Numerical Simulation of the Behavior of Taylor Bubbles in Non-Newtonian Fluids Using OpenFOAM

Taylor bubbles are commonly utilized in a wide range of industrial applications involving non-Newtonian fluids, and a thorough understanding of the relevant knowledge is helpful to the design optimization of related industrial processes. This study investigated the behavior of Taylor bubbles in shear-thinning fluid using OpenFOAM. The numerical method is verified by comparing the results with experimental data, additionally, the effects of flow index n, surface tension σ, and zero shear rate viscosity μ0 on the motion behavior of Taylor bubbles were investigated. The results show that as the flow index n and zero shear viscosity μ0 increase, the terminal velocity of the Taylor bubbles decreases. The impact of various operating parameters on the bubble nose's form is insignificant. Regarding the liquid film surrounding the bubble, when n is small, the bubble rear is broken seriously, resulting in a shorter bubble and thinner liquid film. As the flow index n increases, the bubble elongates, and the liquid film becomes thicker, the length of the wake behind the Taylor bubble decreases. The surface tension mainly affects the bubble rear but has little impact on the bubble nose and rising velocity. For high μ0, the bubble rear does not break, and the shear thinning area is small.