کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6593982 | 1423549 | 2018 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Extreme role of preferential diffusion in turbulent flame propagation
ترجمه فارسی عنوان
نقش شدید انتشار ترجیحی در شعله ور شدن آشفته
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کلمات کلیدی
شعله آشفته، حد آتش سوزی، نفوذ ترجیحی،
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
مهندسی شیمی (عمومی)
چکیده انگلیسی
In this paper we demonstrate the essential role of molecular diffusion in the structure and propagation of turbulent flames. We first show that mixtures whose concentrations are near or beyond the conventional flammability limits can be rendered to burn strongly in turbulence, provided the controlling molecular mass diffusivity of the mixture exceeds its thermal diffusivity, namely the mixture Lewis number (Le) is less than unity. The associated turbulent flame speeds in such cases can be orders of magnitude greater than the corresponding laminar flame speeds, with distinctive finger-shape structures on the flame surfaces. Furthermore, this facilitation effect is completely flipped for Leâ¯>â¯1 mixtures, leading to actual weakening of the nominally enhancing effect of turbulence on their burning intensity. Mechanistically, such opposite effects are consequences of the coupling between preferential diffusion and the wrinkled laminar flamelets constituting the turbulent flame structure.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Combustion and Flame - Volume 188, February 2018, Pages 498-504
Journal: Combustion and Flame - Volume 188, February 2018, Pages 498-504
نویسندگان
Sheng Yang, Abhishek Saha, Wenkai Liang, Fujia Wu, Chung K. Law,