How Multi-Phase Electro-Hydrodynamics Drives Plasma-Induced Liquid Flows

Plasma-induced liquid flow (PILF) is a fundamental part of plasma-liquid interactions we know next to nothing about, but is vital to the transport of plasma-produced species through a liquid. One PILF mechanism is electro-hydrodynamic forces that occurs in the gas, liquid and interfacial phases in different ways. We will discuss the theory behind electro-hydrodynamics during PILF, and show experimentally for the first time which phase dominates PILF during the interaction of a plasma jet and de-mineralised water. Our results show gas phase electro-hydrodynamics dominating flows in floating liquids, whereas interfacial phase electro-hydrodynamics (otherwise known as Maxwell stress) dominates in grounded liquids.