Study On The Deflection Effect Of Dynamic Armor Electromagnetic Field To Flying Object

The survivability of naval ships is the primary foundation for ensuring ships to maintain the fighting capacity in the complex battlefield environment.With the development of antiarmor weapons,armor-picering capability of modern anti-ship missile has been greatly improved,which causes the increasingly difficult to meet the protection demand of modern ships for traditional armor structure.As a protection means,the electromagnetic armor has played an increasingly significant role in modern ships protection.Particularly,it is a novel protection means for weapons and equipment to deflecting the incoming projectile using the electromagnetic force acting on the projectile between two polar plates.This protection means,named dynamic electromagnetic armor,consists of two polar plates with a distance,which are connected to two poles of electric energy storage module respectively.The projectile occures deflection under the action of electromagnetic force when penerating into two plates,then the attacking energy density is reduced and armor picering ability is weakened.In this way,the incoming projectile is defeated in a combination protection means.In this paper,the system circuit is theoretically analyzed,and the electrical parameters are calculated by empirical formula.The influence of varied parameters on discharge current is discussed,which indicates that the current discharge period is mainly determined by inductance and capacitance,and the current decreases with the increase of circuit resistance and inductance.Based on finite element method,the limitation of traditional line current theory is discussed used in electromagnetic armor calculation.By introducing the concept of inductance gradient,a novel electromagnetic force calculation formula is set up which is adaptive to 3-dimensional electromagnetic armor.The formula can reveal the relationship between deflection electromagnetic force and current,plate spacing,projectile penetration angle and plate width.In most cases,the error is about 10% compared with finite element simulation,so it is reliable for electromagnetic force calculation.The dynamic equation of projectile deflection is derived based on rigid body dynamic,which has taken the coupling problem into account between motion field and electromagnetic field.The equation is solved with intercross method and the validity of the equation is verified by finite element simulation.The arc starting experiment?static electromagnetic force deflection experiment and quasi static electromagnetic force simulated experiment have been carried out under the condition of controllable factors.Some key circuit parameters are obtained,and the deflection effect is verified under the electromagnetic force,then deflection time history and the electromagnetic force are gained and compared with the theory results.The total resistance is corrected by measured current,and the calculation model of electromagnetic force is modified to fit the experiment structure.The experiment results show that the arcing gap is increased by 1mm when the load voltage is increased by 2kV~3kV.A large contact resistance is produced by sliding contact in the circuit.With the continuous discharge of the circuit,the resistance increases gradually due to the ablation of the contact position.And in this condition,the discharge current in later period under the high voltage is less than the low voltage one abnormally.