Study On The Structure And Layout Of Button Type Diverter Strip For Lightning Protection

The lightning voltage can reach up to 100 million volts,the peak current can reach 200kA,which brings a certain safety hazard to the normal flight of the aircraft,so it is necessary to protect the aircraft from lightning.The lightning protection of the radome is an important part of the lightning protection of the aircraft.The button lightning splitter is the key component of the lightning protection of the radome.The transmission efficiency of this splitter is high,but its lightning protection ability is greatly affected by its design structure and distribution on the surface of the radome.Based on the test method of GJB3567-1999 "lightning protection test for military aircraft" and the test requirements of SAE ARP5416 "lightning test method for aircraft",the breakdown voltage test of button type lightning splitter,lightning current and lightning impulse test are carried out respectively,and the breakdown electricity of button lightning splitter under different design parameters is obtained.The damage of mine voltage and lightning current.Combined with the lightning shielding test conditions of the radome in the above standard,the lightning shielding model of the radome is established in the finite element software COMSOL for a certain type of airborne radome.From three aspects of the length,quantity and distance between the splitter and the antenna and the cover body,the distribution of the button type lightning splitter is simulated and analyzed around the antenna.The influence of the electric field on the lightning protection capability of the radome is obtained,and the validity of the simulation results is verified by the test.By establishing the lightning shielding model of the radome in the Microwave Studio of the finite element software CST,the influence of the lightning protection design parameters on the permeability of a certain type airborne radome is studied.The main conclusions of this paper are as follows:(1)The breakdown voltage of the button type lightning splitter increases with the increase of the length,the larger the metal button spacing is,the faster the increase rate is,the smaller the spacing is,the slower the rate is.The length of button type lightning splitter and the spacing of metal buttons increase,and the breakdown voltage level of the splitter strip is increased gradually,and the direct effect of lightning and lightning current is aggravated.(2)For this type of radome,with the increase of the length and number of button lightning splitter,the electric field intensity in the vicinity of the antenna decreases and the length exceeds about 40%of the antenna's height.This trend slows down,and the trend is also slowed down after the number reaches the minimum value of the maximum interval of the split splitter.With the increase of the distance between the antenna and the hood,the field strength near the antenna will increase slightly.(3)The type of radome surface button type lightning shunt length within 900mm,maintain a transparent cover rate.The penetration rate of the radome increases linearly with the increase of the number of the splitter,and the decrease rate of the high frequency antenna is slower than that of the low frequency antenna.When the antenna deviation angle is closer to 0 or 90 degrees,the penetration rate of the radome is relatively high.While the antenna offset angle is 45 degrees,the penetration rate of the radome is relatively low,and the effect of the high frequency antenna migration on the radome permeability is less than that of the low frequency antenna.