Study On The Influence Of Lightning Current Distribution Effect Of The Cabin

During the lightning test of the entire plane,After the lightning current passes through the plane,it must enter the ground port through a return path composed with return conductor.The coaxial loop is used as the return path of lightning current.However,the particularity structure of the coaxial circuit will have an impact on the distribution effect of lightning current on the fuselage.The unreasonable structure may affect the result of the entire plane lightning test.Therefore,it is necessary to study the influence of coaxial loop on the effect of the lightning current distribution on fuselage.This paper studies two aspects of the lightning current distribution effect on airplane cabin with coaxial loop:the influence of coaxial loop on the lightning current distribution on the surface of aircraft cabin,and the influence of coaxial loop on the coupling characteristics of cabling in the cabin.The specific research contents include:Firstly,this paper expounds the analysis method of the indirect effect of the aircraft,and focuses on the basic principle and method of the entire plane test.Then the simulation model of the cabin was built,and the structure of the coaxial loop was designed,By changing the structural layout of the r coaxial loop,study the variation of surface current density distribution on the cabin,The formula for calculating the degree of the unevenness of current density distribution on the cabin surface is deduced and verified by simulation.Then the cable was laid inside the cabin model,by changing the structural layout of the coaxial loop,to explore the variation law of induction current of internal cable.Based on the simulation results,The influence of the degree of the unevenness of current density distribution on the induction current of internal cable is studied.Finally,making simulation module test piece,designing the lightning waveform generator,and carrying out the contraction of the cabin to the lightning current test.The experimental results verify the simulation results.Under the simulation model and test layout,the main conclusions are as follows:(1)When the number of returned conductors and the distance from the return conductor to the cabin are increased,the degree of the unevenness of current density distribution of the cabin will reduce.(2)When the number of returned conductors and the distance from the return conductor to the cabin are increased,the induction current with the internal cable in the cabin will reduce.(3)When the degree of the unevenness of current density distribution on the cabin surface is less than 30%,the measurement error of the entire plane lightning test is acceptable.