مطالعه عددی تأثیر میدان های مغناطیسی غیر یکنواخت در انتقال حرارت و پیشروی جبهه انجماد و ذوب در یک محفظه بسته

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشکده مهندسی شیمی و نفت، دانشگاه تبریز، تبریز، ایران

2 دانشکده مهندسی مکانیک، دانشگاه شهید مدنی آذربایجان، تبریز، ایران

چکیده

اخیرا سیستم های جدید ذخیره سازی انرژی با استفاده از مواد تغییر فاز دهنده مورد توجه زیادی قرار گرفته‌اند، زیرا این مواد در هنگام تغیر فاز، می توانند انرژی را در دمای ثابت جذب و آزاد کنند. با توجه به این ویژگی، آنها به طور گستردهای در سیستم های انرژی استفاده می شود. در این مطالعه، تأثیر اعمال میدان مغناطیسی غیر یکنواخت با گرادیان‌های مثبت و منفی بر روی انتقال حرارت و پیشروی جبهه انجماد و ذوب نانوسیال مغناطیس شونده فاقد هدایت الکتریکی بعنوان یک ماده تغییر فاز دهنده در یک محفظه چهارگوش در حضور میدان‌های مغناطیسی مختلف به‌صورت عددی با استفاده از مدل تک فازی همگن و روش حجم محدود، مورد بررسی قرار گرفته است. در کار حاضر برای تحلیل فرآیند انجماد و ذوب مواد تغییر فاز دهنده بهبود یافته با نانوذرات (که در مطالعه حاضر از نانوذرات اکسید آهن استفاده شده است،). از روش آنتالپی- تخلخل استفاده شده است. با توجه به نتایج بدست آمده، نانوذرات و اعمال میدان مغناطیسی باعث سرعت بخشیدن به فرآیندهای ذوب و انجماد می‌شود. میدان مغناطیسی با گرادیان منفی در جهت محور عمودی، در هر دو حالت انجماد و ذوب بیشترین تأثیر را در پیشروی سریع جبهه انجماد و ذوب و در نتیجه کوتاه‌تر شدن زمان این فرآیند دارد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Numerical Investigation of Non-Uniform Magnetic Fields Effects on Heat Transfer and Development of Melting- Solidification Processes in an Enclosure

نویسندگان [English]

  • M. Mohammadpourfard 1
  • M. Rostami Dibavar 2
1 Faculty of Chemical and Petroleum Engineering, University of Tabriz, Tabriz, Iran
2 Department of Mechanical Engineering, Azarbaijan Shahid Madani University, Tabriz, Iran
چکیده [English]

Developing new energy storage systems using Phase Change Materials (PCMs) have been recently attracted considerable interest, since these materials during phase transition, could absorb and release energy at a constant temperature. Due to this feature, they are widely used in energy systems. In this investigation, the effects of applying nonuniform magnetic field with negative and positive gradients on the heat transfer and also on the development of solidification and melting processes of a non-electrical conductive magnetic nano-fluid as a PCM in an enclosure in the presence of different magnetic fields have been studied numerically using single phase homogenous model and control volume technique. In the present study, the enthalpy-porosity method has been used for analyzing the solidification and melting process of phase change materials enhanced with nanoparticles (in this study Fe3O4 nanoparticles have been used). The obtained results show using nanoparticles and applying magnetic fields increase the development of solidification and melting processes. Due to heat transfer through vertical walls, the effect of the magnetic field with positive and negative gradients only in the y-axis direction has been investigated. Since the magnetic field is applied only to the mushy zone, a magnetic field with a negative gradient in the vertical axis direction will have the greatest effect on the progression of the solidification and melting process so that the time of these processes will be decreased.

کلیدواژه‌ها [English]

  • Melting and Solidification Development
  • Single Phase Homogenous Model
  • Enthalpy-Porosity Method
  • Non-uniform Magnetic Field
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