Insights into the dynamics of wake flame in a freely falling droplet

The combustion of a freely falling dodecane droplet has been studied experimentally in droptower-like facility under ambient conditions. A unique ignition mechanism is used by igniting the pendant mode and releasing it to fall freely. This unveils different type wake flame behavior which explored this study. Initially, transitions from fully enveloped configuration due forward extinction. similar characteristics as laminar lifted triple-flame. As accelerates, stand-off increases continuously. change topology intensity occurs two regimes corresponding diameters. new non-dimensional parameter derived account for local balance between buoyancy momentum diffusion that alters fuel availability. To explain topological evolutions diameters Reynolds numbers, theoretical formulation proposed based on surrounding relative motion. Further, at very high number, stretching or shedding regime occurs, causing momentary spikes interaction with asymmetric vortex induced Bernard–Von Karman instability. Interestingly, height follows buoyant flickering scaling, even momentum-dominant flame. Additionally, circulation build-up mechanisms are shown be responsible events number.