自激吸气式脉冲射流装置机理的试验和理论研究  

Experimental and theoretical researches on mechanism of self-excited aspiration pulse jet device

作　　者：叶飞 刘新阳[2] 赵礼 陈豪[2] YE Fei;LIU Xinyang;ZHAO Li;CHEN Hao(Zhejiang Water Conservancy and Hydropower Engineering Quality and Safety Management Center,Hangzhou 310012,China;North China University of Water Resources and Hydropower,Zhengzhou 450045,China)

机构地区：[1]浙江省水利水电工程质量与安全管理中心,杭州310012 [2]华北水利水电大学,郑州450045

出　　处：《流体机械》2023年第3期1-7,11,共8页Fluid Machinery

基　　金：国家自然科学基金项目(51309099);浙江省水利科技重点项目(RC2001)。

摘　　要：为了揭示自激吸气式脉冲射流装置的脉冲产生机理,通过试验获取了装置典型测点压力、靶心冲击压力的时间变化过程和内部水气流动图像,分析了工作压力1.4~1.8 MPa和围压0~0.15 MPa下冲击压力的平均值、脉冲频率和脉冲效果,并结合水气两相流理论研究了装置内部的水气流动结构和水气流动过程。结果表明,围压不变和工作压力越高,冲击压力平均值越大,围压0.1 MPa时,增加幅度为51%;工作压力不变和围压越高,冲击压力平均值越小,工作压力1.8 MPa时,降低幅度为63%;不同工作压力和围压的冲击压力脉冲频率变化不大,在0.5~1.0 Hz之间,但工作压力越高或围压越低,脉冲效果越好;装置内部的碰撞体附近和射流核两侧为亚声速水气流动,下喷嘴入口为超声速水气流动;装置在内部负压区域形成了泡状水气涡团,吸气量、碰撞体测点压力和冲击压力的时间变化过程与典型时间水气涡团的旋转速度和气泡直径之间具有明显的相互影响关系。In order to reveal the pulse generation mechanism of self-excited aspiration pulse jet device,the time-varying process of the pressure at typical measuring point,the impact pressure of target center and internal water-gas flow image were obtained by test.The average-value,pulse frequency and pulse effect of the impact pressure under different working pressure of 1.4~1.8 MPa and confining pressure of 0~0.15 MPa were analyzed.The internal flow structure and process of the device were studied in combination with water gas two-phase flow theory.The results show that when the confining pressure is constant and the working pressure is higher,the average-value of impact pressure is larger.When the confining pressure is 0.1 MPa,the increase amplitude is 51%.When the working pressure is constant and the confining pressure is higher,the average-value of the impact pressure is smaller.When the working pressure is 1.8 MPa,the reduction amplitude is 63%.The pulse frequency varies little with different working pressures and confining pressures,ranging from 0.5~1.0 Hz,but the higher the working pressure is or the lower the confining pressure is,the better pulse effect of the impact pressure is.Inside the device,subsonic water-gas flow is observed near the colliding body and on both sides of the jet core,and supersonic water-gas flow is observed at the inlet of downstream nozzle.Bubbly flow water-gas vortices are formed in the internal negative pressure area of the device,and there is an obvious interaction relationship between the time-varying process of the aspiration capacity,the colliding body measuring point pressure and the impact pressure,and the water-gas vortex rotating velocity and bubble diameter at typical times.

关 键 词：自激吸气式 脉冲射流 冲击压力 水气涡团 机理 

分 类 号：TH12[机械工程—机械设计及理论] TK72[动力工程及工程热物理—流体机械及工程]