Duan Ji, Yang Xiao, Fan Shaobo, Ji Yaxin, Li Min, Zhi Xiaokun
School of Mechanical and Electrical Engineering, North University of China, Taiyuan, 030051, China.
North Industries Group co., LTD, Xian, 710043, China.
Sci Rep. 2025 Jul 1;15(1):22098. doi: 10.1038/s41598-025-06491-y.
An analytical model of condensed explosives under slow cook-off conditions was established based on the superposition principle and Sturm-Liouville method. The analytical model can quickly and accurately calculate the temperature distribution and ignition location under slow cook-off conditions. The analytical model enables deep probing of the physicochemical mechanisms and complex couplings underlying the thermal ignition of explosives. To validate the analytical model, a slow cook-off experiment was designed and conducted. The calculated normalized axial temperature distribution using the analytical model was compared with the experiment results. The two sets of data were consistent with each other. The finite difference method was used to compute the slow cook-off process and yielded a maximal error of 1% between analytical and numerical results. The comparison results verified the correctness of the model. The results of the analytical model indicate that the temperature increase due to the thermal decomposition of RDX accounted for only 0.2% of the overall temperature at ignition. The ignition locations are related to the length to diameter ratio of the charge. As the length-to-diameter (L/D) ratio of the charge increases, the ignition locations gradually move towards both ends. When L/D ≥ 5.22, the ignition locations are near the thermal boundary.
基于叠加原理和斯特姆 - 刘维尔方法，建立了慢烤条件下凝聚炸药的分析模型。该分析模型能够快速准确地计算慢烤条件下的温度分布和点火位置。该分析模型有助于深入探究炸药热点火背后的物理化学机制和复杂耦合。为验证该分析模型，设计并进行了慢烤实验。将使用分析模型计算得到的归一化轴向温度分布与实验结果进行了比较。两组数据相互一致。采用有限差分法计算慢烤过程，分析结果与数值结果之间的最大误差为1%。比较结果验证了模型的正确性。分析模型的结果表明，RDX热分解导致的温度升高仅占点火时总温度的0.2%。点火位置与装药的长径比有关。随着装药长径比（L/D）的增加，点火位置逐渐向两端移动。当L/D≥5.22时，点火位置靠近热边界。
