(438e) Numerical Investigation of Bubble Effects on Taylor-Couette Flow Patterns in the Weakly Turbulent Vortex Flow Regime
Bubbly gas-liquid Taylor-Couette vortex flow has been the subject of several recent investigations both because of interest in bubble-induced drag reduction and because such devices have potential applications to a variety of chemical and biochemical processing problems. The effect of bubbles on Taylor-Couette flow patterns and structures in weakly turbulent vortex flow regime is investigated by CFD simulation. The CFD model is based on an Eulerian-Eulerian two-fluid approach with constitutive closures for inter-phase forces and liquid turbulence and validated by comparing simulation predictions with previously published experimental data. The bubble spatial distribution patterns and mechanism by which the dispersed fluid reaches a non-uniform radial distribution is discussed, and the relative importance of various inter-phase forces is demonstrated. In addition, the axial expansion of Taylor vortices due to the presence of bubbles was reproduced by the simulations, and the influence of azimuthal Reynolds number and gas flow rate on vortex axial wavelength, liquid velocity and turbulence are discussed in detail.