대체천연가스 화염 이미지 역변환에서 전처리 효과

• Published in: 설비공학 논문집, 27(12) Vol. 27; no. 12; pp. 609 - 619
• Main Authors: 안광호(Kwangho Ahn), 송원준(Wonjoon Song), 차동진(Dongjin Cha)
• Format: Journal Article
• Language: Korean
• Published: 대한설비공학회 2015
• Subjects: 기계공학; SUP> chemiluminescence(OH< 자발광; Abel inversion(아벨 역변환); 대체천연가스; lt; Digital image preprocessing(디지탈 영상 전처리); Substitute natural gas(SNG; Flame structure(화염구조); OH< OH
• ISSN: 1229-6422; 2465-7611
• DOI: 10.6110/KJACR.2015.27.12.609

A preprocessing scheme utilizing multi-division of the ROI (region of interest) in a chemiluminescence image during inversion is proposed. The resulting inverted image shows the flame's structure, which can be useful for studying combustion instability. The flame structure is often quantitatively visualized with PLIF (planar laser-induced fluorescence) images as well. The chemiluminescence image, which is a line-integral of the flame, needs to be preprocessed before inversion, mainly due to the inherent noise and the assumption of axisymmetry during the inversion. The feasibility of the multi-division preprocessing technique has been tested with experimentally-obtained OH PLIF and $OH^*$ chemiluminescence images of jet and swirl-stabilized flames burning substitute natural gas (SNG). It turns out that the technique outperforms two conventional methods, specifically, the technique without preprocessing and the one with uni-division, reconstructing the SNG flame structures much better than its two counterparts when compared using corresponding OH PLIF images. The characteristics of the optimum degree of polynomials to be applied for curve-fitting of the flame region data for the multi-division method involving two flames has also been investigated.