Accession Number : AD1031055


Title :   Hydrodynamic Drag Force Measurement Of A Functionalized Surface Exhibiting Superhydrophobic Properties


Descriptive Note : Technical Report


Corporate Author : Naval Postgraduate School Monterey United States


Personal Author(s) : Ley,James R


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/1031055.pdf


Report Date : 01 Dec 2016


Pagination or Media Count : 77


Abstract : With superhydrophobic properties being extended to a variety of metallic substrates through the process of ablation due to femto-second laser surface processing (FLSP), it is important to understand the hydrodynamic benefits of such a material, as well as its resiliency. This research will focus on the skin friction drag effects of a superhydrophobic flat plate compared to an untreated flat plate of the same material and geometry. The resiliency of this material will also be tested through the use of an accelerated corrosion fog chamber using both treated and untreated aluminum samples. During complete submersion water channel testing, the velocity of the water was varied to yield a range of Reynolds numbers between 20,000 and 70,000 with respect to the test specimen. In this range, the FLSP treated plate showed consistently lower skin friction drag than that of the untreated plate. However, during the accelerated corrosion testing, the FLSP treated sample suffered from pitting corrosion at a rate faster than the untreated sample, effectively removing the surface treatment. While there are significant hydrodynamic benefits to this material, the elevated corrosion rates raise concerns about the resiliency of this surface treatment.


Descriptors :   surface properties , hydrophobic properties , skin friction , surface chemistry , HYDRODYNAMICS , drag


Subject Categories : Fluid Mechanics


Distribution Statement : APPROVED FOR PUBLIC RELEASE