Numerical Investigation of Electrohydrodynamic Forced Convection Heat Transfer from a Circular Cylinder

Abstract

In this study, the heat transfer by forced convection over a circular cylinder was studied numerically in the presence of an electric field and the effects of the installation angle of discharge electrode, wire–cylinder spacing and electrohydrodynamic (EHD) number were also investigated. The results showed that the location of discharge electrodes has a considerable effect on changing the flow pattern, velocity profile, and scheme of thermal boundary layer. It was found that the corona wind can increase the local and average Nusselt numbers. However, in some cases, the EHD actuator had a negative effect on the convective heat transfer rate due to the interaction between the corona wind and the main flow. In addition, EHD enhancement is more effective at high EHD numbers and low wire–cylinder spacing values. Based on the results, a maximum enhancement of 42.1% was observed in the average Nusselt number using the EHD technique. Finally, the EHD efficiency was calculated as an outstanding result to assess the performance of the EHD actuator. The results revealed that although the EHD is more effective at higher electric field strengths in terms of thermal enhancement, it is not cost-effective because of the high power consumption.