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. Plasma induced instabilities grow in the jet shear layer, increasing air entertainment at all spatial positions