稀疏气泡流动的粒子跟踪测速技术研究

采用动态阈值技术实现了对气泡图像的正确分割，利用灰度加权方法提高了气泡颗粒的定位精度。根据稀疏气泡流动图像的特点，提出了一种新的基于相关的粒子跟踪测速算法（2-HPTV）。通过进行两时刻中围绕待研究气泡所取的两个小的诊断窗口的相关运算，成功实现了气泡颗粒的轨迹追踪。实验表明本文算法较传统的PIV技术在测速精度上有很大程度的提高，与4帧粒子跟踪测速算法相比，降低了对摄像机帧频的要求，具有较强的实用性。

Correlation based particle-tracking velocimetry for dilute bubbly flow

The images of bubbles in flow were segmented by means of dynamic threshold technology and gray weighted method was used to improve the precision of locating the central positions of bubbles. On this basis, a new correlation based 2-frame hybrid particle tracking velocimetry (2-HPTV) for measuring bubble velocity in dilute bubbly flow was developed. The path tracking of the bubble was realized by the correlation calculation of two small interrogation windows around the studied bubble at succession instants. The experiment result shows that the measurement precision of this method is higher than that of traditional PIV method and the image frames for video recording was reduced comparing with 4-frame particle tracking velocimetry.