INVESTIGATION OF BUBBLE MOVEMENT THROUGH SUDDEN CONTRACTION IN CHANNEL: A LATTICE BASED APPROACH
Numerical study has been carried out, to study the effect of sudden contraction on low density liquid bubble flowing in high density liquid along a channel, using Lattice Boltzmann method. Diffused interface concept has been used for the capture of complex interface structure. A kerosene bubble is kept in a water medium which allows the bubble to rise up in a rectangular channel with the contraction ratio (Wa/Wb) of 0.5. The hydrodynamics of rising low density liquid bubble inside a conduit at sudden contraction has been studied thoroughly. Shape reorientation of the liquid bubble for smooth advancing has been captured by studying the phase contours in lattices. As the bubble passes through the smaller cross-sectional area it tries to elongate and tend to form a Taylor bubble shape. Formation of circulations below the contraction has been clearly shown with the help of streamlines and velocity vectors. Effect of sudden contraction on the vorticity magnitude has been studied and an account of increase of vorticity is demonstrated.