Mesoscale burner array performance analysis

Abstract

Combustion characteristics of a mesoscale burner array have been studied using several diagnostic and analysis techniques. The array was specifically configured to enhance overall combustion stability, particularly under lean operating conditions, by promoting flame to flame interactions between neighboring elements. The 4 × 4 burner array demonstrated stable operations up to 3 kW and is designed to flexibly accommodate wide range of combustion power outputs by scaling the element dimensions or array size. Flame stabilizing mechanisms were experimentally examined using OH, CH, and CH₂O planar laser induced fluorescence (PLIF) of premixed CH₄ and air flames at operating equivalence ratios between 0.7 and 1.2. A quantitative measure of flame stability was obtained through dynamic mode decomposition (DMD) analysis of high speed OH-PLIF images. Lean blow off limits and emissions were also characterized across a wider range of equivalence ratios to better understand mesoscale burner array combustion characteristics. Lastly, combustion experiments using liquid fuel, pentane (C₅H₁₂), were also carried out. Marked improvement in combustion stability was observed compared to a single swirl-stabilized flame of similar power output. Results indicate mesoscale burner arrays can potentially serve as flexible and scalable next generation propulsion and power generation systems.