Electrical engineering & Electromechanics (Dec 2019)
RESULTS OF INVESTIGATIONS OF THERMAL RESISTIBILITY OF PROTOTYPES OF ALUMINUM ALLOY PANELS OF FUEL TANK OF AIRPLANE TO DIRECT ACTION OF NORMALIZED COMPONENTS OF ARTIFICIAL LIGHTNING CURRENT
Abstract
Purpose. Implementation of calculation-experimental determination of thermal resistibility of walls of aluminum alloy panels of different thickness of fuel tank of the airplane designed in Ukraine to direct action on them of normalized components of current of artificial lightning. Methodology. Theoretical bases of thermophysics, bases of theoretical electrophysics, bases of measuring technique, electrophysics bases of technique of high-voltage and large pulsed currents. Results. The results of calculation-experimental investigations of thermal resistibility of prototypes with the necessary sheeting flat rectangular panels of fuel tank of the designed airplane are resulted measuring 550 mm ´ 800 mm and from 1.2 to 4 mm thick of aluminum alloy B95 is easily soiled to direct action on them in obedience to the operating requirements of normative documents of the USA SAE ARP 5412 and SAE ARP 5416 of A-, B- and C*- component of current of artificial lightning (1А area), and also D-, B- and C*- components of current of artificial lightning (2А area) with the normalized amplitude-temporal parameters (ATPs). It is determined that the tested panels of fuel tank of airplane in 1.2 mm, 1.5 mm and 1.8 mm thick for an area of 1А and 1.2 mm and 1.5 mm thick for an area of 2А are thermally unstable to the direct shots in them of plasma channel of a storm discharge imitated in laboratory terms with the indicated components of current of artificial lightning. It is shown that thermal resistibility to lightning of the tested panels of fuel tank of airplane is determined of ATP shortened protracted C*- components of current of artificial lightning, causing appearance in them of the rounded small holes of melting the radius of rk and depth of hk. For finding by a calculation by the sizes of rk and hk in the indicated panels of fuel tank of airplane, struck in an air atmosphere a direct blow in them the imitated storm discharge, the proper close correlations are recommended. The capacity of these calculation correlations is confirmed results executed by the powerful high-voltage generator of impulsive current of artificial lightning of type of UITOM-1 of model experiments created in Ukraine. Originality. The calculation and experimental estimations of thermal resistibility of flat duralumin panels of fuel tank of the airplane designed in Ukraine are first executed to the direct action on them for the areas of 1А and of 2А of plasma channel of the imitated storm discharge with the normalized indicated documents of ATP flows on it (to the channel) A (D)-, B- and C*- components of current of artificial lightning. Practical value. Taking into account the executed calculation-experimental investigations a practical conclusion is done that for prevention in the case of direct blow in the being in an air atmosphere airplane of plasma channel of lightning with normalized ATPs indicated components of its pulsed current of self-ignition of fuel steams in the examined duralumin tank of the designed airplane and its catastrophe the thickness of wall of an aluminum alloy B95 of this tank with the proper sheeting must make no less than 1.8 mm for the area of 2A and no less than 2 mm for the area of 1A.
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