腔径比对亥姆赫兹自振射流性能影响  

Numerical investigation of cavity diameter ratio influence on Helmholtz oscillation waterjet

作　　者：方珍龙 康勇[1,2] 王晓川[1,2] 刘文川[1,2] 李登[1,2] 周勇祥[1,2] 

机构地区：[1]武汉大学动力与机械学院,湖北武汉430072 [2]水射流理论与新技术湖北省重点实验室,湖北武汉430072

出　　处：《浙江大学学报（工学版）》2016年第11期2100-2106,2157,共8页Journal of Zhejiang University：Engineering Science

基　　金：国家"973"重点基础研究发展计划资助项目(2014CB239203);国家自然科学基金资助项目(51474158);教育部新世纪优秀人才支持计划资助项目(NCET-12-0424)

摘　　要：为了提高亥姆赫兹式自振射流的工作能力,采用大涡模拟对自振射流流动特性进行研究,通过实验测试喷嘴出口压力脉动验证了数值模拟的准确性.对4种腔径比的自振喷嘴模型在3种雷诺数下的瞬态流场进行模拟,分析Q准则数下拟序结构涡的运动特性,揭示轴心速度衰减及出口断面速度分布与射流集束性及腔室能量耗散的关系,比较分析振荡幅值对射流脉冲性能的影响.结论表明,大涡模拟可以准确预测自激振荡射流瞬态流场及流动特性,亥姆赫兹腔使均匀来流变得紊乱,涡尺度增大,腔室内能量耗散增大,且腔径比对自振射流影响较大.Large eddy simulation（LES） was conducted to investigate its flow characteristics in order to improve the working ability of Helmholtz self -excited oscillation pulsed je t（SOPJ）. The reliability of numerical simulation was verified by experimentally measuring the pulsating pressures at nozzle outlet. The results of four models of different cavity diameter ratios were analyzed under three Reynolds numbers. The vortex motion characteristics were investigated by considering the coherent structrue （Q criteria number）. The fluidic beam concentration and energy dissipation in the chamber were evaluated based on the axial velocity attenuation and velocity distribution profiles. The pulse performance was analyzed according to the oscillation amplitude. Results show that LES can reasonably simulate the unsteady flow field of SOPJ. Helmholtz cavity turns uniform flow into turbulence flow, the scale of verity increases, and the energy dissipation inside the cavity can be intensified. The ratio of cavity diameter to jet diameter is of great significance.

关 键 词：自振射流 腔径比 大涡模拟 拟序结构 

分 类 号：TG137[一般工业技术—材料科学与工程]