کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
169446 458005 2009 22 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Straining and wrinkling processes during turbulence–premixed flame interaction measured using temporally-resolved diagnostics
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی مهندسی شیمی (عمومی)
پیش نمایش صفحه اول مقاله
Straining and wrinkling processes during turbulence–premixed flame interaction measured using temporally-resolved diagnostics
چکیده انگلیسی

The dynamical processes of flame surface straining and wrinkling that occur as turbulence interacts with a premixed flame were measured using cinema-stereoscopic PIV (CS-PIV) and orthogonal-plane cinema-stereoscopic PIV (OPCS-PIV). These diagnostics provided temporally resolved measurements of turbulence–flame interaction at frame rates of up to 3 kHz and spatial resolutions as small as 280μm. Previous descriptions of flame straining and wrinkling have typically been derived based on a canonical interaction between a pair of counter-rotating vortices and a planar flame surface. However, it was found that this configuration did not properly represent real turbulence–flame interaction. Interactions resembling the canonical configuration were observed in less than 10% of the recorded frames. Instead, straining and wrinkling were generally caused more geometrically complex turbulence, consisting of large groups of structures that could be multiply curved and intertwined. The effect of the interaction was highly dependent on the interaction geometry. Furthermore, even when the turbulence did exist in the canonical geometry, the straining and wrinkling of the flame surface were not well characterized by the vortical structures. A new mechanistic description of the turbulence–flame interaction was therefore identified and confirmed by the measurements. In this description, flame surface straining is caused by coherent structures of fluid-dynamic strain-rate (strain-rate structures). The role of vortical structures is to curve existing flame surface, creating wrinkles. By simultaneously considering both forms of turbulent structure, turbulence–flame interactions in both the canonical configuration and more complex geometries could be understood.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Combustion and Flame - Volume 156, Issue 12, December 2009, Pages 2285–2306
نویسندگان
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