EXPERIMENTAL AND NUMERICAL STUDIES OF TWO PHASE FLOW REGIMES AROUND A CIRCULAR CYLINDERTHROUGH AN ENLARGING CHANNEL

Abstract

Experimental and numerical studiesare investigated to study the two-phase flow phenomena around a circular cylinder in a rectangular enlarging channel which has the dimensions (10 ´ 3 ´ 70 cm) enlarged from assembly circular tube of the two phases. Experiments are carried out inthe channel with air-water flow with different air and water flow rates. These experiments are aimed to visualize the two phase flow phenomena as well as to study the effect of pressure difference through the channel with the cylinder. All sets of the experimental data in this study are obtained by using a pressure transducer and visualized by a video camera for different water discharges (20, 25, 35 and 45 l/min) and different air discharges (10, 20, 30 and 40 l/min). Whilethe numerical simulation is conducted by using commercial Fluent CFD software to investigate the steady and unsteadyturbulent two dimensional flows for different air and water velocities with smooth enlargement. The results showed that the when air discharge increases, high turbulence is appear which generate more bubbles and waves