Particle Image Velocimetry Measurements of the Mean Flow Characteristics in a Bubble Plume
Particle Image Velocimetry Measurements of the Mean Flow Characteristics in a Bubble Plume
复制标题
气泡羽流中平均流动特性的粒子图像测速测量
DOI：
--
复制
发表时间：
2007
期刊：
影响因子：
--
通讯作者：
S. Socolofsky
中科院分区：
文献类型：
--
作者：
Dong;Tirtharaj Bhaumik;C. Bergmann;S. Socolofsky
为了研究静止、非分层环境条件下无边界气泡羽流的流动特性，发展了一种利用粒子图像测速（PIV）和粒子跟踪测速（PTV）技术直接测量多相流速度场的方法。使用单个相机来获得包含气泡和流体示踪剂颗粒的图像。使用灰度阈值化，产生气泡的相分离图像，并且使用标准PTV方法从这些图像获得气泡速度。将常规PIV应用于混合流体图像，并使用速度阈值和矢量中值滤波器（根据PTV结果进行校准）去除气泡矢量。从分离的速度场出发，研究了气泡羽流的时均流动特性。高斯速度分布与夹带流体速度相匹配，而顶帽速度分布与气泡速度相匹配。同时给出了速度、羽流宽度、卷吸流量和速度的时均值。
A direct measurement method for the velocity field in multiphase flows using the particle image velocimetry (PIV) and particle tracking velocimetry (PTV) methods is developed to study the flow characteristics of an unbounded bubble plume in quiescent, unstratified ambient conditions. A single camera is used to obtain images containing both bubbles and fluid tracer particles. Using gray-scale thresholding, phase-separated images of the bubbles are produced, and bubble velocities are obtained from these images using the standard PTV method. Regular PIV is applied to the mixed fluid images, and bubble vectors are removed using a velocity threshold and vector median filter that is calibrated to the PTV result. From the separate velocity fields, the time-averaged flow characteristics of a bubble plume are studied. Gaussian velocity profiles match the entrained fluid velocity, and top-hat velocity profiles match the bubble velocity. Time-averaged values are also presented of velocity, plume width, entrained flu...