Enhancement of heat and mass transfer by an electric field

Issues of the enhancement of the heat and mass transfer processes under the action of electric fields are discussed. The homogeneous liquids under study are subdivided into two classes-ideal dielectrics and weakly conductive ones-depending on the ratio of the medium's relaxation time to the external field's oscillation period. In the case of heat transfer in heterogeneous systems, the media are considered in which the relaxation time of the dispersion phase is less than that of the confined phase. In regard to the phase separation processes, the relaxation times of the phases are arbitrary; the confined phase, however, must be either dielectric or weakly conductive. Some aspects of electrization of weakly conductive liquids and the convection phenomena in them-the thermal, mechanical, and those induced by the electric field itself-are analyzed in dependence on the inhomogeneity of the medium in terms of its electric relaxation time. The experimental data on the heat and mass transfer with reference to the condensation processes under the corona discharge and to the electrical purification are classified and generalized. In addition, the process of the heat transfer from a heated surface to a magnetic liquid is investigated and the results are discussed. It is stated that many processes can be treated in physical terms using the concept of a corona discharge.