کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
7060153 1458477 2018 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Droplet splashing on thin moving films at high Weber numbers
ترجمه فارسی عنوان
قطره قطرات بر روی فیلم های حرکتی نازک در اعداد بالا وبر
کلمات کلیدی
تاثیر قطره، شماره وایبر بالا، فیلم های نازک فیلمبرداری اندازه گیری ضخامت تجزیه لاملا، شکل حفره،
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی جریان سیال و فرایندهای انتقال
چکیده انگلیسی
The influence of a thin moving film on the splashing of droplets was investigated experimentally at high Weber numbers. This study was conducted using a flywheel experiment fitted with a new film generation system, which allows for the production of thin films with variable mean velocity for different liquids. The thickness was measured using a miniature confocal-chromatic sensor during the rotation of the flywheel. Using shadowgraph techniques, the splashing process was analyzed and the evolution of the crown height and diameter were described. It was also demonstrated that the film velocity and thickness influence the development of the crown geometry. The combination of a high-speed and a high-resolution camera allowed us to observe two different instabilities that accelerate the breakup process, leading to a complete atomization of the crown into secondary droplets. The instabilities observed were: spreading holes and a separation from the crown base. Using the formed holes, we calculated the lamella thickness using two different methods, yielding a constant value of 31 ± 3 µm for all the experiments. We estimated both the time at which the hole instabilities appeared and the time at which the breakup process began. Moreover, it was demonstrated that small bubbles in the lamella are responsible for the hole formation. We also showed that the entire breakup process is delayed by increasing the film flow velocity, regardless of the Weber number.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Multiphase Flow - Volume 101, April 2018, Pages 202-211
نویسندگان
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