单模块装药点火燃烧过程中端盖破裂形态对药粒散布的影响

Effect of Rupture Form of End Cover on Grain Dispersion durning Ignition and Combustion of Single Module Charge

为了探究模块药盒在点火燃烧过程中端盖的破裂形态对药粒散布特性的影响,基于CFD-DEM方法,建立三维非稳态气固两相流模型,对模块药盒端盖不同破孔方式下发射药粒的堆积分布进行了数值模拟。模拟结果表明,药室内药粒的最终堆积分布均依次呈缓坡堆积、水平堆积及陡坡堆积的组合分布,但各形态的形状特征参数不同。当初始破裂区域所对应的扇形圆心角从0°增为120°时,缓坡和水平堆积的轴向长度由269mm增至320mm,水平堆积部分的平均药粒厚度由18.1mm增至22.8mm,陡坡状药粒堆积占比由70.3%减少为65.1%。端盖下半部分区域较上半部分区域先破孔,缓坡和水平堆积长度更长且平均药粒堆积厚度更厚,陡坡状药粒堆积占比更少。端盖左右两侧先破孔,缓坡和水平堆积的轴向长度、水平堆积部分的平均药粒厚度、陡坡状药粒堆积占比均基本相同,先破孔的一侧陡坡堆积部分药粒数占比会略微低于后打开的一侧。

To investigate the effect of the rupture form of end cap of the modular cartridge on the dispersion characteristics of propellant grains during the ignition and flame spreading processes,a 3D unsteady state gas-solid two-phase flow model was established based on computational fluid dynamics-discrete element method(CFD-DEM),and the dispersion characteristics of propellant grains was numerically simulated under different perforation modes of end cap of the modular cartridge.The simulation results show that the propellant grains presents a combined accumulation form with gentle slope section,plain section and steep slope section with different accumulation parameters from the primer side to the pressure control diaphragm side.With the circular sector increased from 60°to 120°,the axial length of gentle slope and horizontal accumulation increases from 269mm to 320mm,the average particle thickness of horizontal accumulation increases from 18.1mm to 22.8mm,and the proportion of steep slope particle accumulation decreases from 70.3%to 65.1%.The broken of the end cap at the under part contributes to more distribution of grains at gentle slope section and plain section along the axial direction,and less accumulation at steep slope section.The broken of end cap at left side and right side leads to almost the same distribution of grains along the axial direction in terms of axial length,thickness and proportion of accumulation at steep slope section.While the proportion of accumulation of propellant grains at steep slope is slightly lower when the cap broken on one side.