Development of algorithm to model dispersed gas-liquid flow using lattice Boltzmann method

TL;DR

This paper introduces a lattice Boltzmann-based algorithm for simulating a single bubble rising in stagnant liquid, validated against theoretical and experimental data, aiding bioreactor modeling.

Contribution

The paper develops a coupled Euler-Lagrangian lattice Boltzmann algorithm for bubble-liquid interaction, validated with grid independence and stability tests.

Findings

Model accurately predicts bubble velocity compared to theory and experiments.

Grid size does not significantly affect simulation results.

Model demonstrates stability across different relaxation frequencies.

Abstract

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.