An Seongpil, Lee Changmin, Liou Minho, Jo Hong Seok, Park Jung-Jae, Yarin Alexander L, Yoon Sam S
School of Mechanical Engineering, ‡Green School, and §College of Engineering, Korea University , Seoul 136-713, Republic of Korea.
ACS Appl Mater Interfaces. 2014 Aug 27;6(16):13657-66. doi: 10.1021/am503139n. Epub 2014 Jul 28.
The effect of the supersonically blown below-74 nm nanofibers on cooling of high-temperature surfaces is studied experimentally and theoretically. The ultrathin supersonically blown nanofibers were deposited and then copper-plated, while their surfaces resembled those of the thorny-devil nanofibers. Here, we study for the first time the enhancement of surface cooling in gas in the cases of the forced and natural convection with the help of ultrathin thorny-devil nanofibers. These polymer core-metal shell nanofibers in nanometric scale possess a relatively high thickness of the metal shell and a high effective thermal conductivity, which facilitates heat transfer. The additional surface temperature reduction close to 5 °C in the case of the forced convection in the impinging air jet and close to 17 °C in the case of the natural convection was achieved. Correspondingly, an increase in the value of the heat transfer coefficient of about 41% in the forced convection, and about 20% in the natural convection was achieved due to the presence of the thorny devil electrospun and/or supersonically blown nanofibers.
