شبیه سازی عددی میدان جریان و انتقال حرارت درون کانال با ابعاد مختلف موانع دوکی در حضور سیال غیرنیوتنی مدل توانی

نوع مقاله : مقاله مکانیک

نویسندگان

1 دانشگاه ایوانکی

2 کارشناس ارشد، دانشکده مهندسی مکانیک، دانشگاه ایوان کی سمنان

چکیده

در این مقاله به تحلیل میدان جریان و انتقال حرارت جابجایی اجباری سیالات غیرنیوتنی درون کانال با موانع دوکی شکل پرداخته شده است. در ابتدا پس از بررسی معادلات حاکم و شرایط مرزی حاکم بر مسئله، استقلال حل از تعداد شبکه صورت گرفته است. سپس نتایج تحقیق حاضر در دو حالت برای سیالات نیوتنی و غیرنیوتنی با مطالعات مشابه پیشین صحت‌سنجی شده‌ است. اثرات پارامترهای مختلفی مانند اثر آرایش موانع دوکی، اثر قطر موانع و اثر دنباله موانع مورد بررسی قرار گرفته است. همچنین اثر شاخص‌های توانی مختلف سیال غیرنیوتنی و تاثیر آن بر ضریب درگ و عدد ناسلت مورد بررسی قرار داده شده است. با بررسی نتایج مشخص شد که به ازای کلیه پارامترهای مورد بررسی، آرایش جابجا شده موانع دوکی نسبت به حالت آرایش منظم، میزان انتقال حرارت بیشتری داشته است. نتایج این تحقیق نشان داد که با افزایش قطر و دنباله موانع، میزان انتقال حرارت از موانع کاهش می‌یابد. همچنین با افزایش قطر پیشانی موانع، ضریب درگ فشاری و اصطکاکی افزایش پیدا می‌کند. در انتها با بررسی رفتار سیال غیرنیوتنی مدل توانی مشخص شد که با افزایش شاخص توانی عدد ناسلت کاهش پیدا یافته و برای سیالات غیرنیوتنی باریک شونده (n<1) میزان افت‌های اصطکاکی و فشاری کمتری به دست آمده است.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Numerical simulation of the flow field and heat transfer inside the channel with different dimensions of spindle obstacles in the presence of power-law non-Newtonian fluids

نویسندگان [English]

  • Danesh Mirzaei 1
  • Mostafa Sayah Badkhor 2
  • Mohammad Reza Rezaie 2
1 Ivanki University
2 Department of Mechanical Engineering, University of Eyvanekey, Semnan, Iran
چکیده [English]

In this article, the analysis of the flow field and forced convection heat transfer of non-Newtonian fluids inside the channel with spindle-shaped obstacles is discussed. At first, after checking the governing equations and the boundary conditions of the problem, the grid independency has been evaluated. Then, the results of the present study have been validated for two cases of the Newtonian and non-Newtonian fluids with previous similar works. The effects of various parameters such as the effect of the arrangement of spindle obstacles, the effect of the obstacles diameter and the effect of the obstacles length have been investigated. Also, the effect of different power indexes of non-Newtonian fluid and its effect on drag coefficient and Nusselt number have been investigated. By examining the results, it was found that for all the mentioned parameters, the staggered arrangement of the spindle obstacles had a higher heat transfer rate than the ordered arrangement. The results of this research revealed that with the increase in the diameter and length of the obstacles, the amount of heat transfer from the obstacles decreases. Also, by increasing the diameter of obstacles, the pressure and friction drag coefficients increases. Finally, by examining the behavior of the non-Newtonian fluid of the power-law model, it was found that with the increase of the power index, the Nusselt number decreased and for shear thinning non-Newtonian fluids (n<1) less friction and pressure drops were obtained.

کلیدواژه‌ها [English]

  • Numerical simulation
  • Spindle barrier
  • Dimensions of the spindle obstacle
  • Non-newtonian fluid
  • power index
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