Explosion behaviors of aviation kerosene in a 20-L spherical vessel

Aviation kerosene is the main fuel in aerospace industry. In order to investigate the explosion behaviors of aviation kerosene, the explosion experiments were conducted using the 20-L liquid explosion testing system. The influence factors, including mist concentration C_AV, ignition delay time t_d, liquid injection pressure P_i, and ignition energy E were discussed, and the explosion mechanism of aviation kerosene droplet was analyzed as well. Experimental results showed that minimum explosible concentration (MEC) of aviation kerosene mist was 140 g/m³. The maximum explosion pressure (P_ex), maximum pressure rise rate ((dP/dt)_ex), explosion index (K_St) and average flame propagation velocity (V_AF) first rose and then declined, while combustion time (t_c) showed the opposite trend with increasing C_AV. 600 g/m³ was the optimal concentration. P_ex, (dP/dt)_ex, K_St and V_AF showed an inverted “U-shaped” trend, while t_c presented a positive “U-shaped” trend with t_d. The optimal ignition delay time was 100 ms. P_ex, (dP/dt)_ex, K_St, and V_AF all gave a linear positive correlation, while t_c presented a linear negative correlation with both P_i and E. The influence of P_i and E on (dP/dt)_ex, K_St, and V_AF was greater than that on P_ex and t_c. V_AF could be used to approximate the flame propagation velocity in simplifying calculations. The relationship between K_St, V_AF and C_AV, t_d, P_i and E was also concluded. The mass evaporation rate m¯, the trend of the diameter over time dr/dt and the trend of the temperature over time dT/dt of aviation kerosene droplet were obtained. The evaporation model and multizone combustion model of aviation kerosene vapor-liquid two-phase mixture was discussed in detail.