FEIT Research Project Database

The effect of non-homogeneous roughness on full-scale drag predictions

Project Leader: Nicholas Hutchins
Staff: Jason Monty, Kevin Kevin
Collaborators: Haoliang Chen (AkzoNobel) Professor Mike Schultz (US Naval Academy)
Sponsors: ARC, AkzoNobel
Primary Contact: Nicholas Hutchins (nhu@unimelb.edu.au)
Keywords: drag reduction; fluid mechanics; maritime engineering; turbulence
Disciplines: Mechanical Engineering

Partnering with AkzoNobel, one of the world’s leading suppliers of anti-fouling marine coatings, this project will deliver new tools for predicting the drag penalty on ships fouled by the settlement of marine organisms on the hull. All currently available predictions assume a homogeneous distribution of roughness. Yet we know biofouling is always patchy, hence prediction methods need an upgrade. Making a compelling business case to ship operators is contingent on such predictions, where the cost of anti-fouling solutions is weighed against that of continued operation with a rough hull. The novel tools developed here will therefore lead to increased ship efficiency by empowering ship operators to optimise hull cleaning and repainting schedules.

We are currenty recruiting PhD students and postdoctoral researchers to work on this project. The work will entail making detailed measurements in the turbulent boundary layers formed over various patchy (heterogeneous) surface arrangements. These measurements will be preformed in the high Reynolds number boundary layer wind tunnel (HRNBLWT), a large-scale facility with a 27 m long working section located in the Walter Bassett Aerodynamics laboratory at the University of Melbourne (https://mechanical.eng.unimelb.edu.au/research/fluid-mechanics/walter-bassett). Surface scans of actual fouling topograghies will be obtained during underwater dive inspections and during dry-docking at our partner's facilities. Replicated and scaled surfaces surfaces from these scans will be tested in smaller scale boundary layer wind-tunnels.

In-house developed under-water surface scanner, for capturing the surface topography of fouled hulls.
Schematic of proposed heterogeous rough-wall turbulent boundary layer measurements in the HRNBLWT facility.