An Experimental Investigation of the Liquid Flow Induced by a Pulsed Electrical Discharge Plasma

Plasma-liquid interfacial layer detected by in situ Raman light sheet microspectroscopy

“…For a second-order reactiondiffusion problem (which would apply to reaction R4), 1 To explore this possibility, consider the Péclet number for mass transfer: Pe = uLOH/D. The surface flow velocity may be estimated to be u  10 cm/s based on modeling and experimental results (Shimizu et al 2011, Lindsay et al 2015, Thagard et al 2018, Semenov et al 2019, yielding Pe  1200. Thus, convective mass transport should bear some importance, making the first Damkohler number Da = kcOH relevant to the analysis.…”

Instant switching control between two types of plasma-driven liquid flows

“…[9][10][11][12] Therefore, elucidating the mechanism of plasma-driven liquid flows is crucial to explain their interactions. Various possible driving forces, such as shearing forces due to gas flow, 13,14) electrohydrodynamic flows, [10][11][12]15) electrical field/momentum transfer due to charged particles, 16,17) pressure waves, 18) thermal convection, 9) and the Marangoni flow, [19][20][21][22] have been proposed; however, the mechanisms remain unclear. Two types of plasma-driven liquid flows with different directions in bulk liquid have already been reported and comprehensively investigated.…”

“…Two types of plasma-driven liquid flows with different directions in bulk liquid have already been reported and comprehensively investigated. 20,[22][23][24][25] However, the relationship between the properties of the plasma jet and the two types of liquid flows still need to be determined. Under such circumstances, this study succeeded in instant switching control between the two types of plasma-driven liquid flows by changing the frequency of the power supply for argon (Ar) plasma jet generation.…”

“…The conditions on the liquid side were fixed herein but are also known to affect the plasma-driven liquid flows. 20,22) Therefore, performing this study under various liquid conditions is necessary. Although it should be noted that the liquid contains the nylon particles for the PIV measurement, we consider that the effects of electrical interaction between the plasma and the nylon particles on the liquid flows are not major.…”

“…Clarifying the details of how these spectral differences affect the chemical and physical actions on the liquid surface and examining the relationship with the liquid flows are crucial in future studies. The conditions on the liquid side were fixed herein but are also known to affect the plasma-driven liquid flows 20,22). Therefore, performing this study under various liquid conditions is necessary.…”