Validation of well-posed Euler-Euler models for gas-liquid flows in bubble columns

Bubble columns are widely used equipment in the chemical and biomanufacturing industries, ensuring the effectiveness of the property transfer by incorporating Computational Fluid Dynamics (CFD) simulations which allows a remarkable level of insight into the details of the flow. However, the accuracy of CFD models hinges on the selection of appropriate model closures, in addition to the adoption of an appropriate spatial discretization of the column geometry. In this work, we present a well-posed formulation of the Euler-Euler two-fluid model, which we use to perform a grid convergence study to provide criteria on the required spatial resolution to achieve a grid-converged numerical solution. We then leverage such a two-fluid model to simulate a pilot-scale bubble column, for which detailed experimental data are available in the literature, which are characterized by narrow bubble size distribution, to predict the bubble volume fraction and the probability distribution (PDF) of the gas velocity.