کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
7935172 | 1513048 | 2018 | 17 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Thermal performance in solar air heater with perforated-winglet-type vortex generator
ترجمه فارسی عنوان
عملکرد حرارتی در بخاری خورشیدی با ژنراتور گرداب نوعی سوراخدار بال بالدار
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی انرژی
انرژی های تجدید پذیر، توسعه پایدار و محیط زیست
چکیده انگلیسی
An experimental and numerical study of turbulent convective heat transfer in a solar air heater duct with winglet-type vortex generators (WVGs) placed on the absorber plate is presented. Air as the test fluid enters the duct having a uniform wall heat-flux applied on the upper wall or the absorber plate with Reynolds number from 4100 to 25,500. Two types of WVGs are introduced: rectangular (RWVG) and trapezoidal (TWVG) WVGs, in order to create multiple vortex flows along the duct. The WVG parameters in the present study include two relative height (BRâ¯=â¯e/Hâ¯=â¯0.2 and 0.48), three longitudinal pitch ratios (PRâ¯=â¯Pl/Hâ¯=â¯1, 1.5 and 2) and a single attack angle, αâ¯=â¯30°. The experimental result reveals that the RWVG with BRâ¯=â¯0.48 and PRâ¯=â¯1 provides the highest heat transfer and friction factor at about 7.1 and 109.5 times above the flat duct, respectively while the TWVG with BRâ¯=â¯0.2 and PRâ¯=â¯1.5 yields the maximum thermal performance around 1.84. Then, to improve the performance by reducing the substantial pressure loss, both the WVGs with BRâ¯=â¯0.48 and PRâ¯=â¯1.5 are modified to be perforated rectangular and trapezoidal winglet-type vortex generators (P-RWVG and P-TWVG) with four different punched hole/pore diameters (dâ¯=â¯1, 3, 5 and 7â¯mm) on their central area. The investigation indicates that among the perforated WVGs, the P-RWVG at dâ¯=â¯1â¯mm yields the highest heat transfer and friction factor up to 6.78 and 84.32 times higher than the smooth duct but the best thermal performance of about 2.01 is found for the P-TWVG with dâ¯=â¯5â¯mm. To explore the flow and heat transfer pattern, a 3D numerical flow simulation is performed and validated with available measurements where both the numerical and measured results are in good agreement.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Solar Energy - Volume 170, August 2018, Pages 1101-1117
Journal: Solar Energy - Volume 170, August 2018, Pages 1101-1117
نویسندگان
Sompol Skullong, Pitak Promthaisong, Pongjet Promvonge, Chinaruk Thianpong, Monsak Pimsarn,