高压气体驱动二级轻气炮发射过程的数值模拟方法及应用  

Numerical modeling on the launch process of a two-stage light gas gun using high-pressure gas as the driving source

作　　者：陈履坦 何起光 陈小伟 CHEN Lütan;HE Qiguang;CHEN Xiaowei(School of Mechatronic Engineering,Beijing Institute of Technology,Beijing 100081,China;State Key Laboratory of Explosion Science and Technology,Beijing Institute of Technology,Beijing 100081,China;Advanced Research Institute of Multidisciplinary Science,Beijing Institute of Technology,Beijing 100081,China)

机构地区：[1]北京理工大学机电学院,北京100081 [2]北京理工大学爆炸科学与技术国家重点实验室,北京100081 [3]北京理工大学前沿交叉科学研究院,北京100081

出　　处：《爆炸与冲击》2022年第12期114-130,共17页Explosion and Shock Waves

基　　金：国家自然科学基金(11627901)。

摘　　要：二级轻气炮是一种常见的超高速发射装置,多年来其数值研究大多采用简化一维模型,鲜有三维有限元模型。以14 mm口径高压气体驱动二级轻气炮为研究对象,采用耦合欧拉-拉格朗日(coupled Eulerian-Lagrangian,CEL)算法,根据膜片破裂与否,将二级轻气炮模型解耦为2个分级三维数值模型。为确定实验难以测得的参数(材料摩擦因数和膜片破膜压力),设计正交试验,拟合确定活塞与泵管间摩擦因数为0.82,弹丸与发射管摩擦因数为0.30和膜片破膜压力为11.73 MPa。正交结果表明,摩擦因数对计算结果影响较大,在高压气体驱动二级轻气炮的计算中不应忽略。通过上述方法建立数字化高压气体驱动二级轻气炮,完整复现气炮发射过程,计算的弹丸终速与实验结果吻合度高。选取验证工况详细分析了气炮发射过程内流场变化,并呈现关键时刻的压力云图。该气炮简化方法、分级思想和关键参数确认方法可推广应用于固体发射药驱动、爆轰驱动等其他驱动形式的二级/多级轻气炮。A two-stage light gas gun is a common hypervelocity launcher.Over the years,most researchers adopted simplified one-dimensional models and rarely used three-dimensional finite element models.This paper used the coupled Eulerian-Lagrangian algorithm to calculate the gas-driven hydrodynamic field in a 14-mm-caliber two-stage light gas gun.The twostage light gas gun was decoupled into two three-dimensional numerical models according to whether the diaphragm was broken.A three-factor four-level orthogonal test was carried out to get the material friction coefficient and the broken diaphragm pressure,which were difficult to measure in experiments.The ordinary least square method was used to calculate the orthogonal test data.The friction coefficient between the piston and the pump tube was 0.82,the friction coefficient between the projectile and the launch tube was 0.30,and the broken diaphragm pressure was 11.73 MPa.The orthogonal test showed that the friction coefficient and the broken diaphragm pressure significantly influenced the calculation results.The friction could not be ignored in calculating the launch process of the two-stage light gas gun.So keeping the gun body clean was necessary to improve the projectile velocity.The numerical model for the two-stage light gas gun was established based on the method mentioned above,which completely reproduced the launch process of the gas gun,and visually represented the change of the flow field.The velocities of the projectile were numerically obtained by the established model,which were highly consistent with the experimental results.In addition,the verification condition was selected to analyze the change of the flow field,and the pressure nephograms at the critical moments were given.It should be noted that the velocity range of the projectile was 3-5 km/s.The method is fully applicable for the projectile velocity below 3 km/s and is generalizable for the higher projectile velocity.The gas gun simplification method,grading idea and key parameter confirmation method

关 键 词：二级轻气炮 正交试验 分级三维数值模型 耦合欧拉-拉格朗日算法 

分 类 号：O313.4[理学—一般力学与力学基础]