Hydraulics of Air-Water Flow in a Pressurized Pipeline Model Using Image Processing

Document Type : Research Article

Authors

Associate Professor, Department of Civil Engineering, Isfahan University of Technology

Abstract

The study of two-phase fluid flow is of great importance in tunnels and pressurized pipelines, due to
the disturbances caused by pressure fluctuation, bubble bursting, energy release and erosion. The gas
releases from the water as the pressure reduces, and, hence, trapped in water pipelines. This effect has
been observed and found to be detrimental.
The image processing technique is applied for estimating different parameters such as; void fraction
and length, period and celerity of unstable two-phase slug flow, using Photoshop and Matlab software,
based on experimental model. Necessary images were collected using two digital cameras. It is shown
that, the image processing technique can be used as a good tool for determination of two-phase flow
characteristics. Results show that the slug flow characteristics including length, frequency and celerity
have significant effects on void fraction. By increasing the air/water discharge ratio the void fraction
increases and by in creasing the slug frequency the void fraction decreases.