摘要
采用大涡模拟研究了凹壁面切向射流作用下近壁面圆球型颗粒对流体流动特性的影响,模拟获得的尾涡结果与实验示踪剂图像吻合较好。研究了颗粒尾流的涡旋结构及其演变过程,考察了雷诺数Re=700~10000时颗粒周围速度、涡量及流线变化。结果表明,随着雷诺数增加,颗粒的影响区域涡量增强,涡量的峰值始终出现在颗粒迎流面,颗粒后侧的回流区显著收缩。Re≥2000时在射流展向颗粒后侧存在两个尾涡,流体的切向速率和涡量均发生周期性波动。对颗粒的升力和阻力进行了监控,Re=2000时旋涡脱落频率对应的斯特劳哈尔数St=0.000854,升力功率谱中峰值对应的St=0.00152;Re=10000时阻力功率谱没有发现峰值,升力功率谱中峰值对应的St=0.00874。
Large eddy simulation was used to simulate the influence of spherical particles near the wall on fluid flow characteristics under the action of tangential jets on the concave-wall.The simulated wake vortex results were in good agreement with the experimental tracer image.The vortex structure and its evolution process of particle wake with particle diameter dp=4 mm and radius of curvature of concave wall R=200 mm were studied.The changes of velocity,vorticity,and streamline around the particle were investigated at Reynolds number Re=700~10000.The results showed that the vorticity in the influence area of particles increased,the peak value of vorticity always appeared on the upstream surface of particles,and the recirculation zone behind the particles shrank significantly with the increase of Reynolds number.When Re=700,there was only one wake vortex behind the particle along the concave wall jet spanwise.When Re≥2000,there were two wake vortices behind particles along the concave wall jet spanwise,and the tangential velocity and vorticity of the fluid fluctuated periodically.The particle lift and resistance were monitored.There was the vortex shedding frequency at Strouhal number St=0.000854 when Re=2000,and the peak value of the lift power spectrum occurred at St=0.00152.The frequency peak corresponding to the boundary layer and wake instability was not found in the drag power spectrum when Re=10000,and the peak of the lift power spectrum occurred at St=0.00874.The particle wake had a great influence on the flow field.The analysis of the particle wake characteristics in the tangential jet on the concave wall was an in-depth study of the liquid-solid two phase separation mechanism.It provided the theory for the characteristics of single particle wake vortex in the process of heterogeneous separation of the tangential jet from concave wall.
作者
张静
侯文浩
周承昊
田志国
龚斌
Jing ZHANG;Wenhao HOU;Chenghao ZHOU;Zhiguo TIAN;Bin GONG(School of Mechanical and Power Engineering,Shenyang University of Chemical Technology,Shenyang,Liaoning 110142,China)
出处
《过程工程学报》
CAS
CSCD
北大核心
2023年第11期1497-1505,共9页
The Chinese Journal of Process Engineering
基金
辽宁省应用基础研究计划项目(编号:2022JH2/101300077)
辽宁省教育厅自然科学基础项目(编号:LJ2020016)。
关键词
凹壁面切向射流
大涡模拟
尾流
旋涡
功率谱
concave-wall tangential jet
large eddy simulation
wake
vortex
power spectrum
