کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
667008 1458581 2008 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Elongated bubbles in microchannels. Part I: Experimental study and modeling of elongated bubble velocity
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی جریان سیال و فرایندهای انتقال
پیش نمایش صفحه اول مقاله
Elongated bubbles in microchannels. Part I: Experimental study and modeling of elongated bubble velocity
چکیده انگلیسی

The velocity of elongated vapor bubbles exiting two horizontal micro-evaporator channels with refrigerant R-134a was studied. Experiments with tube diameters of 509 and 790 μm, mass velocities from 200 to 1500 kg/m2 s, vapor qualities from 2% to 19% and a nominal saturation temperature of 30 °C were analyzed with a fast, high-definition digital video camera. It was found from image processing of numerous videos that the elongated bubble velocity relative to that of homogeneous flow increased with increasing bubble length until a plateau was reached, and also increased with increasing channel diameter and increasing mass velocity. Furthermore an analytical model developed for a diabatic two-phase flow, has been proposed that is able to predict these trends. In addition, the model shows that the relative elongated bubble velocity should decrease with increasing pressure, which is consistent with the physics of two-phase flow.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Multiphase Flow - Volume 34, Issue 6, June 2008, Pages 590–601
نویسندگان
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