Effect of mixed wettability surfaces on droplet evaporation and flow boiling

Official URL: https://risc01.sabanciuniv.edu/record=b2708506_(Table of contents)

Global demand on energy efficiency, along with recent concerns about greenhouse effect, has motivated researchers to conduct studies on the heat transfer performance of heat exchangers. Among the new methods proposed by the researchers, surface modifications have shown promising results in phase-change heat transfer, including flow and pool boiling, flow condensation, as well as droplet evaporation. In this thesis, the effect of surface biphiliciy on flow boiling and droplet evaporation was investigated. The experimental results revealed that the biphilic surfaces are capable of enhancing the heat transfer up to 40% in droplet evaporation experiments, while up to 50% enhancement was obtained in flow boiling experiments. Moreover, using biphilic surfaces, evaporation dynamics of high aspect ratio elongated droplets was investigated. In the light of the experimental results, a fully coupled algorithm was developed which considered all the instabilities in the both liquid and gas phases. The algorithm is later used to study the effect of adjacency on evaporation dynamics of high aspect ratio water droplets.