边界形状对4股燃气射流扩展稳定性影响的数值模拟  

Numerical Simulation of the Influence of Boundary Shape on the Expansion Stability of Four Combustion-gas Jets

作　　者：冯博声 薛晓春[1] FENG Bo-sheng;XUE Xiao-chun(School of Energy and Power Engineering,Nanjing University of Science and Technology,Nanjing 210094,Jiangsu,China)

机构地区：[1]南京理工大学能源与动力工程学院,江苏南京210094

出　　处：《兵工学报》2018年第9期1692-1700,共9页Acta Armamentarii

基　　金：国家自然科学基金项目(51506096);江苏省自然科学基金项目(BK20150765)

摘　　要：为研究提高整装式液体发射药火炮燃烧稳定性的方法,从充液室结构出发,分析了冷态条件下边界形状对4股燃气射流扩展稳定性的影响。采用高速数字摄像系统,记录了4股燃气射流在5级圆柱渐扩型观察室中扩展过程。在此基础上,建立了气体与液体相互作用的三维非稳态数理模型,模拟了4股燃气射流在5级圆柱渐扩型、圆锥型和圆柱型观察室中扩展过程,获得了射流场三维两相分布图、压力和温度分布图。研究结果表明:4股燃气射流在5级圆柱渐扩型观察室中轴向位移的模拟值与实验结果较吻合;圆柱渐扩型和圆锥型观察室都可以增强燃气射流的径向扩展,有效抑制Taylor空腔与Helmholtz不稳定效应的正反馈机制;圆柱渐扩型由于台阶逐渐诱导作用,近喷孔处温度场无剧烈脉动,射流扩展更加稳定。The influence of boundary shape on the expansion stability of four combustion-gas jets under cold conditions is discussed to study an approach to improve the combustion stability of bulk-loaded liquid propellant gun.High-speed digital video recording system is used to record the expansion process of four combustion-gas jets in a five-stage cylindrical stepped-wall type observation chamber.On this basis,a three-dimensional unsteady mathematical model of gas-liquid interaction is established to simulate the expansion processes of four combustion-gas jets in a five-stage cylindrical stepped-wall type,conical and cylindrical observation chambers.The three-dimensional two-phase distribution chart,pressure and temperature distribution chart of jet field were obtained.The results show that the simulated results of axial displacements of four combustion-gas jets in the five-stage cylindrical stepped-wall type chamber coincide well with the experimental results.Both the cylindrical stepped-wall type chamber and the conical chamber can enhance the radial expansion of combustion-gas jet and effectively suppress Taylor cavity and Helmholtz instability;due to gradual induction of stepped-wall in the cylindrical stepped-wall type chamber,the temperature field near the nozzle has no severe pulsation and the jet expansion is more stable.

关 键 词：4股燃气射流 Taylor扩展特性 湍流掺混 数值模拟 

分 类 号：TJ012.15[兵器科学与技术—兵器发射理论与技术]