نوع مقاله : مقالة‌ تحقیقی‌ (پژوهشی‌)

نویسندگان

1 گروه هوافضا، دانشکده مهندسی مکانیک، دانشگاه تربیت مدرس، تهران، ایران

2 دانشکده مهندسی مکانیک، دانشگاه تربیت مدرس، تهران، ایران

چکیده

 در این پژوهش، مطالعه عددی بر روی مشخصات افشانه یک انژکتور دوپایه ترکیب داخلی دو فاز به کمک روش لاگرانژی در فضای گسسته صورت گرفته­ است. برای بررسی انژکتور، معادلات اویلری برای جریان دوفازی داخل انژکتور و معادلات لاگرانژی برای مدلسازی جریان دوفازی خارج انژکتور به کار گرفته­شده و از روش توربولانسیK-ɛ برای تعیین انرژی توربولانس استفاده شده ­است. در این پژوهش آب به جای سوخت و نیتروژن به عنوان فاز گازی انتخاب شده و با تنظیم نسبت دبی جرمی نیتروژن به آب  معادل32/0 و متعاقب آن بدست آمدن زاویه پاشش 26درجه، مشخصات قطرات بررسی شده و با نتایج روش ماکزیمم آنتروپی مورد مقایسه قرار گرفته ­است. سپس مشخصات ذرات با تغییر مقادیر ورودی فازهای مایع و گازی بررسی شده و بر اساس آن امکان بهینه­ سازی انژکتور برای شرایط راندمان حداکثری از منظر قطر قطرات، سرعت قطرات و میزان نفوذ با مدلسازی عددی و با نیاز حداقلی به نتایج تجربی فراهم شده است.

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

Numerical study on spray characteristic of double phases internal mix atomizer with Lagrangian approach

نویسندگان [English]

  • Alireza Mohammadi 1
  • Fathollah Ommi 2

1 Department, Mechanical Engineering, Tarbiat Modares University, Tehran. IRAN

2 Department of Mechanical Engineering, Tarbiat Modares University, Tehran, IRAN

چکیده [English]

This paper presents numerical study on spray characteristics and droplet distribution by using Lagrangian method in the discrete phase model of CFD. A two-fluid Eulerian method and Lagrangian approach is selected for modeling two phases turbulence flow in mixing chamber and atomization at outlet of nozzle while turbulence has been modeled by K-ɛ. In this study, water has been used instead of fuel and Nitrogen instead of atomization gas or oxidizer, while their ratio has been considered 0.32 to provide 26 degrees cone angle and this way, droplet‘s characteristic has been studied and compared with maximum entropy methods. Then droplet‘s diameter has been investigated by changing liquid and gas phase flow rateand based on that, we can optimize atomizer ‘s working condition with maximum efficiency with respect to its cone angle, droplet ‘s diameter and velocity and level of penetration by minimum need of experimental tests.

کلیدواژه‌ها [English]

  • Spray
  • Internal mix atomizer
  • lagrangian method
  • Turbulence
  • Liquid break up
  • droplet dimension and velocity
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