Euler-Euler Modeling of Hydrodynamics and Mass-Transfer in Bubbly Flows

CFD simulations of dispersed bubbly flow on the scale of technical equipment are feasible within the Eulerian two-fluid framework of interpenetrating continua. However, accurate numerical predictions rely on suitable closure models. To achieve predictive capability all details of the closure models have to be fixed in advance without reference to any measured data. Concerning the fluid dynamics of bubbly flows a baseline model has recently been proposed to this end and is shown to work for a range of different applications in a unified manner. This provides a reliable background which is well suited to add more complex physics. The content of the present contribution is such an extension to include also mass-transfer from / to the bubbles to the surrounding liquid. Shrinking / growth of the bubbles is taken into account within the inhomogeneous MUSIG model. A preliminary validation is provided using constant values for the mass transfer coefficient and the bubble size, but comparison is made with a set of experimental data providing axially resolved measurements. This contrasts previous works where comparison has been made only with integral data. A verification of the implementation is provided for the case with shrinking bubbles. The need for and requirements on suitable data for validation of a more refined model is emphasized.