Pool Boiling Heat Transfer Enhancement through Biphilic Stepped Microchannel

Abstract

In present study, pool boiling heat transfer (PBHT) from biphilic stepped microchannel comprising: hydrophobic fin top and hydrophilic channel region is investigated. The biphilic stepped microchannel is prepared by mechanical polishing and thermo-catalytic etching. The improved liquid supply pattern, increased nucleation site density, retarded bubble coalescence between the adjacent channel and decreased wall forces acting on the bubble meniscus resulted in the PBHT enhancement. Contact angle of the water droplet on hydrophobic and hydrophilic surface is 74.02° and 22.5°, respectively. Enhancement in critical heat flux and heat transfer coefficient by the biphilic stepped microchannel is 195.52% and 367.00%, respectively.