Flame stabilization mechanisms and shape transitions in a 3D printed, hydrogen enriched, methane/air low-swirl burner

Flame flow field interaction in non-premixed CH4/H2 swirling flames

“…Similarly, the IRZ size but in premixed swirling methane flames increases compared to the non-reacting case, and this was attributed to the thermal expansion of the burned mixture in the IRZ [21]. Also, in low swirl flames, the dominant contribution to the flow divergence was from the combustion more than the swirling flow itself [24]. Further downstream, the heat release reverses the deceleration trend and generates a slight mean acceleration of the central jet region.…”

“…On the other hand, the flame root extinction due to the flame straining was the dominant factor initiating the flame blow-off; however, the H2 addition was seen to enhance the flame resistance to the strain [23]. Three different flame shapes with varying mechanisms of stabilisation were identified in a hydrogen-enriched methane low-swirl burner [24], namely lifted bowl shape, W-shape, and crown-shape. The transition in shapes and the stabilisation mechanism were mainly depended on the H2-enrichment fraction and the bulk jet velocity.…”

“…Moreover, the effects of hydrogen addition to methane in premixed swirling flames have been recently investigated [21][22][23][24], with the main focus on the flame shape transitions and the stabilisation mechanisms. In a strongly confined swirling flame, with hydrogen fraction increase, it was observed that the flame tip in the outer shear layer gradually propagated upstream and finally anchored to the burner tip, yielding the transition from "V" to "M" flame [21].…”

Experimental Investigation on the Symmetry and Stabilization of Ethanol Spray Swirling Flames Utilizing Simultaneous PIV/OH-PLIF Measurements

“…Due to the excellent evaporation characteristics of ethanol, the chamber and optical window are clean, which is beneficial for performing various laser diagnostic techniques [25][26][27]. The laser diagnostic system is demonstrated in Figure 1b.…”

Numerical Analysis of Hydrogen-Methane Flame in Different Header Types of Premixed Combustors

“…The targets to be overcome in hydrogen-methane combustion are the large amount of NOx generated due to high-temperature flames [10][11][12]. In addition, the application of ultra-lean burn technology as a means to solve this problem may additionally cause flame stabilization problems [13,14]. In order to solve these problems of hydrogen combustion, it is necessary to design a combustor that can reduce the flame temperature.…”