کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
658389 1458094 2012 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
An experimental investigation of flow and heat transfer characteristics over blocked surfaces in laminar and turbulent flows
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی جریان سیال و فرایندهای انتقال
پیش نمایش صفحه اول مقاله
An experimental investigation of flow and heat transfer characteristics over blocked surfaces in laminar and turbulent flows
چکیده انگلیسی

Flow and heat transfer measurements were obtained over a blocked surface mounted on a low speed wind tunnel in order to investigate the combined the effects of free stream velocities and the different size of rectangular blocks on the flow and heat transfer characteristics. Mean velocity and turbulence intensities were measured by a constant temperature anemometer and wall temperatures by copper-constant thermocouple and static pressures by a micro-manometer, respectively. It was found that the flow separations and reattachments were occurred before the first blocks, on the first blocks, between blocks and after the last blocks. The blocked surface area and flow separation caused not only heat transfer enhancement but higher turbulence levels as well. The average Stanton numbers, for block heights of 10, 15 and 20 mm, were higher than those of flat surface by 82%, 95%, 113% in laminar and 27%, 38%, 50% in turbulent, respectively. These results showed that heat transfer enhancement on the blocked surface increased with block heights and become more pronounced in laminar than that of turbulent flows.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Heat and Mass Transfer - Volume 55, Issues 13–14, June 2012, Pages 3641–3649
نویسندگان
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