This study investigates the potential of airflow shielding by utilizing the induced flow from a dielectric barrier discharge plasma actuator (DBD-PA). The interaction between a horizontal axisymmetric jet and a vertically oriented induced flow was examined experimentally. Particle image velocimetry (PIV) measurements were performed to evaluate the velocity fields of laminar and turbulent jets, which interacted with the induced flow under varying applied voltages, flow rates, and actuator installation positions. The experimental results reveal two fundamentally different shielding mechanisms. For the laminar jet with a uniform velocity profile, the induced flow caused a significant upward deflection of the entire jet, and the magnitude of this deflection increased with higher peak-to-peak voltage. Furthermore, the interaction generated new velocity fluctuations, concentrating disturbance energy in the shear layer. In contrast, for the fully developed turbulent jet, the induced flow interacted with the expanded lower boundary, causing localized flow deceleration and leading to a bifurcation in which part of the jet was forced downward. In this case, turbulent kinetic energy was concentrated within the deceleration region. These findings demonstrate that the induced flow generated by a DBD plasma actuator effectively modifies both mean velocity and turbulence characteristics of jets. To evaluate shielding performance, two types of flow-rate deficit ratios were estimated from the velocity distribution. Both increased with higher applied voltage as well as with the ratio of jet width to the vertical distance of the DBD-PA, indicating that the flow-rate deficit ratios can serve as useful indices for assessing interaction effects.
KOBAYASHI et al. (Thu,) studied this question.