Analysis of the polarity influence on nucleate pool boiling under a DC electric field

An experimental study of the action of an intense electric field on the poo l boiling of n-pentane is presented. By the application of a 25 kV/cm elect ric field strength, a threefold hear transfer enhancement is obtained The e ffect of the electric field polarity has been researched. In nucleate boili ng, the negative polarity allows to obtain a heat transfer enhancement, whi ch is better than the one obtained in positive polarity. However; in natura l convection and near the critical heat flux, the polarity of the electric field has a low influence on the heat transfer The interpretations of the o bserved results are based on the action of the electric field on the boilin g phenomenon and more particularly on the analysis of the electric field di stribution between the electrodes. The influence of the space charge inject ion and the effect of the temperature on the electric field distribution ha ve been investigated. The results obtained in the two cases of polarity are discussed in terms of effects of electrical and thermal phenomena on the d istribution of the Electric field between the electrodes.