Study on the characteristics of interfacial waves in annular flow by image analysis

Various scales of interfacial waves in length and amplitude are usually present at the gas-liquid interface. Complete knowledge of the interfacial waves is of great importance for the characterization of mass, momentum and energy exchange in annular flow. In this paper, an image analysis approach for interfacial wave recognition by detecting the spatiotemporal evolution of liquid film is introduced. Based on the image analysis, the identification and the characteristics of the interfacial waves are carefully investigated. The results indicate that the flow patterns identification and the pressure gradient are related to the characteristics and behaviors of interfacial waves. Remarkably, the analysis reveals that the orientation of interfacial waves is the significant criteria in flow patterns identification, and disturbance waves play the dominant role in pressure gradient. (C) 2019 Elsevier Ltd. All rights reserved.