Dispersion and secondary explosion model of propylene oxide droplets/aluminum powder under explosion driving: Considering the initial flow field

The dispersion and explosion characteristics of multiphase particles under explosion-driving hold significant importance for safety design and accident prevention in the chemical industry field. In order to solve the problems of discontinuity, incompleteness of flow field conditions and significant near-field errors in the existing numerical models, a dispersion and secondary explosion model of propylene oxide droplets/ aluminum powder under explosion driving is built. The model performs continuous computations for the four stages of initial dispersion, cloud development, concentration distribution, and secondary explosion. The model considers the initial flow field conditions, effectively reducing the near-field computational error to within 10 %. The dispersion and explosion processes of mixed fuel under three conditions (static, with wind speed and with falling speed) are studied through experiments and numerical models. The results show that under the initial wind speed, the dispersion radius of the downwind area extends by 16.8 %. The burnout rate increases by 15.0 %, and the peak overpressure of the secondary explosion rises by 4.2 %. Under the initial falling speed effect, the concentration distribution of the fuel cloud becomes more uniform. The proportion of the gas phase increases. It has been verified that the velocity change of the initial flow field can influence the stripping and evaporation effects of droplets, thereby strengthening the explosive properties of the cloud.