Accession Number : ADA190507
Title : The Growth Potential of Corona Discharges from Aircraft Flying in Precipitation.
Descriptive Note : Final scientific rept. 1 Jan 83-31 Dec 85,
Corporate Author : UNIVERSITY OF MANCHESTER INST OF SCIENCE AND TECHNOLOGY (ENGLAND)
Personal Author(s) : Bicknell, J A
Report Date : 12 Nov 1987
Pagination or Media Count : 149
Abstract : The behaviour of positive streamers in fields near and above the stability field has been studied in quasi-uniform fields of up to 18cm in extent with the aim of producing a model of the behaviour so that predictions can be made for much greater distances. In particular the evolution in air of free charge produced by the propagation has been monitored and the effect of pressure and propagation distance on this evolution studied. A frequency Gamma or coefficient gamma has been defined and measured which characterises the growth of free charge. The Schockley-Ramo theorem has been used to analyse the data which not only provides values for other relevant parameters such as attachment coefficient and streamer velocity but also provides a novel way of observing prebreakdown streamer modes. A model has been constructed which adequately accounts for the observed behaviour in small gaps but which predicts unrealistically large amounts of free charge in large gaps (1m). This suggests that some other mechanism might predominate in this case; an increase in electron density leading to channel thermalisation is suggested as a possibility.
Descriptors : *AIRCRAFT , *ELECTRICAL CORONA , *FLIGHT , *ELECTRIC DISCHARGES , *RAINFALL , ATTACHMENT , COEFFICIENTS , ELECTRON DENSITY , PROPAGATION , RANGE(DISTANCE) , STABILITY , ATMOSPHERIC ELECTRICITY , GREAT BRITAIN , MODELS , COMPUTER PROGRAMS , GREAT BRITAIN
Subject Categories : Atmospheric Physics
Distribution Statement : APPROVED FOR PUBLIC RELEASE