Numerical Simulations of bubbly turbulent convection in cubical geometries

In this work we present numerical results of bubble dynamics in a turbulent Rayleigh–Bénard convection configuration, using our in-house code in a cubical geometry. The problem in hand is encountered in various natural phenomena as well as in industrial applications. A Eulerian–Lagrangian approach is developed for the mixture of liquid water and vapor bubbles. The liquid mean temperature is close to the saturation temperature and is governed by the quasi-incompressible Navier–Stokes equations that are solved using Direct Numerical Simulations (DNS) standards. The motion and growth/shrinkage of each individual vapor bubble is modeled and the effect of the bubbles on the fluid is accounted via momentum and energy exchanges between the two phases (two-way coupling).

At first, we describe the model used and its corresponding validation, involving isolated bubble dynamics and coupling between bubbly and bulk flows. In the second part, we consider the study of the flow topology, the bubble related statistics, the heat transfer (Nusselt number) and the turbulence statistics for different settings of the bubbly configurations.