GAS BUBBLE SIZE AND VELOCITY MEASUREMENTS USING HIGH-SPEED IMAGES OF GAS-LIQUID FLOWS

A quantitative flow visualization system has been developed to measure gas bubble size and velocities of gas-liquid flows. The images are acquired using a high-speed digital imaging system. An image processing algorithm based on standard edge-detection routines and morphological operations are used to demarcate the boundaries of the gas bubbles and obtain the bubble size distribution. The displacement of the bubbles between two consecutive frames is obtained through a cross-correlation analysis between the frames. Results obtained from the flow visualization and image analysis techniques are in good agreement with simultaneous measurements using hot-film anemometry.