渐扩边界形状对双股燃气射流扩展特性影响的实验研究

摘要

为了研究控制整装式液体发射药火炮内弹道稳定性的方法,设计了不同结构的多级圆柱渐扩型观察室,采用数字高速录像系统,观察并讨论了双股燃气射流在液体药模拟工质中的扩展过程,对比了不同的渐扩结构、喷射压力、喷孔中心间距、喷嘴直径等参数对双股燃气射流在液体工质中扩展特性的影响.实验结果表明,多级渐扩型结构能够有效控制气液的湍流掺混特性,且喷射压力较大时,双股燃气射流沿轴向扩展较为迅速,气液的湍流掺混也较剧烈；而喷孔间距较大时,双股燃气射流的轴向扩展速度相对较小,射流沿着径向扩展较为明显,双股燃气射流最终发生汇聚的时间也较晚.%In order to investigate the means of interior ballistic stability in bulk-loaded propellant guns,the different structures of cylindrical stepped-wall observation chambers were designed.The expansion processes of twin gas jets in liquid were studied by high-speed photographic system.The influences of stepped-wall configuration,injection pressure,dual-orifice interval and nozzle diameter on twin jets were discussed.The experimental results show that a useful approach of improving the mixture characteristics of twin gas jets and liquid medium can be achieved by using a cylindrical stepped-wall observation chamber.The higher is the injection pressure,the faster is the expansion of twin gas jets along the axial direction,and the turbulent mixture of twin combustiongas jets in liquid is very intense.The bigger is the dual-orifice interval,the relatively smaller is the expansion velocity of twin gas jets along axial direction,and the later is the coalescence time of twin gas jets.