本文提出了一端起爆的线型聚能装药射流形成的不定常理论模型。根据这一模型,当金属罩在爆轰波作用下的运动速度为已知时,则不论此速度是否是时间或初始位置的函数,都能得到射流形成时的速度,质量和位置等参数。 按照本文模型,Defourneaux.M.的定常射流形成定常模型是一个简单的特例。我们利用本文的模型对等厚度装药的情况进行了计算,并与实验结果比较,两者符合良好。同时计算结果表明,考虑射流形成的不定常因素,可以较好地解释射流头部的质量堆积和射流内部的反向速度梯度等实验现象。本文的模型可以为线型聚能切割索的设计提供较为准确的理论指导。 In this paper, an unsteady theoretical model for the formation of a linear shaped charge jet at one end is proposed. According to this model, parameters such as velocity, mass and position at jet formation can be obtained whether the velocity is a function of time or initial position, when the velocity of the metal mask is known at detonation. According to our model, Defourneaux’s constant jet formation is a simple case. We use the model in this paper to calculate the thickness of the charge, and compared with the experimental results, both in good agreement. Simultaneously, the calculation results show that considering the unsteady factors of jet formation, the experimental phenomena such as the mass accumulation of the jet head and the reverse velocity gradient inside the jet can be well explained. The model in this paper can provide a more accurate theoretical guidance for the design of linear shaped poly cut cables.