Author(s): Dasun Lahiru Muthumala Jayasooriya; Maggie Bingo; Eoghan Clifford; Stefan Felder; Matthias Kramer; Sean Mulligan
Linked Author(s): Matthias Kramer, Maggie Ntombifuthi Bingo, Stefan Felder, Eoghan Clifford, Sean Mulligan
Keywords: Ir entrainment oxygen transfer fluid viscosity plunging jet Computational Fluid Dynamics
Abstract: Air entrainment is an area with a growing emphasis in various engineering and industrial fields, such as wastewater treatment and chemical mixing processes. The entrainment of a gas such as oxygen is crucial in many processes in these fields. Several methods of air entrainment are used in engineering applications, such as surface aerators, fine bubble diffusers, plunging jets, etc. The plunging jet system is a classical method of air entrainment which uses a high-speed jet of water impinging on a liquid water tank underneath it. The bubble generation and air entrainment process in a plunging jet is dependent on various factors such as jet impact velocity, jet nozzle characteristics, jet angle, etc. and fluid parameters such as viscosity and surface tension. Typically, the impact of fluid parameters is accounted for, when modelling aeration processes using what is known as the “alpha” factor. However, the underlying mechanisms which influence the alpha factors are not yet sufficiently understood and thus not adequately accounted for in models. Therefore, this research, using Ansys FLUENT, presents insights into modelling bubble behavior and air entrainment under different viscosity levels. The models are validated using data from an in-house plunging jet experimental system. Improved modelling capability in this area can lead to improved engineering design and innovation as well as better capacity to optimize technology to reduce resource consumption.
Year: 2025