Genesis of return stroke current evolution at the wavefront

Raysaha, Rosy Balaram and Kumar, Udaya (2011) Genesis of return stroke current evolution at the wavefront. In: 2011 7th Asia-Pacific International Conference on Lightning (APL), 1-4 Nov. 2011, Chengdu.

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Abstract

The channel dynamics at the wavefront is quite complex and is basically responsible for the evolution of return stroke current. The physical processes that actually contribute to the current evolution are not very clearly known. The enhancement of channel conductance at the wavefront is necessary for the current evolution and hence, return stroke. With regard to this, several questions arise like: (i) what causes the enhancement of this conductance, (ii) as the channel core temperature and electrical conductance are closely related, does one support the other and (iii) is the increase in core temperature on the nascent section of the channel is the result of free burning arc of the wavefront just below. These questions are investigated in detail in this work with appropriate transient thermal analysis and a macroscopic physical model for the lightning return stroke. Results clearly indicate that the contribution from the thermal field of the wavefront region to the adjacent nascent channel section is negligible as compared to the field enhancement brought in by the same. In other words, the whole process of return stroke evolution is dependent on the local heat generation at the nascent section caused by the enhancement of the electric field due to the arrival of the wavefront.

Item Type:	Conference Paper
Publisher:	IEEE
Additional Information:	Copyright 2011 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.
Department/Centre:	Division of Electrical Sciences > Electrical Engineering
Date Deposited:	10 May 2012 11:03
Last Modified:	10 May 2012 11:03
URI:	http://eprints.iisc.ac.in/id/eprint/44375

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