Effects of buoyancy on electrohydrodynamic-enhanced forced convection in a vertical channel

Heat transfer enhancement using the electrohydrodynamic technique is numerically examined for laminar mixed convection in vertical channels. The electrical field is generated by positive corona from a wire electrode charged with a DC voltage of 15 kV. The flow Reynolds numbers considered are 600, 1200, and 1800, with Grashof numbers varying from 10(4) to 10(6) for both aiding and opposing flows. In addition to heat transfer enhancement, attention is also focused on the effect of added thermal buoyancy on the flow stability when the temperature difference between the flowing gas and bounding walls cannot be neglected.