A Lattice Boltzmann Model for Simulating Realistic Large Viscosity/Density Ratio of Multi-Component Bubble Flow in Microchannel

Abstract

Microchannel bubble flow has been involved and applied in a variety of engineering fields, and the study of bubble flow behaviors in microchannel has great value of engineering applications. Because multiphase flow in microchannels is a very complex transport process and limited by the microchannel scale, there are still technical difficulties in the design and preparation of microscale experiment and measurement devices in order to obtain the details of multiphase microscopic flow processes under the actions of multiple influencing factors. Numerical simulation has gradually become a powerful tool for the study and characterization of microchannel fluid flow properties. The materials of the real microchannel gas-liquid system are characterized by multiphase, multicomponent, large viscosity ratio, and large density ratio, and its flow is characterized by the existences of real inlet, outlet and solid wall boundaries and local deformation of the wall boundaries. Through adjusting the boundary condition strategy and optimizing the multicomponent scheme of the pseudo-potential lattice Boltzmann multiphase model, a lattice Boltzmann computational model for simulating realistic large viscosity/density ratio of multi-component bubble flow in microchannel was established in the present paper. By theoretical and qualitatively experimental verifications, the accuracy of the established model was verified from different angles. Utilizing the model, the formation and development of bubbles under different conditions were simulated to investigate the influence of different factors on the evolution of bubbles. The simulation results further verify the applicability and accuracy of the model, and meanwhile, supplement and improve the existing theories relating to the microchannel bubble flow.

Keywords: Lattice Boltzmann method, Pseudo-potential model, Microchannel, Large viscosity/density ratio, Bubble flow