Effect of Obstacle-Size on the Flow Structure of Two-Phase Flow Through Enlarging Channel

Abstract

A numerical investigation is made to study the effect of obstacle on the flow structure of air-water two-phase flow through a rectangular enlarging channel. The cross-section of the obstacle is considered as circular in shape. Effect of the diameter of the obstacle on the flow structure, pressure fluctuation and pressure distribution is made. Finite volume method (FVM) with mixture model and Eulerian model have been adopted for the present numerical simulation. Simulation results are obtained for both steady and unsteady cases. Due to change in both magnitude and direction of local velocities of fluid as the mixture approaches the obstacle, there is a marked difference in phase distribution around the obstacle. As the size of the obstacle increases, this becomes more remarkable. It can also be noticed that vortices before and after the obstacle becomes stronger with increase in size of the obstacle. The pressure difference is also monitored. It is found that as the obstacle size increases, the pressure drop increases and pressure distribution changes drastically.