Study on the coupling mechanism between dispersed fuel flow and central thermal field

During the dispersion of liquid fuel, the high-intensity energy field released by central charge detonation can easily trigger premature-ignition of the fuel cloud, leading to the early release of chemical energy and weakening the destructive power of detonation. In this paper, a dynamic temperature field calculation model based on specific internal energy during central charge detonation is proposed, achieving a relative error of less than 1.3 %–1.9 % compared to experimental values and effectively capturing transient temperature fields. Using this model, the temperature field and its coupling with the concentration distribution of the dispersed fuel cloud in a Fuel Air Explosive (FAE) device were obtained. It is shown that when the detonation products temperature exceeds the ignition temperature of propylene-oxide (693.15 K) and the fuel cloud concentration falls within the sensitive range of 72–959 g/m³, local mixed zones can initiate self-sustained combustion through the synergistic effects of heat conduction and droplets evaporation. Accordingly, a combustion initiation mechanism and a premature-ignition prediction model for the fuel dispersion process are proposed. Furthermore, a hazard classification of the spatiotemporal regions prone to premature-ignition was conducted. These insights provide important guidance for improving fuel utilization efficiency and enhancing the power of FAE.