Heat transfer from a wire to hexane in a nonuniform electric field

The influence of a nonuniform electric field (ac or dc) on heat transfer from an electrically heated platinum wire immersed in n‐hexane was investigated. The platinum wire was concentrically mounted in a closed copper cylinder filled with the test liquid. The copper cylinder was placed horizontally in a constant temperature bath. Heat transfer coefficients for natural convection were obtained to serve as a reference for the electric field measurements. The electric field results showed an increase in the heat transfer rate from the wire over free convection for both ac and dc fields. The electric Nusselt numbers in ac fields were a factor of 4 higher than corresponding results in dc fields. This behavior differed from results reported in the literature for n‐hexane, which was further demonstrated by replotting some of the raw data using the same physical and electrical properties employed to reduce the present experimental data.