Skin friction drag reduction in turbulent flows using superhydrophobic surfaces
Name
1023497729-MIT.pdf
Description
Full printable version
Size
12.44 MB
Format
Adobe PDF
Checksum (MD5)
eeac527d401cf690644aee3b1dc1af23
Author(s)
Rajappan, Anoop
Advisor(s)
Gareth H. McKinley.
Date Issued
2017
Publisher
Massachusetts Institute of Technology
Abstract
The use of randomly textured superhydrophobic surfaces have recently gained interest as a potential approach for the passive reduction of skinfriction on the hull of ships, submarines and underwater projectiles. When submerged in water, these surfaces trap a layer of air (or 'plastron') within their texture, which allows the external fluid to partially slip over the boundary, decreasing the net frictional shear stress on the wall. Five prototype drag-reducing surfaces were evaluated experimentally as possible candidates for turbulent drag reduction applications, using a combination of flow tests, surface profile measurements, and contact angle goniometry. Three of these were randomly rough superhydrophobic textures, produced by easily scalable mechanical and chemical surface treatment processes; the other two surfaces consisted of periodic streamwise grooves, filled with air or a low viscosity liquid lubricant. The skin friction characteristics of all five prototype surfaces were measured in fully turbulent flow inside a custom-built Taylor-Couette apparatus for Reynolds numbers in the range 1.64 x 104
Description
Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2017.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 127-136).
Subjects
Mechanical Engineering.
MIT Department
Massachusetts Institute of Technology. Department of Mechanical Engineering
Terms of Use
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