مطالعه عددی رژیم‌های مختلف شعله در اسپری جریان متقابل آرام

هواسی, مراد; امی, فتح اله; چیتگرها, فاطمه

doi:10.22034/jfnc.2021.230030.1217

مطالعه عددی رژیم‌های مختلف شعله در اسپری جریان متقابل آرام

نوع مقاله : مقاله پژوهشی

نویسندگان

¹ دانشگاه تربیت مدرس

² رئیس پژوهشگاه هوافضای وزارت علوم، تحقیقات و فناوری

10.22034/jfnc.2021.230030.1217

چکیده

شبیه‌سازی عددی دوبعدی شعله اسپری تشکیل‌شده در یک پیکربندی جریان متقابل آرام، به‌منظور بررسی رژیم‌های شعله و تأثیر آن بر تغییرات گونه‌ها و رادیکال‌های مهم، انجام ‌شده است. از اتانول به‌عنوان یک سوخت اسپری مایع استفاده شده و مکانیسم اسکلتی اتانول/هوا با ۴۰ گونه و ۱۸۰ واکنش مقدماتی برای واکنش‌های احتراق به کار گرفته شده است. قطرات سوخت با قطر یکسان و به‌صورت تصادفی با استفاده از یک کد UDF در ورودی هوا تزریق می‌شوند و حرکت قطرات براساس دیدگاه لاگرانژی محاسبه شده است. با توجه به نتایج در نسبت های هم ارزی بالا، نرخ های کرنش بالا و قطرهای بزرگ قطرات، رژیم غالب شعله به‌صورت غیرپیش‌آمیخته است. همچنین، در نواحی مرکز شعله، به دلیل صفرشدن مقدار کسر جرمی اکسیدکننده و کاهش مقدار کسر جرمی رادیکال OH در این ناحیه، واکنش‌های احتراقی فرونشانده شده و همچنین مقدار عدد شاخص شعله صفر می‌شود که نشان‌دهندۀ احتراق گروه داخلی قطرات در این ناحیه است.

کلیدواژه‌ها

موضوعات

احتراق

عنوان مقاله [English]

Numerical study of different flame regimes in the laminar counterflow spray

نویسندگان [English]

morad havasi ¹
fathollah ommi ²
Fatemeh chitgarha ¹

¹ Tarbiat Modares University

² Head of the Aerospace Research Institute of the Ministry of Science, Research and Technology

چکیده [English]

The two-dimensional numerical simulation of the spray flame formed in a laminar counterflow configuration has been performed to investigate flame regimes and its effect on changes in important species and radicals. Ethanol is used as a liquid spray fuel and the skeletal mechanism of ethanol/air with 40 species and 180 preliminary reactions is used for combustion reactions. The Sauter mean diameter of fuel droplets and randomly injected into the air inlet are considered using a UDF code, and the motion of the droplets is calculated using the Lagrangian approach. The results show that the predominant flame regime is Non-Premixed in the high equivalences ratio, high strain rates and large droplet diameters. Also, the combustion reactions are suppressed in the center areas of the flame, due to the reduction of the oxidant fraction and the OH mass fraction, and the flame index is zero, which indicates the internal group of droplets in this area.

کلیدواژه‌ها [English]

Configuration of Counter-flow
Spray Combustion
Laminar Flow
premixed
non-premixed

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