摘要
底部排气弹射程和纵向密集度与点火具的工作性能密切相关。采用高速录像系统和红外热像仪研究了大气环境中,镁/聚四氟乙烯(MT)(Mg/PTFE 45/55、Mg/PTFE 55/45、Mg/PTFE 61/39)、硝酸钡(Ba(NO_3)_2)和氢化锆/氧化铅(ZrH_2/PbO_2 40/60)五种点火药剂在不同点火具孔径(6.5,8mm)下的燃烧扩展特性,并测得七种点火具的火焰温度场分布。在实验基础上,以基于内节点的有限体积法对MT点火具的燃烧射流场进行三维数值模拟,分析了不同MT质量比和点火具孔径下点火具在大气中的燃烧特性参数分布规律。实验和数值结果表明:ZrH_2/PbO_2点火具会破坏底排推进剂的"平行层"燃烧规律;提出以点火面积有效因子表示推进剂点火面积的有效程度,并结合点燃时间综合评估点火具的点火性能,发现MT质量比为61∶39,孔径为8mm的点火具性能最优;点火具火焰最高温度区均位于喷孔的势流核上方;镁质量分数为0.45~0.61时,镁含量越小,MT点火具燃烧场中火焰温度越高,镁含量一定,点火具孔径为6.5,8mm时,较大孔径有较强烈燃烧场热对流,较高中心轴向温度,较大温度梯度。
The range and longitudinal intensity of base-bleed projectile are closely related to the working performance of igniter.The combustion expansion characteristics of igniter with different orifice diameters(6.5,8mm)for five kinds of ignition agents,magnesium/polytetrafluoroethylene(MT)(Mg/PTFE45/55,Mg/PTFE55/45,Mg/PTFE61/39),barium nitrate(Ba(NO3)2)and zirconium hydride/lead oxide(ZrH2/PbO240/60),were investigated in the atmospheric environment by using high-speed camera system and infrared thermal imager and then the flame temperature field distribution of seven kinds of igniters was measured.On the basis of experiment,the cell-centered finite volume method based on internal nodes was applied to three-dimensional numerical simulation of the combustion jet field of MT igniter.The distribution rule of combustion characteristic parameters of the igniter in the atmosphere under different mass ratios of MT and orifice diameters of the igniter was analyzed.The experimental and numerical results show that ZrH2/PbO2igniter will destroy the“parallel layer”combustion law of base bleed propellant.The ignition are aeffective factor is proposed to represent the significant degree of the propellant ignition area,and is combined with the ignition time to synthetically evaluate the ignition performance of the igniter.It is found that the MT igniter with mass ratio of61∶39and orifice diameter of8mm is the best.The maximum flame temperature region of igniter is located above the potential core of the nozzle.The smaller the magnesium content in the range of0.45-0.61is,the higher the flame temperature in the combustion field of the MT igniter.When the magnesium content is constant and the orifice diameter of igniter is6.5mm and8mm,the larger orifice diameter has the stronger heat convection in the combustion field,the higher center axial temperature and the greater temperature gradient.
作者
马龙泽
余永刚
MA Long-ze;YU Yong-gang(School of Energy and Power Engineering,Nanjing University of Science and Technology,Nanjing 210094,China)
出处
《含能材料》
EI
CAS
CSCD
北大核心
2017年第12期982-990,共9页
Chinese Journal of Energetic Materials
基金
国家自然科学基金资助(51176076)
关键词
底排点火具
燃烧射流
扩展特性
点火性能
有限体积法
base-bleed igniter
combustion jet
expansion characteristics
ignitionpe rformance
finitevolumemethod
