Abstract We experimentally and computationally study fire propagation in annular channels whose rectangular cross-sections are a few millimeters wide and high and whose circumferences are hundreds of millimeters long. If a channel is partially filled with a volatile flammable hydrocarbon fluid, locally igniting the vapor above the fluid can start a fire pulse that rapidly propagates around the annulus at hundreds of millimeters per second leaving behind an unexcitable region of depleted vapor, a refractory tail. Further evaporation of the volatile fluid restores the vapor and the corresponding excitable condition, allowing the returning pulse to propagate, provided the channel’s circumference is sufficiently long. Experimentally, we explore this quasi-one-dimensional reaction-diffusion system, discovering simple trends connecting refractory tail length and pulse propagation speed to channel length, height, and width. Computationally, we introduce phenomenological computer simulations that simply reproduce the guided flame and elucidate the underlying physics.
Ren et al. (2026) studied this question.