Numerical Study of Dielectric Fluid Bubble Behavior in Microchannel Evaporator in Presence of Diverging Electric Field

Abstract

Herein, the diverging dielectrophoretic (DEP) electrode is designed to extract the vapor bubbles generated in a flow-boiling evaporator. The DEP and hydrodynamic forces acting on the undeformable single vapor bubble in the diverging electrode are estimated by the uncoupled flow and electrostatic simulation. The Maxwell stress, static pressure, and viscous shear stress on the bubble surface are considered. The diverging DEP electrode successfully generates a net force that acts on the bubble in the flow direction. The DEP force is dominant against drag at a low imposed mass flux and high applied electric field, where heat transfer enhancement could be expected. A large DEP force pushing the bubble toward the electrode is found when the bubble is close to the electrode.