In plasma-liquid interactions, various phenomena such as strong evaporation, surface deformations, droplet ejection, and the formation of an electric double layer can occur. The interaction is influenced by the electric field at the interface, which modulates heat flux and ion bombardment, affecting evaporation, sputtering, and droplet ejection. The near-electrode model for solid surfaces may be inaccurate for liquid surfaces due to the presence of droplets, which alter the sheath chemistry. Accurate modeling of the plasma-liquid interface requires understanding species and charge exchange, often necessitating a fast transient model to account for the dynamic nature of the interaction.
The multi-fluid model considers plasma as separate fluids, assuming local thermodynamic equilibrium (LTE) for each species without requiring the same equilibrium temperatures. This model includes mass, momentum, and energy conservation for each plasma species while tackling the electromagnetic field with Maxwell’s equations. Different levels of simplification can be applied, from multi-fluid models to single-fluid LTE models, each addressing various aspects of plasma behavior and interactions.
The project also involves multi-phase, turbulence, and radiation modeling. Interface tracking techniques are used for plasma-liquid interactions, with the Navier-Stokes equation applied on the liquid side. Micro-droplet formation, detachment, and evaporation are simulated, considering the effects of turbulence and using methods like Large Eddy Simulation (LES) and SST k-omega models. Radiation modeling employs the P1-approximation for spectral averaging due to complex frequency-dependent absorption coefficients
Overall, the project aims to simulate the detailed physics of the plasma-liquid interface, exploring the effects of magnetohydrodynamics (MHD) and plasma bombardment on liquid interface morphology. The multi-fluid modeling approach provides a comprehensive framework for understanding the complex interactions at the plasma-liquid boundary.