Three Dimensional Numerical Simulation of Stepped Leadee by means of Fractal Model

阶梯式引线的分形模型三维数值模拟

• 批准号: 01550220
• 负责人: KAWASAKI Zen-ichiro
• 金额: $ 0.96万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1989
• 资助国家: 日本
• 起止时间: 1989 至 1990
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-01550220/
• 关键词: Fractal; Stepped leader; Lightning; Simulation; Space charge; Winter Thunderstorm; 雷放電路; リ-ダ進展; 雷雲; 冬季雷・夏季雷; 数値シミュレ-ション

Three-dimensional numerical simulations of a stepped leader near the ground surface are carried out by using the Leader Progression Model which is improved by using the novel mathematical concept, Fractal. The finite difference method is applied to the three dimensional Poisson's equation and the stepped leaders, which are initiated at the lower part of the cloud and usually are proceeding toward the artificial constructions on the ground, are simulated to study the theoretical stepped leader progression. The zig-zags and branches of channels, which are believed to be the representative characters of lightning channel, can be simulated in this study.Besides the numerical simulations, lightning channel's features are examined by estimating the Fractal dimensions of lightning channels of still pictures. The average estimated Fractal dimensions is about 1.2, and the estimated Fractal dimension is used to evaluate the numerically simulated results. Through this study the Fractal stepped leader model is completely established.

采用基于分形数学概念改进的Leader Progression模型，对近地表台阶状先导进行了三维数值模拟。本文用有限差分法求解三维泊松方程，模拟了起始于云层下部、通常向地面人工建筑物行进的阶梯状先导，研究了理论上的阶梯状先导过程。闪电通道的曲折和分叉是闪电通道的典型特征，本文在数值模拟的基础上，通过计算静止图像闪电通道的分形维数来研究闪电通道的特征。平均估计的分形维数约为1.2，估计的分形维数被用来评估数值模拟结果。通过本研究，完整地建立了分形阶跃先导模型。

项目成果

河崎 善一郎: "Fractal model for the leader of Lightning" Research letters of Atmospheric Electricity. 9. 63-71 (1989)

川崎善一郎：“闪电领导者的分形模型”《大气电研究通讯》9. 63-71 (1989)。

河崎 善一郎他: "落雷電界波形長時間記録装置の開発と観測結果" 電学論誌(B). 111. (1991)

Zenichiro Kawasaki等：“闪电电场波形长期记录装置的开发和观测结果”电气工程学报（B）111。（1991）。

河崎善一郎: "Fractal stepped leader model and space charge" Journal of Geophysical Research.

Zenichiro Kawasaki：“分形阶梯先导模型和空间电荷”地球物理研究杂志。

河崎 善一郎他: "Fractal Model for the Leader of Lightning" Research letter on Atmospheric Electricity. 9. 63-71 (1989)

Zenichiro Kawasaki 等人：“闪电领导者的分形模型”大气电研究信。9. 63-71 (1989)

竹内 利雄: "大津における夏の雷雲のレ-ダ観測結果(I)不規測な多重セル型雷雲" 天気. 36. 45-50 (1990)

Toshio Takeuchi：“大津夏季雷云的雷达观测结果（I）意外的多单元雷云”天气。 36. 45-50 (1990)