شبیه‌سازی عددی فرایند تشکیل قطره درون میکروکانال تی- شکل دوبعدی با استفاده از روش تنظیم سطح

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشجوی کارشناسی ارشد، دانشکده مهندسی مکانیک، دانشگاه صنعتی ارومیه، ارومیه، ایران

2 استادیار، دانشکده مهندسی مکانیک، دانشگاه صنعتی ارومیه، ارومیه، ایران

3 دانشیار، دانشکده مهندسی مکانیک، دانشگاه صنعتی ارومیه، ارومیه، ایران

چکیده

در این تحقیق یک شبیه‌سازی عددی بصورت دوبعدی با استفاده از روش تنظیم سطح دوفازی برای بررسی تاثیر نرخ جریان ورودی فاز پیوسته در فرایند تولید میکروقطره انجام شده است. تحلیل فرایند تشکیل میکروقطرات در یک میکروکانال تی- شکل برای جریان دوفازی مایع/مایع امتزاج‌ناپذیر صورت گرفته است. معادلات حاکم بر میدان جریان توسط روش المان محدود گسسته‌سازی و حل شده‌اند. نتایج عددی بدست‌آمده با داده‌های تجربی موجود در ادبیات فن اعتباردهی شده است، که نشان‌دهنده مطابقت قابل قبولی می‌باشد. نتایج نشان می‌دهد که نرخ جریان ورودی فاز پیوسته تاثیر بسزایی بر روی اندازه قطرات تولید شده دارد. مطالعات انجام‌شده حاکی از آن است که نمودار فشار در نقطه تلاقی دو کانال عمودی و افقی تعداد قطرات تشکیل شده و مراحل سه‌گانه‌ی تشکیل قطره را نشان می‌دهد. همچنین، بررسی‌ها بیان می‌کنند که اختلاف فشار جلو و پشت قطره و نیروی برشی ناشی از ویسکوزیته دو نیروی موثر در تشکیل قطره می‌باشند که در این بین تاثیر نیروی ناشی از اختلاف فشار دو سمت قطره بیشتر است. نهایتا این نتیجه حاصل می‌شود که با افزایش مقدار دبی ورودی فاز پیوسته نیروی لازم جهت غلبه بر کشش سطحی نیز افزایش یافته و قطرات بیشتری با اندازه کوچکتر در مدت زمان کمتری تولید می‌شوند.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Numerical simulation of droplet formation in a T-shape microchannel using two-phase level-set method

نویسندگان [English]

  • Mohammad Raad 1
  • Sajadollah Rezazadeh 2
  • Abdolrahman Dadvand 3
1 Master of science student, Faculty of mechanical engineering, Urmia University of Technology, Urmia, Iran
2 Faculty of mechanical engineering, Urmia University of Technology, Urmia, Iran
3 Associated Professor, Faculty of mechanical engineering, Urmia University of Technology, Urmia, Iran
چکیده [English]

In this study, a two-dimensional numerical simulation using the two-phase level set method has been carried out to investigate the influence of continuous phase entrance flow rate on the microdroplets generation process. Analysis of the breakup process of microdroplets in immiscible liquid/liquid two-phase flow in T-junction microchannel was predicted. Governing equations on the flow field have been discretized and solved using the finite element method. Obtained numerical results were validated by comparing the experimental data reported in the literature which show acceptable agreement. Results show that the continuous phase entrance flow rate has a major effect on the size of generated droplets. Studies have shown that the pressure diagram of the junction point can reflect the number of formed droplets and the triple stages of droplet formation. Also, examinations of the pressure and velocity gradient inside the main channel show that the pressure difference of the droplet’s tip and rear and shear force caused by viscosity dominates the droplet formation which the pressure difference between two sides of droplet is more effective. Finally, it could be concluded that by increasing the inlet flow rate of the continuous phase, the needed force for overcoming the surface tension increases and more droplets with small sizes are generated in a short time.

کلیدواژه‌ها [English]

  • Microfluidic technology
  • two-phase flow
  • droplet formation
  • Level set Method
  • T-shape microchannel
 
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