کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
645643 | 1457145 | 2015 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Effect of external surface emissivity on flame-splitting limit in a micro cavity-combustor
ترجمه فارسی عنوان
اثر تابش خارجی سطح بر روی شعله در یک حفره ریز
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کلمات کلیدی
احتراق میکروسکوپ، حفره، محدود شدن شعله شعله از دست دادن حرارت، تجمع گرما،
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
جریان سیال و فرایندهای انتقال
چکیده انگلیسی
Heat transfer processes are of significance for combustion in microscale channel. In the present paper, three different values (i.e., ε = 0.1, 0.5 and 0.92) are selected to numerically investigate the effect of external surface emissivity on the flame-splitting limit (the critical velocity when the combustion efficiency drops to 80%) using Fluent 6.3. The results demonstrate that the flame-splitting limit has a negatively monotonic variation trend with the external surface emissivity. This feature is interpreted from viewpoints of heat-loss from the exterior wall and heat recirculation through the upstream wall. The analyses show that the heat-loss ratio decreases with the reduction of external surface emissivity, which gives rise to a more intense reaction in the cavity and a higher wall temperature level. Therefore, more heat is recirculated to upstream wall and a better preheating of the fresh mixture can be achieved. Consequently, the chain reactions of H2/air mixture start earlier and the reaction rates are much faster for a smaller surface emissivity. The combined actions of heat loss and heat recirculation lead to a faster consumption of the hydrogen fuel at the flame tip, and a larger flame-splitting limit can be obtained for a smaller surface emissivity.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Applied Thermal Engineering - Volume 83, 25 May 2015, Pages 8-15
Journal: Applied Thermal Engineering - Volume 83, 25 May 2015, Pages 8-15
نویسندگان
Wei Yang, Aiwu Fan, Jianlong Wan, Wei Liu,