Turbulence and entrainment in an atmospheric pressure dielectric barrier plasma jet

Particle image velocimetry, laser-induced fluorescence, and computational modeling are used to quantify the impact of plasma generation on air entrainment into a helium plasma jet. It is demonstrated that discharge generation yields a minor increase in the exit velocity of the gas. In contrast, the laminar to turbulent transition point is strongly affected, attributed to an increase in plasma-induced perturbations within the jet shear layer. The temporal decay of laser-induced fluorescence from OH is used as an indicator of humid air within the plasma. The results show that plasma-induced perturbations increase the quenching rate of the OH-fluorescent state; indicating that shear-layer instabilities play a major role in determining the physicochemical characteristics of the plasma.