Effect of heterogeneous wettable structures on pool boiling performance of cylindrical copper surfaces

In this work, pool boiling heat transfer experiments were conducted to investigate the effect of the heterogeneous wettable surfaces. Three different types of heterogeneous wettable surfaces were produced by printing the polymethyl methacrylate (PMMA) polymer on the plain copper and the hydrophobic polymer on the plain copper and superhydrophilic surface. The heat transfer experiments were conducted on a hollow copper cylinder of 25 mm outer diameter and 40 mm long, with de-ionized (DI) water as the working fluid. The effect of heterogeneous wettability on the boiling bubble dynamics, heat flux, surface temperatures and the average heat transfer coefficient (HTC) were investigated at the saturated conditions. An appreciable enhancement of 98.5% in the HTC was observed on the hydrophobic polymer printed plain copper sample as compared to the plain copper, at a lower heat flux of 15 kW/m(2). (C) 2017 Elsevier Ltd. All rights reserved.