Taylor-Couette流场特性的PIV测量及数值模拟

采用粒子成像速度场仪(PIV)和数值模拟(CFD)对Taylor-Couette 流场进行测量,获得各转速下涡流场信息。将同等条件下PIV测量结果与数值模拟结果相联系,对比分析不同旋转雷诺数范围内涡流场中不同径线和中轴线上各向速度的变化特征。结果表明,各种特征存在一定的转速分段范围:在2~7r/min(Re为100~350)时,各向速度特征为层流涡特性,在7~40r/min(Re为350~2000)时,各向速度特征为波状涡特性,在40~60r/min (Re为2000~3000)时,各向速度特征为调制波状涡特性,当转速大于60r/min(Re大于3000)时,各向速度特征为湍流涡特性。根据不同角度获得的各向速度特征对应的内筒转速、旋转雷诺数与流场涡形态的关系,明确分析出特定几何条件下,泰勒涡发生形态转变的旋转雷诺数,以便于深入探究泰勒涡流场的特性,定量分析涡运动形态特征。

PIV measurement and numerical simulation of Taylor-Couette flow

Particle image velocimetry (PIV)and numerical simulation (CFD)were applied to measure the Taylor-Couette flow and the information of the vortex flow at different rotation speeds was obtained.The measurement results by PIV were compared carefully with numerical results by CFD under the same condition,and the variation characteristics of all phase velocities along the central axis and different radial lines of the vortex flow with different Reynolds num-bers were contrastively analyzed.The results indicate that there existed several speed ranges with various characteristics:when the rotation speed was within 2~7r/min(Re= 100~350)laminar vortex flow was found according to the characteristics of phase velocity vectors;when the rota-tion speed was within 7~40r/min(Re= 350~2000)wavy vortex flow was found;it was modula-ted wavy vortex flow when the rotation speed was within 40~60r/min(Re= 2000~3000);and it was turbulent vortex flow when the rotation speed was higher than 60r/min(Re≥3000).Then,in order to deeply explore the characteristics of Taylor vortex flow and the features of the vortex motion by quantitative analysis,this research explicitly analyzed the Reynolds number ranges where the form of the vortices was found to change under a certain geometric condition according to the relationship among the characteristics of the form of vortices,their corresponding rotation speeds,and the Reynolds number.