Numerical results are presented for the effects of electric field on natural convection in an enclosure filled with air and heated from below. The geometry considered is a two-dimensional rectangular cavity with an aspect ratio of one fifth. The electric field is generated by positive corona discharge from a wire electrode placed at the center of the enclosure. Numerical calculations have covered a wide range of parameters (i.e., 10{sup}3 ≤ Ra ≤ 10{sup}6 and V{sub}0 = 12, 15 and 18 kV). Due to the impingement of corona wind on the heat transfer surfaces, the flow and temperature fields may become steady, periodic, or non-periodic depending on the applied voltage and Rayleigh number. Because of the EHD-induced oscillatory flows, heat transfer is enhanced and is most significant at small Rayleigh numbers. It is found that heat transfer enhancement increases with the applied voltage but decreases with the Rayleigh number.
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