【作者】 张成；

【导师】 王浩；

【作者基本信息】 南京理工大学 ， 工程热物理， 2018， 博士

【摘要】 机载布撒器是一种新型低成本精确制导武器,具有防区外发射、模块化、多用途的战术特点,能够快速对机场跑道、集群装甲车辆等较大面积的高价值目标实现精确打击,是各军事大国加紧研究的对象,其中的子弹药抛撒系统对于布撒器应用的可靠性和打击精度至关重要。外燃式气囊抛撒技术以结构简单、成本低、子弹药过载低、分离姿态可控,便于模块化装填等优点,成为布撒器抛撒系统的优先选择。然而,其抛撒气囊一般采用柔性材质(橡胶、芳纶),一方面受材料强度的限制,承压能力较低,另一方面易老化,且对环境因素较为敏感。随着仓储时间的延长,气囊材料性能的弱化将会对整个抛撒系统的可靠性造成影响。针对这一问题和现象本文将设计一种用于抛撒系统的薄壁金属气囊,并通过试验和理论分析的方法对该型气囊在火药燃气的作用下变形膨胀性能及规律展开分析。主要研究工作和成果如下:1.针对目前应用于布撒器抛撒气囊承压强度较低、抗氧化能力较弱的现状,本文根据技术指标的要求及理论计算,提出并设计了一种壁厚仅0.2mm的金属气囊(304不锈钢材料)。依据金属气囊的结构特性,对焊接夹具和工艺进行了设计。为获得薄壁金属气囊的承压强度,并检验结构和焊接工艺设计的合理性,设计并开展了与柔性材质气囊静态承压的对比试验,试验结果表明:薄壁金属气囊气密性良好,与橡胶/芳纶气囊相比,承压强度提高了约50%,重量降低了45%左右。2.在承压试验的基础上,设计并开展了动态抛撒试验,对比分析了曲面和平面两种抛撒方案对结果的影响。试验结果显示,曲面抛撒方案下薄壁金属气囊膨胀高度达到约17.5mm时,短边焊缝处会发生严重的破损,影响抛撒内弹道过程。低装药量条件下子弹药的分离速度仅为10.8m/s,而高装药量条件下分离速度虽达到了14.2m/s,但囊体的破损导致抛撒角速度的产生,影响弹道的稳定性。相对于曲面抛撒方案,平面抛撒方案具有子弹药分离速度更高(17m/s),抛撒弹道更稳定的优点,能够更好的保证布撒器抛撒系统的可靠性和稳定性,保障技术指标的实现。3.鉴于薄壁金属气囊平面抛撒方案下的优良性能,根据试验工况,建立了该方案的内弹道模型和流固耦合模型。其中内弹道模型计算得到的燃气发生器内的燃气状态作为流固耦合模型的入口边界条件,通过分析抛撒过程中囊内流场结构特性的发展与变化规律,气囊的形态变化、囊壁动力学响应,揭示了气囊结构与囊内流场间相互影响的耦合机制,以及子弹药的受力运动特性,弥补了采用单一计算方法(内弹道、结构有限元)的不足。在此基础上,将内弹道模型和流固耦合模型的计算结果与试验值进行对比,验证了模型的正确性。4.以装药量、入口直径、气囊初始面积以及入口偏置为特征参数,通过流固耦合数值仿真的方法,系统的分析了特征参数对抛撒过程和结果的影响,揭示了燃气流场的分布、囊壁动力学特性以及子弹药关键参数(子弹药过载和分离姿态角和速度等)对薄壁金属气囊结构特征参数变化的响应规律,提出了控制子弹药分离时运动状态的有效方法。本文研究内容丰富了机载布撒武器中抛撒系统的类型,为抛撒系统的设计与优化提供理论参考和依据,同时为其它类型子弹药抛撒系统提供了新的设计思路和研究方法。本文的研究成果在对丰富子母战斗部武器系统的研究方法、提高研究效率方面具有重要的意义。更多还原

