3-D EHD enhanced natural convection over a horizontal plate flow with optimal design of a needle electrode system

The present study is intended to investigate the effect of electrohydrodynamic (EHD) enhanced heat transfer on natural convection flow. The flow is assumed to be three-dimensional, turbulent and steady. An experiment was carried out to verify the accuracy of the numerical results and to provide electric properties such as induced current and power consumption to be used as the criteria for the numerical solution procedures. An optimal analysis was carried out along with the simplified conjugate-gradient method, where the objective function was defined as the heat transfer enhancement per input power, which is maximized by searching for the optimum electrode pitch ( SL ) and height ( H ) combination. A search for the optimum electrode pitch ( SL ) and electrode height ( H ), ranging from 50 mm < SL < 200 mm and 15 mm < H < 55 mm, respectively, with V 0 (12, 14, 16, 18 and 20 kV) and Δ T (33, 53 and 73 K), was performed, respectively. The results showed that the maximum heat transfer enhancement per power consumption reached 4.42–9.72.