A state-of-the-art review of lab-scale inverse diffusion burners & flames: From laminar to turbulent

Based on the previous work, this paper presents a thorough review of the laboratory studies of IDF (inverse diffusion flame), introducing its history, its current development and foreseeing the problems to be solved in future. The review is focused on the flow and combustion behaviors during the transition of IDF from laminar to turbulent, which are well documented in the studies of IDF impingement heat transfer, and thus is aimed to provide guidance for expediting future studies of soot formation in turbulent IDF. As a flame, IDF is influenced by the parameters of burner, fuel/oxidizer flows and chemical reactions, which can be overally classified into three types, i.e. geometrical, fluidynamic and combustion parameters. Based on these parameters, this review copes with a number of issues like IDF burner design, features of burner geometry, analysis of flow dynamics, flame structure and characters of thermal field. Firstly, the review focuses the burner geometric features, and presents a full picture of the burner design evolution in the past decades. Then, an attempt will be made to encompass the mixing mechanism between fuel and oxidizer, at either molecular or macroscopic levels. Next, an introduction is made to various flame patterns produced and their thermal and combustion characteristics. After this, the fluid mechanics and particular fluidynamic features of IDF will be fully recognized. Finally, the combustion and usages of various IDFs will be visited, gaining information of both local and global fluidynamic and thermal behaviors of IDF. Through this review work, it is intended to address the investigation need for future challenges in laboratory IDF studies as well as to put IDF into better practical applications.