Engineering of surfaces for drag reduction in water with validation using computational and experimental methods
Lead Research Organisation:
University of Southampton
Department Name: Faculty of Engineering & the Environment
Abstract
Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.
Organisations
Publications

Busse A
(2012)
Influence of an anisotropic slip-length boundary condition on turbulent channel flow
in Physics of Fluids

Busse A
(2013)
Change in drag, apparent slip and optimum air layer thickness for laminar flow over an idealised superhydrophobic surface
in Journal of Fluid Mechanics

Busse A
(2012)
Parametric forcing approach to rough-wall turbulent channel flow
in Journal of Fluid Mechanics

Busse A
(2011)
Simulation of rough wall turbulent channel flow using a parametric forcing approach
in Journal of Physics: Conference Series

Gruncell B
(2013)
Simulations of laminar flow past a superhydrophobic sphere with drag reduction and separation delay
in Physics of Fluids

Thakkar M
(2017)
Direct numerical simulation of turbulent channel flow over a surrogate for Nikuradse-type roughness
in Journal of Fluid Mechanics
Description | The project has led to new understanding of the potential for drag reduction using surface treatments that produce an effective slip of fluid flow over a surface. The project contained both experimental and numerical simulation components. An experimental technique was developed to give excellent repeatability for towing tank experiments. A test plate holder was designed and manufactured, capable of testing sample surfaces with good control over transition to turbulence. Significant drag reductions were obtained comparing wetted to unwetted samples. For full details the reader is referred to the PhD thesis of Gruncell (2014). Simulation work considered models for the roughness necessary to retain the air layer in practice and the type of anisotropic surface slip that is most effective at giving drag reduction. Additional theoretical work showed the influence of different assumptions in the air layer, in particular a zero net mass flux, which may be a more realistic model for practical application. The reader is referred to the publications (Busse et al) that discuss the simulation and theoretical work in more detail. |
Exploitation Route | Surfaces with demonstrated drag reduction using superhydrophobic surfaces are of particular interest in the marine sector as surface coatings. The advantages of generating partial slip have been demonstrated in calculations of flows using a Navier-slip boundary condition (with non-isotropic surface characteristics) and with a full representation of the two-phase flow. Experiments have demonstrated drag reduction comparing superhydrophobic and wetted states and the important influence of roughness that protrudes through the surface air layer has been demonstrated. A test facility is now available for future work and commercial testing (contact the Wolfson Unit in Southampton). |
Sectors | Aerospace Defence and Marine Energy Environment Transport |
URL | http://www.southampton.ac.uk/engineering/about/staff/nds9.page |
Description | The potential for drag reduction with hydrophobic treatment for specific rough surfaces was demonstrated, although not an absolute drag reduction relative to smooth surfaces. This is guiding future research. We also alerted the research community to specific limits on the drag reduction that can be attained when fixed mass flow in the air layer is set. |
First Year Of Impact | 2013 |
Sector | Aerospace, Defence and Marine,Energy |