【摘要】 为研究强冲击状态下混入少量空气的甲烷气体的冲击状态参数,利用二级轻气炮加载技术,使加速到5 km/s的钨合金飞片撞击封装有常态下空气混入量依次为零(纯甲烷气体)、1%、5%、10%的甲烷-空气混合气体铝靶。采用六通道瞬态光学高温计记录冲击压缩气体的光辐射历程曲线,得到了相同初始条件下4种不同比例混合气体的冲击状态参数。结果表明,在强冲击压缩下,混合气体的冲击温度随着空气混入比例的增大而增高,冲击波后混合气体存在非平衡辐射过程。采用Saha电离平衡方程,对空气混入量为10%的混合气体的电离度进行了估算。结果表明,常态下空气含量Cair≤10%的甲烷-空气混合气体具有电探针保护能力。更多还原

【Abstract】 To study the state parameters of methane-air mixture under shock compression,Aluminum target chamber filled with methane-air mixture were impacted by tungsten alloy projectiles.Projectiles were accelerated to about 5 km/s using a two-stage light gas gun.Methane-air mixture with different air ratioes of 0,1%,5%,and 10% were tested,respectively.The radiance signals from shocked methane-air gases were recorded by an instantaneous pyrometer system.The Hugoniot data of four mixed ratio gases were obtained.The experimental results indicated that the shock temperatures of mixtures increase with rising of the air mixed ratio.The mixtures emitted non-equilibrium thermal radiation in shock downstream.The ionization of methane-air gas with 10% air mixed ratio is calculated by Saha ionization function.Calculated results indicated that methane-air mixed gases with an air mixed ratio less than 10% doesn’t ionize,and can protect pins effectively.更多还原