Electrohydrodynamics Enhancement of Natural Convection Heat Transfer in Plate Surface

摘要

The experiment that electrohydrodynamics enhance natural convection heat transfer of R11 in plate surface was performed. The experiment involves natural convection from a horizontal plate immersed in R11 with a uniform electric field. Without electric field, the experimental data can be correlated by Nu = 0.0028(Gr Pr)~(0.5). When a electric field is exerted on the fluid of heat transfer, the Nusselt number enhancement is correlated in terms of a electrical Rayleigh number, Ra_(El), to account for the effect of an electric field on natural convection. The correlation, ΔNu = [0.02 + 0.078e~((-Q/0.72))]Ra_(El)~(0.68), is applicable over a range of electric Rayleigh Numbers from 6x10~3 to 3x10~6 and heat fluxes from 0.5kw/m~2 to 3.5kw/m~2.