微细圆管中B/KNO_3燃烧特性分析

为了解微细圆管中点火药的燃烧特性,采用高速摄影技术对微细圆管中B/KNO3的燃烧进行实验研究,结果表明:管壁热损失和管道阻力是影响微细圆管中B/KNO3燃烧稳定性的主要因素。圆管内径越小,管壁热损失和管道阻力越大,燃烧越不稳定。B/KNO3在内径1.0～2.0 mm石英管中稳定燃烧、燃速变化微弱。燃烧室压强为0.1～4.0 MPa时,B/KNO3燃速随压强增加,但并不符合燃速指数规律。当石英管内径减至0.5 mm时,燃烧不稳定,燃速随时间延长而变大;圆管内径进一步减小,产生击穿现象导致火焰熄灭。研究还表明在一定壁厚范围内,燃速反比于壁厚。

Combustion Characteristics of B/KNO3 in Microscale Tube

To understand combustion characteristics of igniter in microscale tube,B/KNO₃ combustion in microscale tube were obtained from high-speed photography. Results show that wall heat loss and tube resistance are the main affecting factors for combustion stability. Combustion is stable in 1.0-2.0 mm quartz tube,and B/KNO₃ burning rate varies weakly. B/KNO₃ burning rate is proportional to combustion chamber pressure among 0.1-4 MPa,however,it is not consistent with exponent law. Combustion is unstable when the inner diameter of quartz tube is decreased to 0.5 mm,and the burning rate is increased with increasing of time. When the inner diameter of quartz tube is reduced further,breakdown phenomenon is produced and combustion quenching is caused. In addition,B/KNO₃ burning rate is in inverse proportion to wall thickness in the certain extent.