Electrohydrodynamic Condensation Heat Transfer

Abstract

This paper describes the results of an investigation of the effects of strong electric fields on condensation heat transfer. Freon-113 is condensed inside a vertical tube, and the condensate interface is stressed by a radial d-c field. The effect of the field on condensing heat transfer can be summarized as follows: (a) The condensing heat transfer coefficient increases significantly with the electric field; (b) the increase is related to the appearance of instability waves at the liquid film interface. These effects suggest that the average liquid film thickness is significantly reduced at high electric field intensities. A tentative correlation is presented for the high field data. The correlation is presented in terms of modified Nusselt and Rayleigh numbers in which the characteristic length is the most unstable wavelength in the system, and the driving force acting on the film is an equivalent electrohydrodynamic force.