2D and 3D Analysis of bubble velocities, trajectories and travelled distances rising in a periodic channel using a highly efficient identification algorithm
Please login to view abstract download link
We present simulation results and analysis of multiphase flow with a level of gravity in a periodic channel. The simulations were performed with CaNS- Fizzy [1], a DNS multiphase CFD solver. A highly efficient identification algorithm identifies all connected components (bubbles) at each timestep and through time along the running of the CFD solver. The coupling of this identification algorithm with the CFD solver allows for high level of analysis for individual bubbles and the whole bubble population. For two different fluids the velocities and trajectories of the bubbles of the lighter phase were analysed amongst other things. The volume fraction, Φ, of the lighter phase was 10% and the qualities of the phases correspond to geothermal applications with water and gas. The results consist of grid sensitivity analysis, 2D and 3D cases and analysis of turbulent kinetic energy and volume, velocity, expected trajectory and travelled trajectory of bubbles. The grid sensitivity analysis includes reaching conformity with the results of the identification algorithm. The differences between 2D and 3D data are discussed. Figure 1 shows trajectories and volume equivalent circles of each bubble in a walled periodic 2D channel with gravity acting in the x-direction, [-9.8,0] m/s2.
