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ISSN Online: 2377-424X

ISBN Print: 978-1-56700-474-8

ISBN Online: 978-1-56700-473-1

International Heat Transfer Conference 16
August, 10-15, 2018, Beijing, China

RADIATIVE TRANSFER DURING A PULSED LIGHTNING ARC ON A METALLIC PLATE

Get access (open in a dialog) DOI: 10.1615/IHTC16.rti.022943
pages 8279-8286

Abstract

Lightning electrical arcs lead to high temperature and high pressure air plasmas where radiation is a dominant energy transfer mechanism. The aim of this communication is to determine the radiative flux induced by this plasma during its interaction with a given material, and to discuss its importance in the energy balance at the wall. This is of prime interest for the study of the lightning on aircrafts and other aeronautical vehicles. Previous experiments using a laboratory pulsed lightning arc generator, enabled the characterization of the cylindrical arc in terms of temperature, electron density, and pressure radial distributions, and their temporal evolution during the few tens of microseconds corresponding to the pulse duration. These measurements are used here to compute the incident radiative flux on a metallic plate used as one of the two electrodes (cathode) in the experiment. Line by line calculations, in association with a ray tracing method in finite axisymmetric geometry, and with accurate plasma spectroscopic data, especially developed for this type of applications, are used for the simulations. The calculations are carried out at high spectral resolution for a high peak current of 100 kA. The obtained radiative fluxes are compared to estimated values of the electrical flux and power. The comparisons show that radiative flux from the plasma column is very important in the energy balance at the surface of the wall, and should not be neglected as it is generally assumed for the cathode region at moderate current intensities.