A Detached Direct Numerical Simulation of Two-Phase Turbulent Bubbly Channel Flow

Detached Direct Numerical Simulations (DDNS) of a two-phase turbulent bubbly channel flow at Reη = 180 (based on friction velocity and channel half-width) were performed using a stabilized finite element method (FEM), a level set algorithm to track the interface, and subgrid wall models. Fully developed turbulent single-phase DNS results obtained previously (Trofimova et al., 2009) with the same stabilized FEM code, were used as the initial flow field, and a level-set distance field was introduced to resolve and track the gas bubbles. Surface tension and gravity forces were used in the simulation to physically represent the behavior of a bubbly two-phase air/water flow. The DDNS results were averaged to obtain the mean liquid and gas velocity distributions, the local gas volume fractions, and the local turbulent kinetic energy and dissipation rate of the liquid phase. The liquid phase parameters were compared with the corresponding single-phase turbulent channel flow to appraise the bubbles’ influence on the liquid’s turbulence field and to quantify the importance of bubble-induced turbulence.