Abstract Summary (Max 250 words)
Transport of soluble gases between bubbles and surrounding liquid is an important phenomenon in many industrial processes such as bio-reactor aeration, stripping, absorption, and electrolysis. An effective tool to understand such systems is numerical simulation of the relevant conservation equations coupled with a description of the mixture thermodynamics. We have developed a method for simulations where the soluble gas is approximated as ideal and the liquid is non-ideal (present as liquid and vapour). Since demonstrating the model’s equilibrium behaviour (Byrne and Shardt, Phys. Rev. E 111, 035306, 2025), we have extended the model to describe systems with convection. This model is implemented as a free energy lattice Boltzmann method (LBM), in which the transport equations are solved with LBM and the thermodynamics are incorporated through a free energy functional. This model employs a diffuse interface approach to describe interfaces between phases, which enables straightforward handling of merging and breaking interfaces. The model is stable up to high density ratios, O(1000), between the liquid and vapour phases. Mass transfer characteristics of dissolving soluble gas bubbles have been validated for both static and dynamic cases. Bubble shapes and rise velocities have also been validated up to Reynolds and Eotvos numbers of order one. The model has been used to simulate decomposition of a liquid to form gas bubbles (as during electrolysis of water), showcasing different bubble generation regimes.
