基于DPIV的微气泡瞬态数密度与粒径谱测量研究

基于数字粒子图像技术及CCD成像的景深原理,提出了测算微气泡数密度和粒径谱的方法。推导出了测算数密度和粒径谱的公式,建立了算法流程。最后设计了实验系统,用该算法测量了由陶瓷管微气泡发生器产生的气泡数密度和粒径谱。研究发现,应用景深原理测量的气泡数密度规律与实际数据相符,水槽中气泡的数密度与调频器的频率正相关。基于内接圆标记的气泡粒径测算结果的变化规律与已有实验数据的规律一致,较之直接提取气泡图像像素计算半径更加准确。

The Study of Measuring Transient Number Density and Radiuses Distribution of Microbubbles Based on DPIV

A method of measuring number density and radiuses distribution is presented based on the digital particles image processing technology and the principle of image field.The functions as well as the algorithm flow are deduced used to calculate the number density and radiuses distribution.At last,a system is designed including high resolution camera and microbubble generator.It is found that the bubbles density variation matches well to the practical data,and that the density is positive correlation with the frequency variator.The results of bubble radiuses based on the demarcating inscribe circle match well with the subsistent data,showing an accurate effect.