A modified shadowgraph imaging setup equipped with a high-speed camera is utilized to achieve a numerical evaluation of temperature, number densities of molecules, ions and electrons to the refractive-index of negative non-breakdown streamer in rapeseed insulating oil for revealing the dynamics of streamer propagation. The non-breakdown streamer is found reaching fairly high speed of 3.01-4.66 km/s during 0-1.7 μs. The following 10 μs is dominated by streamer propagation with the grayscale decreasing continuously for the entire streamer. The dissipation is identified starting at ca. 11.7 μs in the stem region while the head of streamer remaining further propagation. This is followed by a dissipation expansion from the stem to the head regions. The double-unsaturated triglycerides are evidenced as the main ionization components in the non-breakdown streamer, which aid to identify the temperature variations, instead of electrons, positive ions, or dissociation of molecules, contribute mainly to the refractive index drop of the streamer. The mapping for the temperature distribution of streamer is resultantly possible and provides the insight to ascertain the inhomogeneous migration of electrons the kinetic superiority for the streamer evolution dynamics.

中文翻译：

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负雷电冲击电压下天然酯中非击穿流光传输的阴影成像数值模拟


利用配备高速相机的改进阴影图成像装置，对菜籽绝缘油中的温度、分子、离子和电子的数密度以及负非击穿流光的折射率进行数值评估，以揭示油菜籽绝缘油中负非击穿流光的动态。流光传播。发现未击穿的拖缆在 0-1.7 μs 期间达到了 3.01-4.66 km/s 的相当高的速度。接下来的 10 μs 主要是流光传播，整个流光的灰度持续下降。耗散从大约开始确定。茎部区域为 11.7 μs，而流光头部仍继续传播。随后是从茎部到头部区域的耗散扩张。双不饱和甘油三酯被证明是非击穿流光中的主要电离成分，有助于识别温度变化，而不是电子、正离子或分子解离，主要导致流光的折射率下降。因此，流注温度分布的映射是可能的，并为确定电子的不均匀迁移和流注演化动力学的动力学优势提供了见解。