The sea-water that flows over a ship hull forms a turbulent boundary layer that is responsible for the skin-friction drag incurred by the ship. This boundary layer is influenced by the "roughness'' of the hull surface, which increases the drag penalty by up to 80% compared to a smooth surface in some applications. This highlights the urgent need to understand the "roughness'' effects of surface coatings and their degradation on the efficiency, economy and emissions of ship transportation. In this project, we propose a transformative approach where we tackle this pressing problem using three complementary methods. First, we will carry out Direct Numerical Simulations (DNS) of turbulent flow over surfaces that have been obtained from surface scans of various ship hulls. These results will be complemented by laboratory experiments and measurements in a towing tank of flows over replica of the same scanned surfaces. Finally, a DNS-Embedded Large Eddy Simulation (DELES) methodology will be developed and used to predict the influence of realistic topographies on drag.This holistic approach will provide the necessary data to gain fundamental understanding of the flows over such rough surfaces and enable development of a new data-rich paradigm for predicting the effects of roughness. We will specifically focus on maritime transport by developing a new surface-specific Moody-diagram approach that can be used by coatings manufacturers and ship operators to generate a realistic estimate of the drag penalty of coatings and fouling. This information can then be used to make operational decisions such as duration between dry-docking, quality of surface finish when in dry-dock, choice of specific coatings for specific surface finish and the variations in performance during service. This new approach can easily be extended to different sectors and new surface-specific Moody-diagrams can be developed for a whole range of applications including oil, gas and water transport pipelines, aircraft fuselage, trains, propellers etc. This project has financial support from a leading antifouling coatings manufacturer as well as collaborators at the University of Melbourne and the US Naval Academy who share our mutual interest in this research area.

Our vision is to create an enduring, multidisciplinary and independent research community strongly linked to industry and capable of informing the policy making process by developing new knowledge and understanding on the subject of the shipping system, its energy efficiency and emissions, and its transition to a low carbon, more resilient future. Shipping in Changing Climates (SCC) is the embodiment of that vision: a multi-university, multi-disciplinary consortium of leading UK academic institutions focused on addressing the interconnected research questions that arise from considering shipping's possible response over the next few decades due to changes in: - climate (sea level rise, storm frequency) - regulatory climate (mitigation and adaptation policy) - macroeconomic climate (increased trade, differing trade patterns, higher energy prices) Building on RCUK Energy programme's substantial (~2.25m) investment in this area: Low Carbon Shipping and High Seas projects, this research will provide crucial input into long-term strategic planning (commercial and policy) for shipping, in order to enable the sector to transition the next few decades with minimum disruption of the essential global services (trade, transport, economic growth, food and fuel security) that it provides. The ambitious research programme can only be undertaken because of the project's excellent connection to shipping's stakeholders across the govt. non-govt and industry space. This is demonstrated by in excess of 35 organisations writing significant statements of support and including contributions to the project of 1.6m in-kind and 160k cash. The commitments of stakeholders with this breadth of knowledge and understanding is crucial both to: - Development of a relevant proposal (all Tier 1 partners of LCS and many Tier 2 and others were heavily involved in the development of the contents of this SCC proposal) - Ensuring that the research is undertaken using data and experience that can maximise its credibility, but importantly also - Guaranteeing a direct pathway to impact in all the key governance and commercial stakeholders of the sector. Shipping is a global industry and its challenges must therefore be considered in a global context. However, to provide focus for the research we will concentrate the application of our global modelling and analysis for understanding the impacts of changing climates on three key specific sub- global components of the system: UK, SIDS (Small Island Developing States) and BRICS shipping. The UK, for its importance to the funder and the UK stakeholders engaged in our project, the BRICS and SIDS because of their central role in the policy debate due to their high sensitivity to changing climates Research Excellence will be ensured through research across three interacting research themes: - ship as a system (understanding the scope for greater supply side energy efficiency) - trade and transport demand (understanding the trends and drivers for transport demand) - transitions and evolution (understanding transport supply/demand interactions) The research undertaken will be both quantitative and qualitative, apply for the first time new data and modelling techniques and be deployed to answer a series of cross cutting (themes) research questions. Shipping in Changing Climates will put the UK at the forefront internationally of research into the shipping system and inform the UK and EU debates around the control of its shipping GHG emissions.