A MODEL FOR DART LEADERS IN LIGHTNING FLASHES
A MODEL FOR DART LEADERS IN LIGHTNING FLASHES
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闪电飞镖领导者的模型
DOI：
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发表时间：
1996
期刊：
影响因子：
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通讯作者：
V. Cooray
中科院分区：
文献类型：
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作者：
V. Cooray
飞镖先导被模拟为一种自传播放电，它在前端携带一个高电场，强到足以在已失效的回击通道中引起电击穿。镖头前端的电场取决于其后面的电流（因此也取决于镖头上储存的电荷）和镖头的速度。因此，通过将该电场等同于在失效的回击通道中引起电击穿所必需的临界电场，可以得到镖首速度、其电流和失效的回击通道的温度之间的关系。导出其传播所通过的返回笔划通道。结果表明，导镖速度取决于失效回击通道的温度和导镖通道上储存的电荷。此外，它表明，飞镖领导人发起时，已失效的回程通道的温度约为1500 K。在该研究中，还估计了镖首在向地面传播时沿着通道速度的变化。结果表明，飞镖领导人接近地面的快速加速度。结果结合最近推出的回击模型，以调查省的变化。先导速度是随后的返回冲程电流的函数。结果表明，镖首速度随回击电流近似线性增加。
: The dart leader was modeled as a self-propagating discharge that carries a high electric field at the :front strong enough to cause electrical break.down in the defunct return stroke channel. The electric field at the :front of the dart leader depends on both the current flowing behind it (and hence on the charge being stored on the dart leader) and the speed of the dart leader. Thus, by equating this field to the critical electric field necessary to cause electric break.down in the defunct return stroke channel, a relationship between the dart leader speed, its current and the temperature of the defunct. return stroke channel through which it propagates was derived. The results show that the dart leader speed depends on the temperature of the defunct return stroke channel and the charge stored on the dart leader channel. Furthermore, it is shown that the dart leaders are initiated when the temperature of the defunct return stroke channel is about 1500 K. In the study variation in the dart leader speed along the channel as it propagates towards the ground is also estimated. The results show a rapid acceleration of dart leader close to ground. The results were combined with a recently introduced return stroke model to investigate the variation in dart. leader speed as a function of the subsequent return stroke current. The results indicate that there is an approximately linear increase in dart leader speed with the associated return stroke current.