Investigation on Turbulent Nanofluid Flow in Helical Tube in Tube Heat Exchangers
- سال انتشار: 1398
- محل انتشار: مجله تحقیقات انتقال حرارت و توده، دوره: 6، شماره: 1
- کد COI اختصاصی: JR_JHMTR-6-1_004
- زبان مقاله: انگلیسی
- تعداد مشاهده: 119
نویسندگان
University of Isfahan
University of Isfahan
University of Isfahan
University of Isfahan
چکیده
In this study, the thermal characteristics of turbulent nanofluid flow in a helical tube in the tube heat exchanger (HTTHE) were assessed numerically through computational fluid dynamics (CFD) simulation. The findings of both the turbulent models: realizable k-epsion (k-ε) and re-normalisation group (RNG) k-epsilon were compared. The temperature distribution contours show that realizable and RNG k-ε models, together with the swirl dominated flow are of more uniform temperature distributions. The proper prediction of two layer theory leads to having a uniform temperature distribution and proper dimensionless wall distance (Y+). The turbulent flow and heat transfer of two nanofluids (SiO۲, Al۲O۳) and base fluid with respect to swirl dominated flow was simulated through the RNG model. The effects of the concentration of nanoparticles on heat transfer characteristics in HTTHE and two turbulent models were analyzed in a comprehensive manner. It is concluded that up to ۱% concentration of SiO۲ and ۱% concentration of Al۲O۳, similar heat transfer characteristics are observed. Comparison between the CFD results with the predicted values for friction factor coefficient (f) and Nusselt number (Nu) calculated through experimental correlations indicate the maximum errors of ۶.۵۶% and ۰.۲۷%, respectively.کلیدواژه ها
Nanofluids coiled double tubes heat exchanger, friction factor, heat transfer coefficientاطلاعات بیشتر در مورد COI
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