EFFECT OF BUOYANCY ON EHD-ENHANCED FORCED CONVECTION IN A VERTICAL CHANNEL WITH NON-SYMMETRIC ELECTRIC FIELD
The present study investigates the effect of thermal buoyancy on heat transfer enhancement in a vertical channel under the influence of non-symmetric electric field. The electrical field is generated by a wire electrode charged at a high voltage of direct current with positive polarity. Numerical calculations have covered a wide range of parameters (i.e., V0 = 12, 15 and 18 kV, Re = 500, 1000, and 2000 and Gr = 5000). Similar to the previous study with symmetrical electric field, the resulting flow and temperature fields can be either steady or oscillatory. All opposing flows are found to be steady disregard of the electric field condition (symmetric or non-symmetric) while aiding flows under non-symmetric electric field turn out to be oscillatory. Also found is that heat transfer enhancement by opposing flows is more effective than aiding flows. Most importantly, the present study has shown that the presence of thermal buoyancy can greatly offset the benefit of using non-symmetric electric field in the enhancement of heat transfer as reported in the previous study.