Flow pattern and power consumption of mixing highly viscous fluids under vertical acoustic vibration

This study analyzes the flow pattern and power consumption of mixing highly viscous fluids under vertical acoustic vibration, and investigates the effects of various process parameters on them. A numerical simulation of solid-liquid-gas multiphase flow has been created based on the Volume of Fluid (VOF) model and Discrete Phase Model (DPM), which has been verified through experimentation. When subjected to acoustic vibration, the fluids within the vessel and the wall interact dynamically, driven by a mixing force comprised of both pressure and viscous forces. Notably, the degree to which the fluids absorb mixing power is highly dependent on the mixing force itself, the vessel's velocity, as well as the phase difference between them. Throughout the mixing process, the amplitudes of the instantaneous mixing power and mixing force gradually diminish. Nevertheless, the effective mixing power indeed increases due to the phase effect. Increasing the frequency or amplitude of vibration can expedite the mixing process, leading to improved mixing uniformity and significantly enhancing the effective mixing power. However, the energy absorbed by the fluids is highly nonlinear with respect to the frequency or amplitude of vibration. Achieving higher mixing efficiency can be attained by selecting suitable vibration parameters without increasing power consumption. (c) 2023 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved.