高降压速率下复合底排药剂瞬变燃烧特性研究

为了提高底排弹出炮口时底排装置的工作稳定性与一致性,采用半密闭爆发器模拟炮口工况,借助高速录像系统,开展了高降压速率下复合底排药剂瞬变燃烧特性的试验研究。实验中,半密闭爆发器燃烧室压力控制在20～90MPa范围内,降压速率为1.2×103～6×103MPa.s-1。实验表明,因破孔压力及降压速率不同,复合底排药剂燃烧行为分为自行稳定复燃、永久熄灭和临界状态三种情况。决定这些行为的关键因素是降压速率与降压前的初始压力。分析表明,在火炮发射条件下,底部排气弹出膛口时,复合底排药剂燃烧环境恰好处于永久熄灭/熄灭后再复燃的临界状态。

Combustion of Composite Base Bleed Charge Under Rapid Depressurization

To improve the stability and consistency of base bleed unit while the projectile was out of the gun muzzle, the characteristics of transient combustion of composite base bleed charge was studied by using a semi-closed bomb to simulate a abrupt depressurization and a high speed digital video camera to record the phenomena of combustion. The pressure of combustion chamber in semi-closed bomb was controlled to vary from 20 MPa to 90 MPa, and the velocity of depressurization from 1.2×10³ MPa·s^-1 to 6×10³ MPa·s^-1. The results show that there are three kinds of combustion characteristics, e.g. reignition,extinguishment and critical case, when pressure and depressurization rate change. The depressurization rate and the pressure before depressurization are key factors influencing the combustion of base bleed charge. The analysis indicates that the cornbustion of base bleed charge is in the critical zone between extinguishment and reignition when the base bleed projectile is just out of the gun muzzle.