Molecular dynamic simulation of rapid boiling of nanofluids on different wetting surfaces with depositional nanoparticles

摘要

In this paper, the effects of depositional nanoparticles on the surface wettability of nanofluids during rapid boiling are investigated by molecular dynamics simulation to reveal the enhancement mechanism of depositional nanoparticles on boiling heat transfer. In four wetting-surface cases, the contact angle changes of a droplet with and without nanoparticles were analyzed. Because we knew that the contact angle was related to surface wettability, and a droplet with nanoparticles showed a smaller contact angle, the surface wettability was improved by the addition of nanoparticles. To confirm the accuracy of this statement, the rapid boiling behaviors of a base fluid and a nanofluid were simulated to investigate the influence of depositional nanoparticles on surface wettability, thereby revealing the effect mechanism of depositional nanoparticles in nanofluids upon boiling. The results indicated that rapid boiling occurred faster in nanofluids. The depositional nanoparticles in nanofluids improved the surface wettability, which increased the heat transfer rate between the surface and the liquid, thereby providing more favorable conditions for rapid boiling compared with those of a base fluid. (C) 2019 Elsevier Ltd. All rights reserved.