Experimental validation of 3-D Lagrangian VOF model: Bubble shape and rise velocity

A novel 3-D computational fluid dynamics model using an advanced Lagrangian interface tracking scheme was studied to find the time-dependent behavior of gas bubbles rising in an initially quiescent liquid. A novel least-square approach is used to determine the normal behavior at the interface for an accurate reconstruction and advection of the interface based on mollification of the color function by convolution. The incompressible Navier-Stokes equations are solved using an accurate discretization scheme to obtain the flow field of the gas and liquid phase. Detailed experiments Of single rising bubbles of different sizes were performed to compare the shape, rise velocity and pressure signal of the bubble with the performed simulations. The developed Lagrangian volume-of-fluid model could accurately track the motion and shape of the gas-liquid interface embedded in a flow field with significant vorticity.