Title: Measurement of Interfacial Configurations on Bubbly Flow in 180.DEG.-Bent Tube Using Image-Processing Method.
Abstract: This paper presents an experimental study of the air-water bubby two-phase flow in a U-tube (bent at 180 degrees) . The bubble interfacial configurations were measured using the image-processing method. The diameter and the position of the bubbles in the tube cross section were at right angles to each other. The measurements revealed that the bubbly flow travelled near the inside wall of the bent tube due to centrifugal force. The relative high secondary flow from towards the outside wall of the bent tube separated the bubbles from the inside wall of the tube at the top the bend, i. e., at the 90-degree point. Bubble elongation in the tube diametric direction was shown at bends of 90-180 degrees.