Condensation and subsequent freezing delays as a result of using femtosecond laser functionalized surfaces

Authors

Chongji Huang, University of Nebraska-LincolnFollow
Ryan Bell, University of Nebraska-Lincoln
Alfred Tsubaki, University of Nebraska-LincolnFollow
Craig Zuhlke, University of Nebraska-LincolnFollow
Dennis Alexander, University of Nebraska - LincolnFollow

Date of this Version

2-2018

Citation

JOURNAL OF LASER APPLICATIONS, VOLUME 30, NUMBER 1, FEBRUARY 2018

doi:10.2351/1.4986058

Comments

Copyright 2018 Laser Institute of America

Abstract

In this paper, the authors report on the use of femtosecond laser surface processing (FLSP) to enhance the anti-icing properties of a commonly used aircraft alloy, Al 7075-O Clad. By changing the surface morphology through FLSP and the surface chemistry through siloxane vapor deposition, the wettability of Al 7075-O Clad was altered. Tall mound and short mound FLSP functionalized surfaces were created through two sets of laser parameters. Condensation and the subsequent freezing of condensates on FLSP Al 7075-O Clad was studied. Both structure height and surface wettability were shown to play a role in the delay of freezing. Freezing occurred on the FLSP superhydrophilic surface faster than on the unprocessed Al 7075-O Clad surface; however, freezing was delayed for all superhydrophobic FLSP surfaces. Tall structure height FLSP functionalized surfaces delayed freezing time longer than short structure height FLSP functionalized surfaces although all were superhydrophobic. It was shown that FLSP functionalized surfaces were able to delay freezing by up to 530 s compared with unprocessed Al 7075-O Clad. The authors also report on self-propelled condensate jumping on FLSP surfaces during the condensing process. The selfpropelled jumping phenomena provide a means to promote anti-icing of materials, especially where jumping drops can be swept away in flow conditions.