Electrohydrodynamic Induction Pumping of Liquid Film in Vertical Annular Configuration

Electrohydrodynamic (EHD) induction pumping of two-phase medium is attractive for terrestrial and outer space applications, since it is nonmechanical, lightweight, and involves no moving parts. In addition to pure pumping purposes, EHD induction pumps are also used for the enhancement of heat transfer, as an increase in mass transport often translates to an augmentation of the heat transfer. Applications include two-phase heat exchangers (evaporators and condensers), heat pipes, and capillary pumped loops. A theoretical model for the EHD induction pumping of an annular liquid/vapor medium where the charges are induced at the two-phase interface as well as within the bulk of the liquid phase in a vertical configuration is presented. The dimensionless numerical results are obtained, and the flow physics are discussed in conjunction with the effect of the controlling parameters. The controlling parameters include the following: liquid-film thickness, voltage, wavelength, frequency, external pressure, and gravity.