Effect of a dc electric field on the liquid-vapor interface in a grooved flat heat pipe

Abstract

In this communication, a grooved flat plate heat pipe is considered with an electric field applied between the top and bottom plates of the heat pipe. In this way, a dielectric force arises, which aims at pumping the liquid phase together with the capillary force. The ability of the electric field to change the shape of the liquid-vapor interface is theoretically investigated by a numerical approach. This approach consists in the strong coupling between the Laplace-Young equation, extended with the electric stress, and the Poisson equation for the electric potential. The former is used for the calculation of the shape of the liquid-vapor interface while the latter is solved for the determination of the electric stress along the interface. The results show that the electric field can extend the capillary limit of the heat pipe by increasing the maximum curvature of the liquid-vapor interface before the meniscus recession. This effect is even greater than the electric pumping effect for non-wetting fluids. A final discussion is presented to highlight the configurations for which the use of an electric field yields significant improvements to the performance of a grooved flat plate heat pipe.