Interaction of Two Micro-slot Flames: Heat Release Rate and Flame Shape

14th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications

物理学;能源学

Kuwana, K.^1 ; Kato, S.^2 ; Kosugi, A.^1 ; Hirasawa, T.^2 ; Nakamura, Y.^3

Department of Chemistry and Chemical Engineering, Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata

992-8510, Japan^1

Department of Mechanical Engineering, Chubu University, 1200 Matsumoto-cho, Kasugai, Aichi

487-8501, Japan^2

Department of Mechanical Engineering, Toyohashi University of Technology, 1-1 Hibarigaoka, Toyohashi, Tempaku, Aichi

441-8580, Japan^3

关键词: Computational fluid dynamics simulations;    Diffusion Flame;    Flame shapes;    Heat Release Rate (HRR);    Heat sources;    Line sources;    Micro slots;    Total heat release;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/557/1/012079/pdf
DOI  :  10.1088/1742-6596/557/1/012079

来源: IOP

【 摘 要 】

This paper studies the interaction between two identical micro-slot diffusion flames. Here, we define a micro-slot flame as a slot flame of which the slot width is less than about 1 mm. Because of its smallness, a micro-slot flame has a high heating density and can be used as a small heat source. However, the heat release rate of a single micro-slot flame is limited, and therefore, multiple micro-slot flames may be used to increase total heat release rate. As a first step, this paper considers a situation in which two micro-slot flames are used with certain burner spacing. When two diffusion flames are placed closely, flame shape changes from that of an isolated flame. Studying such flame shape change and resultant change in total heat release rate is the topic of this paper. Experiment is conducted and total heat release rate is measured by integrating CH∗ chemiluminescence recorded using a CCD camera and an optical filter of the wavelength of 430 nm. Two different burner materials, copper and glass, are tested to study the effect of heat loss to burners. An analytical model is applied to predict flame shape. In addition to the classical Burke-Schumann assumptions, two slot flames are modeled as line sources with zero width, enabling a simple analytical solution for the critical burner spacing at which two flames touch each other. The critical burner spacing is a key parameter that characterizes the interaction between two micro-slot flames. Computational fluid dynamics (CFD) simulations are then conducted to test the validity of the present theory. CFD results are favorably compared with the theoretical prediction.