Interface tracking simulations of bubbly flows in PWR relevant geometries

Studies of Bubbly Channel Flows by Direct Numerical Simulations

Recent DNS studies of buoyant bubbly flows in vertical channels are discussed. Simulations of nearly spherical bubbly flows in vertical channels show that the bubbles move towards the wall for upflow and away from the wall for downflow in such a way that the core is in hydrostatic equilibrium. For downflow the wall layer is free of bubbles but for upflow there is an excess of bubbles in the wal...

Evolving Solitons in Bubbly Flows

At the end of the sixties, it was shown that pressure waves in a bubbly liquid obey the KdV equation, the nonlinear term coming from convective acceleration and the dispersive term from volume oscillations of the bubbles. For a variable u, proportional to -p , where p denotes pressure, the appropriate KdV equation can be casted in the form ut 6uu~ + u ~ = 0. The theory of this equation predicts...

Interface Tracking for Axisymmetric Flows

A front tracking method for inviscid gas dynamics is presented. The key constructions and algorithms used in the code are described and the interrelations between shock capturing, interface dynamics, computational geometry, grid construction, and parallelism are discussed for the code as a whole. Validation is carried out by comparing the single mode bubble velocity for Rayleigh–Taylor instabil...

Numerical Simulation of Turbulent Bubbly Flows

A mathematical model for turbulent gas-liquid flows with mass transfer and chemical reactions is presented and a robust solution strategy based on nested iterations is proposed for the numerical treatment of the intricately coupled PDEs. In particular, the incompressible Navier-Stokes equations are solved by a discrete projection scheme from the family of Pressure Schur Complement methods. Nove...

Mathematical Modeling of Bubbly Flows 1