Experimental Study of a Two-Phase Heat Transport Device Driven by Electrohydrodynamic Conduction Pumping

Abstract

Heat pipes are well-known as simple and effective heat transport devices, utilizing two-phase flow and the capillary phenomenon to remove heat. However, the generation of capillary pressure requires a wicking structure and the overall heat transport capacity of the heat pipe is generally limited by the amount of capillary pressure generation that the wicking structure can achieve. Therefore, to increase the heat transport capacity, the capillary phenomenon must be either augmented or replaced by some other pumping technique. Electro-hydrodynamic (EHD) conduction pumping has been demonstrated as an effective method for pumping liquid films by using DC electric fields and a dielectric working fluid. Beyond increased pumping capacity, EHD conduction pumping offers other advantages over capillary pumping, such as active control of the pumping capacity via the intensity of the applied electric field. This experimental study demonstrates the prospects of a macro-scale two-phase heat transport device that is driven by EHD conduction pumping. Various liquid film thicknesses are considered. In each case, the performance of the EHD-driven heat transport device at various electric field intensities is compared to the capabilities of the same device under gravity alone. The effect of tilt on the device is also considered.