射流声阻抗差异对爆轰管口流场结构影响的数值模拟研究  

Numerical Simulation Study on the Influence of Acoustic Impedance Difference of Jet on the Flow Field Structure of Detonation Tube Exit

作　　者：范振华 黄孝龙[1] 侯子伟 李宁[1] 康杨[1] 翁春生[1] FAN Zhenhua;HUANG Xiaolong;HOU Ziwei;LI Ning;KANG Yang;WENG Chunsheng(National Key Laboratory of Transient Physics,Nanjing University of Science and Technology,Nanjing 210094,China;Beijing System Design Institute of Electro-mechanic Engineering,Beijing 100854,China)

机构地区：[1]南京理工大学瞬态物理国家重点实验室,江苏南京210094 [2]北京机电工程总体设计部,北京100854

出　　处：《弹道学报》2024年第4期11-20,共10页Journal of Ballistics

基　　金：国家自然科学基金青年基金项目(12302439);瞬态物理重点实验室基金(6142604200202);江苏省自然科学基金青年基金项目(BK20190439)。

摘　　要：为研究射流环境中声阻抗差异对爆轰管口流场结构的影响规律,建立爆轰管内外流场的轴对称模型,采用OpenFoam平台的rhoReactingCentralFoam求解器进行耦合求解。通过在管口处构建氩气、氢气和空气混合物、氦气3种自由射流区域,结合管口处是静止空气时的仿真结果,分析了管内外介质声阻抗差异对爆轰流场结构的影响。结果表明:氩气射流和静止空气会使爆轰波溢出管外时,在声阻抗间断面处形成反射激波;氦气射流会使爆轰波溢出管外时,在声阻抗间断面处形成反射稀疏波;氢气和空气混合物射流则对该过程无影响。在氩气射流和静止空气中形成的马赫盘减小到基本消失,滑移线和其后的超音速区域在马赫盘附近相遇;氢气和空气混合物射流和氦气射流中的马赫盘减小后仍保持一定大小,滑移线和其后的超音速区会在离马赫盘较远的地方相遇。自由射流与可爆混合物的声阻抗差异会使前导激波波阵面发生变形并改变其指向性。氩气射流中的前导激波阵面在靠近中心轴线处弯曲程度减小,静止空气中的前导激波大致呈现球面波的形态,氢气和空气混合物射流与氦气射流中的前导激波阵面发生凸起。In order to study the influence of acoustic impedance difference on the flow field structure of detonation tube exit in jet environment,an axisymmetric model of the flow field inside and outside the detonation tube was established.The rhoReactingCentralFoam solver of the OpenFoam platform was used to couple the flow field inside and outside the detonation tube.Three free jet regions of argon,hydrogen and air mixture,and helium were constructed outside the tube.Combining with the simulation results of the static air outside the tube,the influence of the acoustic impedance difference of the medium inside and outside the tube on the detonation flow field structure was analyzed.The results show that the argon jet and the static air will form a reflected shock wave on the acoustic impedance discontinuity surface when the detonation wave overflows outside the tube.The helium jet forms a reflected rarefaction wave on the acoustic impedance discontinuity surface when the detonation wave overflows outside the tube.The hydrogen and air mixture jet has no effect on the process.The Mach disk formed in the argon jet and the static air is reduced to almost disappear.The slip line and the subsequent supersonic region encounter near the Mach disk.The Mach disks in the hydrogen-air mixture jet and the helium jet remain a certain size after decreasing.The slip line and the subsequent supersonic region encounter far away from the Mach disk.The acoustic impedance difference between the free jet and the explosive mixture causes the leading shock wave to deform and change its directivity.The curvature of the leading shock wave near the central axis in an argon jet decreases,and the leading shock wave in still air roughly presents a spherical wave shape.The leading shock wave in a hydrogen air mixture jet and a helium jet protrudes.

关 键 词：OPENFOAM 爆轰 管口流场 射流声阻抗 流场结构 

分 类 号：O382.1[理学—流体力学] TJ011.1[理学—力学]