of binary collisions especially the interfacial regions, head-on collision processes of two identical nano-droplets with various impact velocities both in vacuum and in an ambient of nitrogen gas are investigated by MD simulations. With the right combination of the impact velocity and ambient pressure, the head-on collision and bounce back phenomenon is successfully reproduced. The bounce phenomena are mainly attributed to the “cushion effect” of the in-between nitrogen molecules and evaporated water molecules from the two nano-droplets. The analysis has verified and also extended the current gas film theory for the bounce regime through including the effects of evaporated water molecules (vapour). Some similarities and some dissimilarities between nanoscale and macro-/meso-/microscale droplet collisions have been observed. The study provides unprecedented insight into the interfacial regions between two colliding droplets.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Computational Science - Volume 17, Part 2, November 2016, Pages 457-462
نویسندگان
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