کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
7056191 1458051 2015 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Saturation boiling of PF-5060 on rough Cu surfaces: Bubbles transient growth, departure diameter and detachment frequency
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی جریان سیال و فرایندهای انتقال
پیش نمایش صفحه اول مقاله
Saturation boiling of PF-5060 on rough Cu surfaces: Bubbles transient growth, departure diameter and detachment frequency
چکیده انگلیسی
Investigated is the transient growth of discrete bubbles in saturation nucleate boiling of PF-5060 liquid on rough Cu surfaces at an applied heat flux of ∼0.5 W/cm2. The uniformly heated 10 × 10 mm surfaces have an average roughness, Ra = 0.039 μm (smooth Cu), and 0.21-1.79 μm. The transient growth rate, departure diameter and detachment frequency of the discrete vapor bubbles are determined from images captured at 210 fps using high-speed video camera. On smooth Cu, the bubble departure diameter and detachment frequency are 655 ± 40 μm and 31 ± 4 Hz. On the other Cu surfaces (Ra = 0.21-1.79 μm), the measured values of 438 ± 17 μm and 38 ± 3 Hz, respectively, are independent of surface roughness. Results, in conjunction with the experimental nucleate boiling curves, estimate the surface average density of active nucleation sites as a function of wall superheat. For smooth Cu, the density of active sites ranges from 100 to 2000 cm−2, compared to 650-10,000 cm−2 for the rough Cu surfaces. For all surfaces, the active nucleation sites density increases with increasing the wall superheat and/or surface roughness.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Heat and Mass Transfer - Volume 91, December 2015, Pages 363-373
نویسندگان
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