Gas-plasma jet interaction with liquids: modelling and experiments

Presented by: Juliet Ojiako (Loughborough)

Abstract

Gas-plasma interactions with liquids find applications in industries and medicine. We aim to model the interaction of an air-plasma jet with a liquid accounting for hydrodynamics, electro-hydrodynamics and chemical kinetics. This involves the calculation of the deformation of the surface of the liquid and flows generated in the gas and in the liquid [1], the rate at which the generated long-lived plasma species are transferred to the liquid as well as the associated chemical reactions. When a plasma strikes a liquid, there is also an associated electric field and the plasma itself can also be quite hot. These two effects are decoupled and analysed separately. 

We start by using the generated long lived plasma species [2,3] determined from experiment as the initial conditions for the plasma jet striking a liquid surface and quantify the plasma species that are transported into the liquid and the rates of chemical reactions, taking into account the motion of the fluid. 

The problem is solved using the Computational Fluid Dynamics package in COMSOL and the numerical results are compared with experiments. 

[1] C.J.Ojaiko et al, Deformation of Liquid Film by an impinging Gas Jet: Modelling and Experiments, Proceedings of the 6^thInternational Conference on Fluid Flow, Heat and Mass Transfer (FFHMT’19). Avestia Publishing FFHMT 171.

[2] Z. C. Lui et al, Physicochemical processes in the indirect interaction between surface air plasma and deionized water, J. Phys. D: Appl. 48, 495201

[3] A. Wright et al, Microbubble-enhanced DBD plasma reactor: Design, characterisation and modelling, Chem. Eng. Research & Design, 144, 159-173