Surface Hydrophobicity and the Dynamics of Contact Lines
Abstract
The contact line (the intersection between water, air, and a surface) is an important aspect of flow around ships, affecting spray generation, and resistance. Studying ways to modify the contact line can thus lead to the development of methods to reduce resistance on ships and control the spray signature of vessels. The proposed work will study the dynamics of contact lines perturbed by modulations in wetting properties. Three projects are proposed: the first is exploring air entrainment by the dynamic contact line on surfaces with alternating bands of hydrophobic and hydrophilic regions. Such air entrainment can shed light on a potential source for the deep-water bubbly flow beneath ships, which affects the long wake signature behind the vessel. The second project is the generation of side forces by introducing patterned wetting properties on only one side of a surface-piercing object. The asymmetric wetting conditions on either side of the object could lead to asymmetric force generation. Applying the idea to vessels could reduce a ship’s need to zig-zag in oblique seas and could potentially ease maneuverability during turns. The last proposed project is studying the effects of patterned wetting properties on sheet breakup and spray generation. Spray increases the visibility of ships at sea, thus studying ways to modify sheet breakup and spray generation could lead to novel approaches for changing a vessel’s signature.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 08, 2016
- Source ID
- N000141512479
Entities
People
- Morteza Gharib
Organizations
- California Institute of Technology
- Office of Naval Research
- United States Navy