کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
169233 457985 2011 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Relation between hydroxyl and formaldehyde in a direct-injection heavy-duty diesel engine
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی مهندسی شیمی (عمومی)
پیش نمایش صفحه اول مقاله
Relation between hydroxyl and formaldehyde in a direct-injection heavy-duty diesel engine
چکیده انگلیسی

Formaldehyde and the hydroxyl radical have been recorded simultaneously in a diesel spray in an optically-accessible heavy-duty diesel engine. Formaldehyde (CH2O) was excited by 355 nm radiation, while hydroxyl (OH) was excited around 284 nm. Both laser beams were focussed into a sheet, of which the overlap while traversing the spray was monitored. The experimental results have been compared to simulations. The ignition phase was modeled by a set of homogeneous reactors, while the diffusion combustion phase was simulated by a flamelet approach, viz. a rich partially premixed counterflow diffusion flame. Two situations were tested, one in which the combustion started only after the end of injection (short and early injection) and one with a longer injection duration where injection and combustion partly overlapped in time. In the former, OH initially shows up far from the injector and then quickly proceeds towards the injector. The position of OH varied significantly from cycle to cycle, suggesting that the combustion is partly governed by turbulence. When combustion and injection do partly overlap, the flame structure is much more stable. In both cases, OH and CH2O generally form complementing spatial distributions, indicating that CH2O is consumed locally during the hot combustion.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Combustion and Flame - Volume 158, Issue 3, March 2011, Pages 564–572
نویسندگان
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