Numerical Modeling of Air Entrainment Using a Three-Phase Mixture Approach

Abstract Air-water flows are ubiquitous in nature and engineering applications. In high-velocity air-water flows, the strong agitation of the free surface leads to the incorporation of pockets of air into the water flow in a process known as air entrainment. Experimental techniques encounter inherent limitations due to scale effects, as well as challenges arising from the inability or high degree of inaccuracy of traditional measuring devices in highly aerated flows. Numerical methods are also limited, either due to the significant computational costs associated with scale-resolving techniques or the elevated sensitivity to calibration parameters in time-averaged techniques. In this seminar, a novel theoretical/numerical model for the simulation of self-aerated flows for Reynolds-Averaged Navier-Stokes (RANS) simulations will be presented. The new methodology introduces an air entrainment mechanism that does not depend on traditional air entrainment functions and does not require calibration. A modification in the formulation of the Volume-of-Fluid method allows for capturing the increase in water depth due to the presence of bubbles. 

Bio Federico Zabaleta is a postdoctoral fellow at the Center for Turbulence Research at Stanford University, working with Professor Parviz Moin on predictive high-fidelity simulations of aircraft icing. He holds a BSc in Civil and Hydraulic Engineering from the University of La Plata, Argentina, and a MSc and PhD from the University of California, Davis. His doctoral research, under the supervision of Profession Fabian A. Bombardelli, was focused on the development of new numerical techniques for the simulation of air entrainment in free-surface flows.