AUTHOR=Xiao Cien , Liu Yakun 

TITLE=Influence of the aerodynamic flow on the dynamic characteristics of a lightning sweeping arc

JOURNAL=Frontiers in Astronomy and Space Sciences

VOLUME=Volume 10 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/astronomy-and-space-sciences/articles/10.3389/fspas.2023.1083158

DOI=10.3389/fspas.2023.1083158

ISSN=2296-987X

ABSTRACT=Lightning arc attachments during the swept strokes are key information in lightning protection design of fast-moving aircraft, wind turbines, rockets, etc. Whereas, numerical modeling has not achieved success to predict the movement of lightning sweeping arcs due to the limited understanding of the complex multi-physics convolution in arc fluid at present. This work builds a dynamic magneto-hydrodynamic (MHD) arc model and couples the electric-magnetic-thermal-force processes to get insights into the lightning arc dynamics. The MHD theory and Newton's second law of motion are also incorporated to describe the movement of arc segments in conditions of aerodynamic flows with different intensities. Results show that, at the center region of arc, the electromagnetic force, thermal buoyancy and aerodynamic force are competitive and all are determiners in predicting the arc displacement. In contrast, at the root region of arc, the electromagnetic force dominates the arc movement with a flow speed under 10 m/s, while aerodynamic force takes the dominant role when the flow speed exceeds 50 m/s. The arc sweeping distance expands from 0.021 m to 1.012 m as the aerodynamic flow increases from 5 m/s to 200 m/s. Meanwhile, when increasing the pitch angle of the arc-connected surface, the arc root becomes more attached to the surface and the sweeping distance is predicted to get reduced. The conclusions contribute to constructing a numerical model to predict the complex arc movement during lightning sweeping strokes.