Rising of air bubble in water-sugar solution (Bhaga and Weber, 1981)
This movie shows the numerical solution of an initially spherical air bubble in a quiescent water-sugar solution using a moving frame view point where the bubble’s centroid remains fixed in space while fluid flows downward. In this approach, the interface mesh is built as a set of interconnected nodes and finite triang le elements. The red and blue colours of the background tetrahedral mesh represent the horizontal velocity component. Red color is positive velocity and blue color is negative velocity. As can be seen, in the current approach, very low adaptive remeshing is required since bubble is fixed in space. Additionally, only the normal component of the velocity is used to move nodes lying at the the interface, thus avoiding extensive remeshing at the surface. This approach leeds to very accurate results when simulating two-phase flow systems with high interface deformation.