  In this paper, we present the algorithm for the simulation of a single bubble
rising in a stagnant liquid using Euler-Lagrangian (EL) approach. The
continuous liquid phase is modeled using BGK approximation of lattice Boltzmann
method (LBM), and a Lagrangian particle tracking (LPT) approach has been used
to model the dispersed gas (bubble) phase. A two-way coupling scheme is
implemented for the interface interaction between two phases. The simulation
results are compared with the theoretical and experimental data reported in the
literature and it was found that the presented modeling technique is in good
agreement with the theoretical and experimental data for the relative and
terminal velocity of a bubble. We also performed the grid independence test for
the current model and the results show that the grid size does not affect the
rationality of the results. The stability test has been done by finding the
relative velocity of a bubble as a function of time for the different value of
dimensionless relaxation frequency. The present study is relevant for
understanding the bubble-fluid interaction module and helps to develop the
accurate numerical model for bioreactor simulation.
