基于VLES模型的振动圆柱数值模拟  

Numerical Simulation of Flow Over Oscillating Cylinders Based on a VLES Model

作　　者：刘小民[1] 熊仲营 LIU Xiao-Min;XIONG Zhong-Ying(School of Energy and Power Engineering,Xi'an Jiaotong University,Xi'an 710049,China)

机构地区：[1]西安交通大学能源与动力工程学院,西安710049

出　　处：《工程热物理学报》2021年第1期89-95,共7页Journal of Engineering Thermophysics

基　　金：装备预研领域基金项目(No.61402070302)。

摘　　要：本文将一种VLES(Very Large Eddy Simulation)模型引入到动网格数值计算中,并验证了VLES模型用于模拟类似振动圆柱绕流的动边界问题的有效性。数值求解了不同振幅和频率下非稳态振动圆柱绕流问题。研究表明:随着振幅和激励频率的增加,绕圆柱流动涡脱离形式从2S模式转换到2P0模式,再到P+S模式。在高振幅和激励频率比fe/fs=0.95时,涡脱离形式却表现为2P0模式到P+S模式的过渡状态,振动圆柱在上升或下降过程中涡的脱离造成在每个周期升力曲线的左右侧发生不规则的"跳动"现象,尽管脱落涡可能为涡对或者单涡.In this paper,a VLES(Very Large Eddy Simulation) model is introduced into the dynamic grid technique and verified to be well used to simulate the dynamic boundary of oscillating cylinders.A series of numerical simulations,including three cylindrical oscillation amplitude A/D=0.5,1,1.5,and three kinds of oscillation frequency fe/fs=0.5,0.75,0.95,are carried out to explore the transient flow over oscillating cylinders.Moreover,it is concluded that in larger amplitude and higher oscillating frequency,the wake formation changes from the 2 S model to the 2 P0 model,further to the P+S mode.When A/D=1.5 and fe/fs=0.95,the mode of vortex shedding is in a transitional state from a 2 P0 mode to a P+S mode.The shedding of the vortices of the oscillating cylinder in the process of the upward or downward oscillation causes irregular jumping phenomenon on the left and right sides of the temporal evolution of the lift coefficient in each cycle,although the shedding vortex may be a vortex pair or a single vortex.

关 键 词：VLES方法 振动圆柱 尾迹特征 数值模拟 

分 类 号：TV131[水利工程—水力学及河流动力学]