LAUSR

Abstract This paper examines the surface cooling effect of a plasma actuator under wall confinement for surface cooling in small spaces inside electronic devices. Natural convection is suppressed in confined spaces with limited volume owing to a viscous drag that reduces the air flow. Plasma actuators can be applied in small spaces to induce air flow in the vicinity of the wall. We developed a plasma-actuator-cooling device in millimeter-order channels for cooling a surface in small confined areas. The dynamic temperature decrease on the stainless foil's surface was measured. The heat transfer coefficient showed different cooling effects for various channel heights. Channels with 2.5 mm of height demonstrated a high cooling effect comparable to the case without upper-surface confinement. Using particle image velocimetry, it was observed that the flow generated by the plasma actuator changes due to the presence of an upper-channel wall. It was also found that the suppression of the vortex generated downward of the electrode, owing to the existence of the upper wall, was the reason for high cooling performances in narrow channels of height 2.5 mm.