| When the projectile impact the target plate at high speed,extreme conditions produced at the point of contact between the projectile and the target plate.The projectile materialand target material are impacted,sheared,crushed and subjected to rapid pressure and temperature changes.The heated material reaches a sufficiently high of the temperature will produce light,the phenomenon known as the impact "flash",the flash is the impact of the initial conditions and target material properties of the "fingerprint.".In order to study the influence of the hypervelocity impact of spacecraft,use of transient optical fiber pyrometer measurement system and high-speed camera imaging system combined with two-stage light gas gun to carry out the different impact parameter under the condition of 2A12 Al ball projectile hypervelocity impact in the process of 2A12 Al target near the point of impact flash research on the effects of radiation characteristics.Based on Planck ’s Blackbody Radiation Theory,the curve of flash radiation intensity with time was obtained through MATLAB software programming,and then the curve of flash radiation temperature with time was obtained by ratio method.Based on this,the spatial evolution model of flash radiation near the impact point is established.Based on the predecessors’ study of hypervelocity impact flash radiation influence factors,design different projectile impact velocity and differentimpact angle and the different probe location of hypervelocity impact experiment.The research on the flash radiation characteristics of hypervelocity impact has important application value in missile interception,astrophysics and deep space exploration.The experimental results are as follows:(1)By analyzing impact parameters as well as test results,the maximum flash radiation intensity around the impact point in the hypervelocity impact is directly related to the projectile impact velocity,impact angle and detection position.With the given impact angle and detection location,the maximum flash radiation intensity obtained by MATLAB,increases with the projectile impact velocity,and with increasing impact velocity,the amplitude of increment shows a decreasing tendency;with the similar impact velocity and detection locatione,the maximum flash radiation intensity decreases with the increasing impact angles,and the amplitude of decrease shows a decreasing trend.(2)By analyzing impact parameters as well as test results,the maximum flash radiation temperature around the impact point in the hypervelocity impact is directly related to the projectile impact velocity,impact angle and detection position.With the given impact angle and detection location,the maximum flash radiation temperature obtained through the 4-channel ratio method,increases with the projectile impact velocity,and with increasing impact velocity,the amplitude of increment shows a decreasing tendency;with the similar impact velocity and detection locatione,the maximum flash radiation temperature decreases with the increasing impact angles,and the amplitude of decrease shows a decreasing trend.(3)The spatial evolvement model of flash radiation around the impact point was established based on the maximum flash radiation intensity and temperature obtained usingMATLAB.The results indicate the variation of the impact velocity,impact angle and detection location on the same ellipsoid.The radiation characteristics of the evolution model is different,not only the maximum flash radiation intensity,but also the maximum flash radiation temperature.Under the conditions of consistent impact angle,impact velocity and detection location between the tip of fiber probe and the target,the maximum flash radiation intensity and the maximum flash radiation temperature around the impact point are calculated in the space coordinate where inflation along Y axis is stronger than X axisand Zaxis.(4)Ultra-high-speed camera imaging system was applied to capture the impact process at subsequent time intervals,which is in conjunction with hypervelocity impact theory,verifying the spatial evolvement model around the impact point. |
