水下超音速气体射流胀鼓和回击的关联性研究  

EXPERIMENTS ON THE RELATIONSHIP BETWEEN BULGING AND BACK-ATTACK OF SUBMERGED SUPERSONIC GAS JETS

作　　者：施红辉[1] 郭强[1] 王超[1] 王晓刚[1] 章利特[1] 董若凌[1] 贾会霞[1] 

机构地区：[1]浙江理工大学机械与自动控制学院,杭州310018

出　　处：《力学学报》2010年第6期1206-1210,共5页Chinese Journal of Theoretical and Applied Mechanics

基　　金：国家自然科学基金(10672144);浙江省自然科学基金(Y107073);浙江理工大学科研启动基金资助项目~~

摘　　要：阐述了水下超音速气体射流的实验研究结果.用高速摄影仪实时记录了水下超音速气体射流喷射的状态,清晰地演示了射流气体在上中游流域的演化过程.具体分析了水下高速气体射流的动态不稳定性形貌,并从实时记录的射流照片中统计测量出了胀鼓和回击随机频率.结果发现,胀鼓频率越大,回击频率越大;胀鼓频率随着喷嘴的驻室压力与出口背压的比值增大而增大.通过胀鼓与回击事件前后实验数据的对比分析表明其二者之间存在相关性:胀鼓和回击均由射流内部压力振荡引发并且存在一定的随机性;胀鼓是回击前的能量积聚一个前征和表现,当胀鼓的振荡即能量积聚到一定程度后,引发回击.The paper presents an experimental study on dynamic instability of submerged supersonic gas jets.The gas-jet flow patterns are recorded at real time by a high-speed camera.The development process of supersonic and subsonic gas jets and the process of the unstable flow pattern are visualized clearly.The patterns of the unstable jet flow are analyzed in detail.The frequencies of bulging and back-attack of the jet are calculated from the experiment data.The experimental results indicate that the frequency of the back-attack increases with increasing the bulging frequency,and the frequency of the bulging increases with increasing the stagnation pressure ratio P_0/P_b.Comparison of the data from the two kind of unstable patterns indicates a certain relevance between bulging and back-attack：Both the bulging and back-attack are all initiated by pressure oscillation inside of the gas jets and have a strong randomness,and the bulging is a kind of representation of energy storage before back-attack happens.In addition,when the energy storage gets to a certain limit,a back-attack event will be occurring.

关 键 词：水下超音速气体 射流 流动不稳定性 胀鼓 回击 相关性分析 

分 类 号：O358[理学—流体力学]