2020 Volume 37 Issue 4 Pages 370402-
Cool flame dynamics is simulated considering gas-liquid equilibrium with the ambient temperature of 550 K and 600 K, and pressure of 1.0 atm. The ignition delay time of the droplet pair are longer than that of the single one, and the ignition of the droplet pair occurred from the outside of the droplet for 550 K. Meanwhile, significant difference in each ignition delay time was not found, and the ignition of the droplet pair occurred almost spatially uniform for 600 K while the temperature rising of the inter-droplet region slightly led that of the outer region. It is thought that species and heat transfer are not dominant for 600 K due to a higher reaction rate. As the noteworthy behavior, the multi-stage cool flame ignition was found for 600 K. It is thought that the long ignition delay time cause supplying the enough fuel, which contributes to keep cool flame burning for 550 K. In contrast, cool flame cannot be supported due to insufficient fuel, and it should become weak after ignition for 600 K. The subsequent accumulation of the chain agent should reactivate the next ignition.