An experimental investigation on the developing wavy falling film in the presence of electrohydrodynamic conduction phenomenon

Hydrodynamic behavior of developing laminar wavy falling film has been studied, experimentally, in the presence of electrohydrodynamic conduction phenomenon. Electric field has been applied using nine pairs of flush mounted electrodes which can generate an EHD conduction pumping effect in the liquid film. Statistical characteristics of wavy falling film have been extracted and the effect of EHD conduction phenomenon on the wavy falling film behavior has been investigated in various Re numbers and applied voltages for two different inclination angles. Furthermore, two different operation cases for conduction pumps have been considered. The results show that applying of electric field on falling film using flush mounted electrodes, which does not alter the flow geometry and film original structure, can intensify the wavy behavior of laminar falling film. This effect is considerable for high Reynolds numbers in which large waves appear on the film surface. Comparison of operation cases show that the case with narrower high voltage electrode decreases the substrate thickness and can be the better choice for enhancement of heat/mass transfer.