An experimental investigation on effects of an electric field on bubble growth on a small heater in pool boiling

EHD effects on bubble nucleation and its subsequent growth dynamic on a small heater in pool boiling of R113 are investigated experimentally in this paper. The small heater, 5 mm x 5 mm in size, is made of an ITO film consisting of Pyrex glass and ITO-coatings. A non-uniform electric field is generated by a vertical needle at high potential and the small heater at low potential as electrodes. A high-speed camera is used to record the changing shape of a single R113 vapor bubble during its nucleation and its subsequent rise from the small heater at different heat fluxes with and without an externally imposed electric field. Effects of electric field strength and imposed heat flux on the bubble growth time, waiting time, departure frequency, dynamic contact angle and movement of triple contact line are presented. It is found that the electric field enhances nucleate boiling heat transfer of a single R113 bubble in the present experiment. (C) 2013 Elsevier Ltd. All rights reserved.