شبیه سازی عددی پدیده جابجایی اجباری گازهای تابشی داخل یک کانال همراه با جدایش

دهقانی راینی, عباس; گنجعلی خان نسب, سید عبدالرضا

شبیه سازی عددی پدیده جابجایی اجباری گازهای تابشی داخل یک کانال همراه با جدایش

نویسندگان

دانشکده فنی و مهندسی دانشگاه آزاد اسلامی واحد کرمان

چکیده

در مطالعه حاضر آنالیز عددی و دو بعدی جریان جابه‌جایی اجباری آرام سیال بر روی دو پله‌ شیب دار با انقباض در داخل کانال‌های با مقطع مستطیلی و با در نظر گرفتن اثرات تابشی گاز مورد بررسی قرار گرفته است. دلیل انتخاب این هندسه کاربرد بسیار زیاد آنها در صنعت و به خصوص استفاده از آنها در اتصال کانال هایی با سطح مقطع متفاوت بهم دیگر می باشد. سیال عامل، همانند یک محیط خاکستری در جذب، صدور و پخش تشعشع شرکت می کند. جهت به‌دست آوردن میدان‌های سرعت و دما معادلات مومنتوم و انرژی به صورت عددی حل می‌شوند. فرم جداسازی شده‌ معادلات حاکم، توسط روش حجم محدود به دست آمده و با به کار بردن الگوریتم سیمپل حل می‌شوند. برای شبیه‌سازی جریان روی پله داخل کانال، از روش مسدود شده در سیستم مختصات کارتزین دو بعدی استفاده شده است. از آنجایی که گاز به عنوان یک محیط شرکت کننده در انتقال حرارت تشعشعی نقش دارد، تمام مکانیزم‌های انتقال حرارت که شامل جابه‌جایی، هدایت و تشعشع بوده به طور هم زمان در جریان گاز درنظر گرفته می‌شوند.

کلیدواژه‌ها

20.1001.1.23223278.1396.6.1.5.2

عنوان مقاله [English]

Numerical Simulation of Forced Convection Duct Flow of a Radiating Gas with Separation

نویسندگان [English]

abbas dehghani rayni
abdolreza ganjali nasab

kerman

چکیده [English]

In this paper, a numerical study of a 2-D combined convection-radiation heat transfer in a horizontal rectangular duct with two sudden contractions is presented. Contractions in duct are created by two inclined forward facing steps. To simulate the incline surfaces of the FFS, the blocked- off method was employed for both fluid mechanic and radiation problems. The fluid was treated as a gray, absorbing, emitting and scattering medium. To solve the governing equations, the 2-D Cartesian coordinate system was used. These equations were solved numerically, using the CFD techniques and SIMPLE algorithm. For computation of radiative term in energy equation, the radiative transfer equation (RTE) was solved numerically by discrete ordinates method (DOM) to find the divergence of radiative heat flux distribution. The effects of optical thickness, radiation-conduction parameter and albedo coefficient on heat transfer behavior of the system were carried out. Comparison of numerical results with available credential data shows good consistency.

کلیدواژه‌ها [English]

Sudden Contraction
Forward Facing Step
Radiation Heat Transfer
Blocked - off Method
Discrete Ordinate Method

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