DIRECT NUMERICAL SIMULATIONS OF TWO-PHASE FLUIDS INTERFACE IN 2D ROTATING DRUMS USING A COUPLED VOF–IBM NUMERICAL APPROACH

Abstract

Rotating drums play important roles in numerous industrial applications, such as mineral processing. This work is focused on the numerical study of the interface evolution in liquid-liquid and liquid-gas phase rotating drums. A new coupling strategy between volume of fluid (VOF) and immersed boundary method (IBM) approaches is developed. Relevant dimensionless numbers, including Reynolds, Froude, and Bond numbers, alongside viscosity and density ratios, are considered for the flow pattern characterization. Direct numerical simulations are performed in order to explore flow regimes within the rotating drum, addressing a gap in the literature concerning less-explored flow patterns, particularly in the rotating drum containing liquid-liquid phases. The flow pattern families characterizing rotating drums carrying liquid-liquid phases found in this study are (i) gravity stratified, (ii) mixing, (iii) annular, and (iv) rotation stratified flows. Additionally, the characteristic flow pattern families, (i) gravity stratified, (ii) pool, (iii) annular with pool, and (iv) annular flows, are identified in rotating drums carrying liquid-gas phases. The difference in the transitory responses between the rotating drum featuring liquid-liquid and liquid-gas phases is also shown and discussed. The main results highlight significant contributions for understanding the dynamics of rotating drums, particularly concerning the transitional interface development. By identifying new flow patterns and exploring transitional phenomena, this study enriches the understanding of complex fluid behavior within rotating drum configurations.