بررسی CFD انتقال حرارت جابجایی اجباری نانوسیالات در یک کانال حاوی ذرات کروی شکل

نوع مقاله: پژوهشی

نویسندگان

دانشگاه صنعتی قوچان

چکیده

در این پژوهش انتقال حرارت نانوسیالات از سطح کروی به کمک دینامیک سیالات محاسباتی مورد بررسی قرار گرفته است.در شبیه سازی­ها از مدل­های مختلف جریان جهت دست­یابی به نتایج بهینه استفاده ­شده است. نتایج حاصل از شبیه­سازی با نتایج حاصل از روابط نیمه تجربی معتبر مورد مقایسه قرار گرفت و در نهایت مدل RNG k-&epsilon جهت شبیه سازی برگزیده شد. نتایج نشان می­دهد کهاستفاده از نانوسیالات موجب بهبود انتقال حرارت در کانال پرشده می­شود.با5 برابر شدن غلظت نانوذرات انتقال حرارت 6/2 برابر بهبود می­یابد. در جریان­های با رینولدز کم (2/11 Re=) استفادهازنانوسیالاتحاوینانوذرات نقره حداکثر 8/2 برابر موجببهبود انتقال حرارت نسبت به نانوسیالات حاوی نانوذرات اکسید آلومینیوم می­شود. با افزایش رینولدز از میزان تأثیر نانوسیالات بر میزان انتقال حرارت کاسته می­شود به طوریکه در 11190= Re اثر هر سه نوع نانوذرات نقره، اکسید آلومینیوم و مس بر درصد بهبودی یکسان است.

کلیدواژه‌ها


عنوان مقاله [English]

CFD Investigation on Nanofluids Convective Heat Transfer in a Duct Containing Spherical Surfaces

نویسندگان [English]

  • R G
  • Hossein Beiki
university
چکیده [English]

In this paper, heat transfer rate from these surfaces were studied by computational fluid dynamics. The effect of nanoparticles concentrations and kinds on the rate of heat transfer were investigated numerically. Different models were used in order to access optimum results in simulations. The results of these simulations were compared with the well-known empirical relationships and showed a good adaptation.Finally, the RNG k-&epsilon model was chosen to simulate the heat transfer from spherical surface in the turbulent regimes. The results showed that with 5 times increasing in nanoparticles concentration, heat transfer rate increased 2.6 times. At low Reynolds number (Re=11.2), the enhancement of heat transfer rate in Ag nanofluids was 2.8 fold greater than that in Al2O3 nanofluids.Nanoparticles effects were negligible at high Reynolds number so that at Re=11190 heat transfer at three different kinds of nanofluids, which were contained Ag, Al2O3 and Cu nanoparticles,was equal.

کلیدواژه‌ها [English]

  • Heat transfer
  • spherical surface
  • CFD
  • Nanofluid
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