【Abstract】 Airborne dispenser,with the tactical characteristics of stand-off land attacking,modularization and multi-purpose,is a kind of new low-cost precision-guided weapon systems.In that way,it is able to precisely and quickly strike the high-value targets such as airport and cluster armored vehicles.As a result,military powers intensify the efforts to research it.Especially,the dispersing system in the airborne dispenser is the focus due to its importance to the reliability and precision strike of the weapon system.Base on the advantages of simple structure,low-cost,low overload,easy control of separation posture,convenient modular filling and other features,the external combustion type gasbag dispensing technology has become a priority choice for dispenser dispatching system.However,the gasbag is consisted of flexible material(such as rubber or Kevlar)currently.On one hand,pressure capacity of gasbag is lower because of the limitation of the material’s strength.On the other hand,it is easy to aging,and more sensitive to environmental factors.As the storage time is prolonged,the weakening of the performance of the gasbag will have an impact on the reliability of the entire dispensing system.In order to deal with this problem and phenomenon,a thin-walled metal gasbag is designed in this paper,and the performance of this type of gasbag is verified and analyzed through the test and theoretical methods.The main research work and achievements are as follows:1.In this paper,according to the requirements of the tactical index and the theoretical calculation,a metal gasbag(304 stainless steel)with a wall thickness of only 0.2mm is proposed and designed to response the present situation of lower pressure capacity and poorer oxidation resistance of the bag consisted of flexible material.Based on the structure features of the metal bag,a fixture and welding technology is designed.In order to achieve the pressure capacity of the metal bag and inspect the designation rationality of metal bag’s structure and welding technology,a static pressure bearing test is designed and developed,and a good performance in bearing strength of the metal gasbag is revealed.Its bearing strength is about 50%higher than that of flexible material ones(rubber/Kevlar),while the weight is nearly 45%lighter.2.On the basis of pressure bearing test,a dispersing experiment of metal gasbag is designed and implemented to analyze the different performances of curved and plane dispersing schemes.The results show that the process of dispersing interior ballistics is affected,because serious damage occurs along the short edge welds of metal gasbag when the expansion height of the bag reaches about 17.5mm in the case of curved dispersing scheme.The separation velocity of sub-munitions is only 10.8m/s under the condition of 5g charge weight,while the velocity reaches 14.2m/s under 7g charge condition.Although higher charge weight can contribute to higher separation speed under the condition of curved scheme,angle velocity of the sub-munitions is induced by the damage of metal gasbag,and the stability of dispersing ballistic is also reduced simultaneously.In contrast,the plane dispersing scheme has the advantages both in higher separation speed of sub-munitions(17m/s)and better reliability and stability of dispensing system,which guarantee the realization of technical indicators.3.In view of the excellent performance of thin-walled metal gasbag with the plane scattering scheme,the interior ballistics model and the fluid-structure interaction model(FSI)of plane dispersing scheme are established according to the experimental conditions,where the gas state in the gas generator calculated by the interior ballistics model is considered as the inlet boundary condition of the fluid-solid coupling model.Then the coupling mechanism between the structure of metal gasbag and the internal flow field is revealed by analyzing the development and variation of the characteristics of the flow field in the bag,the shape changes of airbag and the dynamic responses of gasbag’s structure,which supplement the deficiency of the single method(the interior ballistics model or the structural finite element).And the correctness of the two models is verified through the comparison between the results of test and calculation.4.One of the objective of this paper is to provide a help and guidance for further engineering application.Therefore,based on FSI method,the influence of the characteristic parameters which involve the charge weight,inlet diameter,the initial area of airbag and the inlet bias on the dispersion process and the results is analyzed systematically.Then the response of the distribution of gas flow field,dynamic characteristics of the gasbag wall and the crucial kinematics parameters of sub-munitions(such as overload,separation attitude angle and velocity)to the structural parameters change of thin-walled metal gasbag is revealed.Effective methods to control the movement of sub-munitions at separation time are proposed,through the structural optimization design and theoretical analysis of the dispensing system with thin-walled metal gasbag.In summary,the research content in this paper enriches the types of dispersing system used in airborne disperser,and provides theoretical reference and basis for the design and optimization of the dispensing system and also offers a new design idea and research methods for the development of other type ammunition dispensing system.The research achievements in this paper are of great significance to improve the research efficiency of the cluster weapon system.更多还原