Controlling bubble motion over heated surface through evaporation momentum force to enhance pool boiling heat transfer

Evaporation momentum force arises due to the difference in liquid and vapor densities at an evaporating interface. The resulting rapid interface motion increases the microconvection heat transfer around a nucleating bubble in pool boiling. Microstructure features are developed on the basis of this hypothesis to control the bubble trajectory for (i) enhancing the heat transfer coefficient, and (ii) creating separate liquid and vapor pathways that result in an increased critical heat flux (CHF). An eightfold higher heat transfer coefficient (629 000 W/m(2)degrees C) and two-and-half times higher CHF (3 MW/m(2)) over a plain copper surface were achieved with water. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4791682]