基于视频处理的分层流持液率测量

截面持液率是气液两相流的基本参数之一。在气液两相实验系统上进行实验，采用高速摄像机系统获取了水平管气液两相流流型视频，提出了一种针对两相流动视频实现持液率检测的新方法。该方法针对自然光下拍摄的气液两相分层流图像气液区域与气液界面模糊、边缘难以直接提取的难点，采用新的递变规律加强图像的灰度使画面效果清晰化，通过中间线计算法提取气液边界线，进而通过提取的气液界面距离管底高度数据，计算管路持液率，其中包括同一帧图像不同截面的持液率以及同一截面持液率随时间的变化情况。实践证明：在自然光干扰较大的拍摄条件下，该方法能够获得连续、清晰的气液相边界，可推广应用于其他流型图像的分析和检测。（图9，参8）。

Measurement of liquid holdup of stratified flow based on video processing

Liquid holdup is one of the basic parameters of gas-liquid two-phase flow. A method to detect the liquid holdup based on the gas-liquid two-phase flow video, which is captured using high-speed camera system in the horizontal tube, is proposed. Because the two-phase stratified flow image taken under natural light appeared dim between the gas-liquid region and interface of gas-liquid and difficult to directly extract their margin, this new method adopts new periodic changing rule to enhance the grayscale of the images to make them more clear, uses medium line calculation method to extract the gas- liquid interface line and then calculates the liquid holdup using the extracted dada of distance between gas-liquid interface and the bottom of the pipe. The calculated liquid holdup includes the liquid holdup of different sections in the same image frame and the ones in the same section but at different time. Practical application shows that under the condition of severe natural light interference, the proposed method is able to obtain continuous, clear gas-liquid interface, and therefore can be applied in the analysis and detection of other flow pattern images. （9 Figures, 8 References）