A simplified CFD model for air-lift artificial upwelling

Air-lift artificial upwelling was simulated through a simplified computational fluid dynamics (CFD) model of two-phase flow in an upward pipe. This model is based on the momentum transfer between the two phases. An algebraic turbulence model was employed to enclose the equations. The volumetric flow rates of the liquid and the gas phases, the void fraction distribution, and the pressure and velocity profiles along the axial coordinate were calculated in the stationary state. Numerical tests were conducted to verify the model. The good agreement obtained between the computational results and the field test measurements with cross-shaped air injectors demonstrates the capability of this model for dispersed bubbly flow conditions. Comparisons with the analytical theory were also made. The results indicated that the proposed engineering-oriented model is efficient for the optimization of the system.