Gas bubble velocity measurements using high-speed images of gas-liquid flows

A technique to measure gas bubble velocities using digital image analysis of high-speed images of gas-liquid flows has been developed. The gas slug and bubble velocities are estimated using two separate image processing algorithms: a supervised motion tracking algorithm and an edge detection cross-correlation algorithm. The supervised motion tracking algorithm allows the user to identify and track the movement of distinguishable gas bubbles and slugs. The edge detection cross-correlation algorithm uses standard edge detection routines to identify the boundaries of the slugs and bubbles. The displacement of the bubbles between two frames is obtained through a cross-correlation analysis between the frames. Results obtained from the quantitative noninvasive flow visualization and image analysis techniques compare favorably with results from hot film anemometry measurements.