کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4995470 1458710 2017 13 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Solid-liquid phase change around a tube with periodic heating and cooling: Scale analysis, numerical simulations and correlations
ترجمه فارسی عنوان
فاز سیال جامد در اطراف یک لوله با گرمایش و خنک سازی دوره ای: تجزیه و تحلیل مقیاس، شبیه سازی عددی و همبستگی
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی جریان سیال و فرایندهای انتقال
چکیده انگلیسی
This work studies solid-liquid phase change around a tube in a latent energy storage unit with cyclic thermal loading and unloading (i.e. alternate heating and cooling), while taking into account natural convection. A scale analysis is used to predict the tube surface temperature and the extent of the molten and solidified zones around the tube as a function of the main governing dimensionless parameters (the Stefan and Rayleigh numbers, and the period of the imposed sinusoidal heat transfer rate). A numerical model is then developed to simulate the process under a periodic regime and verify the scale analysis. Temperature, liquid fraction and flow fields are reported as a function of the main governing parameters. A frequency analysis is also proposed to develop a better understanding of how the system behaves. It is shown that the dimensionless group Pr/(τ∼Ra1/5Ste) allows to determine the importance of natural convection in the system. Results indicate that the size of the zone affected by the alternate heating and cooling increases when the period or the Stefan number increased, but was less sensitive to the Rayleigh number. Correlations are proposed to determine the maximal dimensions reached by the melt and by the solid around the tube.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Thermal Sciences - Volume 112, February 2017, Pages 345-357
نویسندگان
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