کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
660703 1458147 2008 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
A boundary layer analysis for entrance region heat transfer in vertical microchannels within the slip flow regime
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی جریان سیال و فرایندهای انتقال
پیش نمایش صفحه اول مقاله
A boundary layer analysis for entrance region heat transfer in vertical microchannels within the slip flow regime
چکیده انگلیسی

A boundary layer integral analysis has been executed to investigate the heat transfer characteristics of natural convection gas flows in symmetrically heated vertical microchannels, under the conditions of large channel aspect ratios, in the slip flow regime. It has been revealed that for low values of Rayleigh number, the entrance region length is only a small fraction of the total channel extent. For higher values of Rayleigh number, however, effects of the developing region are non-trivial, and two counteracting heat transfer mechanisms need to be aptly taken into consideration for interpreting the Nusselt number values. In the present study, the proportionate enhancement in the average Nusselt number with wall-slip effects has been observed to become more prominent for higher values of Knudsen number. However, the relative augmentation in the rate of heat transfer tends to get somewhat arrested for higher values of Rayleigh number, as attributable to the counteracting influences of augmented rates of advective transport and reduced wall-adjacent temperature gradients. For all cases, the boundary layer theory based predictions have been found to agree excellently with the corresponding results obtained from full-scale numerical predictions.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Heat and Mass Transfer - Volume 51, Issues 11–12, June 2008, Pages 3245–3250
نویسندگان
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