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

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.