کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10264354 | 457804 | 2015 | 9 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
LES of longitudinal and transverse self-excited combustion instabilities in a bluff-body stabilized turbulent premixed flame
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
مهندسی شیمی (عمومی)
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: LES of longitudinal and transverse self-excited combustion instabilities in a bluff-body stabilized turbulent premixed flame LES of longitudinal and transverse self-excited combustion instabilities in a bluff-body stabilized turbulent premixed flame](/preview/png/10264354.png)
چکیده انگلیسی
Combustion dynamics of a V-flame in an afterburner-type configuration are investigated using high-order compressible large eddy simulations (LES) and compared to experimental results. Both self-excited longitudinal (100Â Hz) and transverse (1400Â Hz) modes observed in the experiments are captured by LES and instability mechanisms are discussed. LES results for all modes are compared to a Helmholtz solver output, showing that the transverse mode appearing in the LES is the 1Lx-2Ty-0Tz eigenmode of the chamber, affecting the velocity field symmetrically. The 1Lx fluctuation causes a symmetric flame roll-up which increases heat release rate fluctuations, closing the feedback loop. The 2Ty component of the mode is active along the flame holder axis and causes not only transverse fluctuations but also a reorganization of the mean flame along two main zones located on both sides of the zero acoustic velocity plane, a feature that has not been reported before. Dynamic mode decomposition (DMD) is used to extract the structure of the transverse mode from LES snapshots which is found to match the Helmholtz solver prediction. This study confirms the capacity of high-order LES to capture not only low-frequency oscillations but also high-order frequency transverse modes in combustion chambers.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Combustion and Flame - Volume 162, Issue 11, November 2015, Pages 4075-4083
Journal: Combustion and Flame - Volume 162, Issue 11, November 2015, Pages 4075-4083
نویسندگان
Abdulla Ghani, Thierry Poinsot, Laurent Gicquel, Gabriel Staffelbach,