Research On UAV's Surface Current And Electromagnetic Field Based On Raiden EMP

At present,unmanned aerial vehicle(UAV)has developed into UAV system,which can accomplish many tasks,such as information collection,attack and support,seizing battlefield electromagnetic force,providing early warning,target guidance and so on.It plays an important role in military activities of various countries.Lightning,as a natural discharge phenomenon in electromagnetic environment,has the characteristies of high voltage,high current and instantaneous electromagnetic field.As an important weapon launching,army transportation,intelligence reconnaissance and battlefield command platform in modem warfare,UAV loads a large number of electronic and electrical equipnient.Once attacked by thunder and lightning electromagnetie pulse,the equipment will be damaged lightly and even the aircraft will be destroyed or killed heavily,which will have an impact on the development of the war situation.In this paper,the indirect lightning effect of UAV is studied,and the following work is accomplished:1.The direct and indirect effects of lightning on aircraft are analyzed.The theoretical basis of lightning electromagnetic field is introduced*Four different numerical methods of electromagnetic field are used to establish the mathematical model of lightning environment.By comparing the main application scope,advantages and disadvantages of the four numerical methods,the transmission line matrix method is finally adopted to study the indirect lightning effect of UAV.2.The basic principle of lightning strikes on UAV and the principle of lightning strikes zoning are analyzed.The model of lightning attachment zoning is built by electrostatic field method.The head,wing tip and tail tip of all-metal UAV are simulated by CST simulation platform.The results of lightning strikes attachment zoning of UAV are obtained.The indirect lightning effects of UAV are studied.3.The transmission line matrix method is used to study the indirect lightning effect of UAV.The indirect lightning effect model of UAV is built by CST simulation platform,and the surface current and electromagnetic field of all-metal UAV under three different lightning strike paths are calculated in detail.By analyzing the surface current distribution,magnetic field distribution and electric field distribution of three different lightning paths,the factors affecting the surface current density,magnetic field intensity and electric field intensity of UAVs and their distribution laws are obtained.4.Using the theory of multi-conductor transmission line,the coupling of cables and cables in the indirect lightning effect of UAV is studied.Based on the CST simulation platform,the coupling model of cables in UAV is built.Three typical cables,single cable,coaxial line and twisted pair cable,are selected.By analyzing and comparing the coupling current and voltage peaks of cables in single lightning EMP incident direction and different lightning EMP incident directions,the factors affecting the cables in UAV under lightning strike are obtained.