کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
653079 1457487 2015 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Hydrodynamically and thermally developing flow in a rectangular channel filled with a high porosity fiber and rotating about a parallel axis
ترجمه فارسی عنوان
جریان هیدرودینامیکی و گرمایشی در یک کانال مستطیلی پر از فیبر بالا با تخلخل و چرخش در حدود یک محور موازی
کلمات کلیدی
فیبر بالا تخریب، چرخش جریان کانال، پراکندگی حرارتی، نسبت ابعاد،
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی جریان سیال و فرایندهای انتقال
چکیده انگلیسی
Rotating machineries operating at extreme temperature conditions usually need to be cooled internally by involving cooling passages inside them. A potential way to improve heat dissipated by these channels is by filling them with high porosity metal foams ε ≥ 0.89. This proposal is examined numerically by studying developing convective flow across a porous rectangular channel subjected to a uniform wall heat flux and rotating in a parallel mode. In regards to the influence of rotation, both centrifugal buoyancy and Coriolis forces are considered. The generalized model is used to mathematically simulate the momentum equations employing the Boussinesq approximation for the density variation. Moreover, thermal dispersion has been taken into account with considering that fluid and solid phases are in a local thermal non-equilibrium. Computations are performed for a wide range of dimensionless parameters including the aspect ratio, medium porosity, fiber size, rotation number, and solid- to fluid-phase thermal conductivity ratio, while the values of Reynolds and Prandtl numbers are maintained constant. The results reveal that both rotation and thermal dispersion have significant roles in enhancing heat transfer at high levels of porosity and low conductivity ratios. However, these roles are reduced gradually with decreasing the medium porosity or increasing thermal conductivity ratio, but do not completely vanish. In addition, overall performance is improved with either decreasing the aspect ratio for Ar < 1 or increasing it for Ar > 1. Eventually, the worth of using high porosity fibers in enhancing the heat transported through rotating channels has been inspected. An overall enhancement parameter was compared for the current study with a previous study regarding turbulent flow in a rotating clear channel, where it has been confirmed that the current proposal is practically justified and efficient.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Communications in Heat and Mass Transfer - Volume 67, October 2015, Pages 114-123
نویسندگان
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