爆炸载荷作用下铀气溶胶形成机理研究

针对铀材料在爆炸载荷作用下形成放射性气溶胶的过程，采用光滑粒子流体动力学方法开展了数值模拟和实验研究。通过将颗粒动力学和SPH方法结合，建立了炸药爆轰作用于铀金属壳的数值模拟模型，以铀材料比内能为气溶胶转化判据，获得了铀材料转化为气溶胶的物理过程，得到了在相同爆炸当量下，不同质量铀材料的气溶胶转化效率，并与实验结果进行了对比分析。结果显示，铀材料在爆炸载荷作用下，当其比内能达到1.9 MJ/kg时，即可认为完全转变为气溶胶，对于本文中的爆炸装置结构形式，当炸药质量为铀材料质量的6倍时，转化率超过90%。实验验证了数值模拟结果，表明该方法能够对铀材料的气溶胶转化过程进行准确描述。

Study on the formation mechanism of uranium aerosol under explosion load

Aiming at the process of uranium material forming radioactive aerosol under the action of explosion load, numerical simulation and experimental research were carried out based on the smoothed particle hydrodynamic method (SPH method). Through the combination of particle dynamics and SPH method, a numerical simulation model of explosive detonation acting on a uranium metal shell was established, which would be used to describe the formation process of uranium aerosol. The specific internal energy of uranium material was used as the aerosol conversion criterion, and the physical process of uranium material conversion into aerosol was obtained. We found two types of damage mode of the uranium under explosive load, one was overall damage when the uranium shell mass was close to the explosive mass, and the other one was crushing damage when the uranium shell mass was much less than the explosive mass. Under the same explosive equivalent, the aerosol conversion efficiencies of uranium materials with different mass were compared with the experimental results. The results show that uranium material can be considered to be completely converted into aerosol when its specific internal energy reaches 1.9 MJ/kg under explosive load. According to the explosive device structure in this paper, when the explosive mass is six times than the mass of uranium, the conversion ratio exceeds 90%. The experimental results have a good agreement with the numerical simulations, which shows that the method used in this paper can accurately describe the aerosol conversion process of uranium materials.