Heat transfer enhancement by an electrohydrodynamic plume induced by ion injection from a hyperbolic blade

Abstract

The electrohydroyanmic (EHD) plume induced by charge injection from a hyperbolic blade into a dielectric liquid was considered to actively enhance heat transfer. We numerically studied an upward-facing hot plate with constant temperature cooled by an impinging ionic jet that results from a strong and autonomous injection. It is shown that the heat transfer rate expressed with the local and averaged Nusselt numbers are dramatically increased. In addition, we observe that the Nusselt number is independent of the Rayleigh number Ra (2.5×10³ ≤ Ra ≤ 1.0×10⁴) for all electric Rayleigh numbers T considered (5.0×10² ≤ T ≤ 2.0×10⁴ ), which reflects the fully dominant role of the electric force.