Fluid flow and heat transfer characteristics of corona wind in cross-cut finned channel

An efficient heat exchanger should exhibit superior heat transfer performance with low pressure drop. However, in the case of forced convection such as fan cooling, the heat transfer performance is proportional to the area of the extended surface and the airflow rate, which accompanies a pressure drop and imposes a limit on performance improvement. Herein, flow acceleration using corona wind is proposed as a method to simultaneously solve the problem of pressure drop in heat exchangers and improve heat transfer performance. Further, the concept of accelerating the flow of local regions around the surface by installing a wire electrode on the fins of a heat exchanger for corona wind generation is implemented. In addition, an original form of heat exchange fins that combine wire electrodes and cross-cut fins is presented. By controlling the flow velocity direction of the corona wind in the downstream direction of the mean stream, the pressure drop is suppressed and maximize the heat-transfer performance. Detailed experimental data on the velocity and temperature of the corona wind from the wire to the cross-cut fins with various wire materials, positions, and dimensionless design parameters in the channel are presented. In addition, the flow patterns of the accelerated corona wind are analyzed using particle image velocimetry on the cross-cut fins. The results confirm that the corona wind can be applied to a cross-cut fin array and can significantly enhance the heat-transfer performance of the fins. •The new type of cross-cut fin corona wind heat exchanger was presented.•2 m/s of local velocity was obtained near the wall with 12 kV of applied voltage.•Parametric study was performed for the appropriate geometric dimensions for the cross-cut fins.•Optimum ratio of cross-cut fin per fin gap (Lf/LC) was derived by sixteen.•A maximum enhanced heat transfer coefficient of 36% was observed at the cross-cut fins when corona wind was applied.