淹没磨料射流涡旋特性大涡模拟及研究  

Vortex characteristics of submerged abrasive jet with large eddy simulation

作　　者：张欣玮[1,2] 卢义玉[1,2] 周哲[1,2] 汤积仁[1,2] 

机构地区：[1]重庆大学煤矿灾害动力学与控制国家重点实验室,重庆400030 [2]重庆大学复杂煤气层瓦斯抽采国家地方联合工程实验室,重庆400030

出　　处：《振动与冲击》2016年第19期1-6,共6页Journal of Vibration and Shock

基　　金：国家重点基础研究发展计划(2014CB239206);国家自然科学基金青年基金项目(51404045);长江学者和创新团队发展计划(IRT13043)

摘　　要：基于涡运动理论,采用固-液两相大涡模拟方法模拟了淹没磨料射流的涡量场,分析了涡旋扩散机理与卷吸特性以及磨料随涡运动在射流中的混合分布规律.流场剪切层中涡旋呈对称分布,沿轴线方向涡量呈指数衰减,衰减到最小值两侧涡旋混合成紊流混合区,而等速核内涡量几乎为零.相比于纯水射流,磨料的存在使得射流涡运动减弱,涡旋扩散角减小约50%,等速核增长约30%,减少了能量耗散.磨料在射流束内部时,受涡旋影响,趋向分布于高应变率、低涡量区,在涡旋下游侧磨料浓度最高.同时模拟研究了磨料参数对涡量场的影响规律,结果表明：磨料参数基本不影响扩散角（14.1°-15.1°）、等速核长度,卷吸能力随磨料浓度、粒径、密度的升高均呈现小幅度地降低,磨料密度对其影响程度最大,磨料粒径的影响最不明显.Based on the theory of vortex motion, the vorticity field of submerged abrasive jet were simulated using the two-phase large eddy simulation method. The mechanism of eddy diffusion and entrainment were analyzed, the abrasive distribution law with vortex movement in the jet was acquired. It was shown that the vortex distribution of the shear layer in the flow field is symmetrical; vorticity at both sides of the vortex mixing presents an exponential attenuation to the minimum value, the vortex mixing forms a turbulent mixing zone; the potential core is irrotational everywhere; compared with pure water jet, the existence of abrasive makes vortex motion abate, the eddy diffusion angle decreases by about 50% and potential core grows by about 30% ; the abrasive affected by vortex tends to be distributed in the area of high strain rate and low vorticity; abrasive concentrates in the downstream side of vortex. The influence law of abrasive parameters on the vorticity field was also studied with simulation. The results showed that the diffusion angle （14.10？15.10） and the potential core length basically remain unchanged with variation of abrasive parameters; the entrainment ability decreases slightly with increase in abrasive concentration, particle size and density.

关 键 词：淹没射流 磨料 涡旋 大涡模拟 

分 类 号：TE319[石油与天然气工程—油气田开发工程]