Characterization of swirling CNG inverse jet flame in recessed coaxial burner

This paper is concerned with the experimental investigation of swirling inverse jet flame (IJF) characteristics such as visible flame appearance, visible flameheight, temperature distribution, post flame emissions and flame noise in a recessed coaxial burner. Furthermore, variation in lean blowout limits of swirling IJF with aerodynamic swirl number is also reported. Based on the observation of visible appearance of swirling IJF with aerodynamic swirl number, two flame regimes are identified. Besides this, semi-empirical correlations for flame height and lean blowout limits are attempted in this work which can be used for the design and development of future burner systems employing swirling inverse jet flame. Apart from this, an attempt has been made to understand the flow features and flame structure of swirling IJF through numerical simulations. The swirling inverse jet flame configuration studied in this work is capable of establishing compact blue flame with better thermal and emission characteristics and hence can be employed in thermal applications.