Experimental investigation of the eect of one-dimensional roughened surface on the pool boiling of nano uids

This research is aimed at developing a particular surface for promoting nucleate boiling heat transfer characteristics, reducing the superheat temperature and postponing the occurrence of critical heat ux to the long term. To this end, a laboratory apparatus was built. In order to feed the microlayer of bubble more through the capillary force of micro-grooves, the boiling surface was roughened in one direction. Although the boiling characteristics of roughened surfaces were more enhanced than those of the polished surface, the results were not very impressive. Although the boiling of two nano uids, i.e., copper oxide and alumina, on the micro-groove surface resulted in a signicant increase in the nucleate heat transfer coecient, this method cannot be applied to a process with a long computational time because of continuous deposition of nanoparticles over time and creation of an insulation layer on the micro-groove surface. Therefore, simultaneous utilization of micro-groove surface and deposition of a thin and porous layer of nanoparticles on the surface increased the feeding of sites and production of bubbles, respectively. The critical heat ux and boiling heat transfer coecients of the surface deposited with copper oxide nanoparticles were enhanced by 46.5% and 74.2%, respectively.