The hydrodynamics lab pioneering offshore renewable energy innovation

Together, and as part of wider consortia, the Manchester research team is supporting development of systems for power generation from farms of tidal stream turbines and of wave energy devices. 

The new hydrodynamics lab completed earlier this year as part of the Manchester Engineering Campus Development is designed to provide a unique environment – of waves co-existing with a shallow turbulent flow – to advance understanding needed for design of floating offshore wind platforms, wave energy devices and tidal stream turbines.

The design of the main test facility is based on an earlier test basin, now decommissioned, which underpinned research by the team on the performance and interaction of tidal stream turbines in arrays and on wave energy system development. This features a 20 m long x 5 m wide wave channel up to 0.8 m deep with force-feedback wave generators providing directionally spread wave fields.

In addition, underfloor provides an opposing turbulent channel flow of up to 0.5 m/s enabling scale testing. Lab instrumentation includes a range of surface- and velocity measurement devices, motion capture for floating structures and high-speed cameras. The laboratory also contains multiple smaller flumes employed to analyse waves- and flows- in isolation and used for teaching on undergraduate programmes such as civil and mechanical engineering.

Underfloor provides an opposing turbulent channel flow of up to 0.5 m/s enabling scale testing. Lab instrumentation includes a range of surface- and velocity measurement devices, motion capture for floating structures and high-speed cameras

The lab conditions enable the researchers to represent real-world environments. Recent experimental studies by Dr Sam Draycott focus on the wave conditions that define peak loading of offshore structures. Live projects by the wider team address mooring design for floating platforms, prediction of turbine loads due to waves and turbulent flow, and characterisation of wakes to enable accurate prediction of energy yield of large wind farms and tidal stream farms.

Reduced-scale experiments inform the development of modelling tools and are undertaken in parallel with studies of data from offshore sites. Work on tidal stream systems has included the recently completed EU Interreg TIGER project on which we have undertaken analysis of multiple field measurements from the major tidal-stream site Raz Blanchard. We are now beginning a project with tidal site stream developer MeyGen to advance understanding of flow conditions at this site at which projects of 50 MW are in development funded by the UK government CfD scheme.

Complementing these industrially supported projects has been the award of a five year  Dame Kathleen Ollerenshaw Fellowship [to Hannah Mullings] to advance understanding of turbulent tidal flows at a reduced scale, with the longer term goal of increasing confidence in design by reducing uncertainty in offshore conditions at highly energetic tidal sites. Part of this work will further develop turbulence generation methods in order to better represent offshore conditions for testing and extend the capabilities of the new facility.

Whilst many offshore wind turbines are now installed globally, significant expansion is expected into deeper waters for which floating offshore wind platforms are required.  We’re researching how to control the platform motion, by integration of aerodynamic control of the turbine with coupled hydrodynamic and structural models. Methods such as water pumping between the multiple columns of offshore platforms are also being explored to stabilise movement for operations and maintenance, and to minimise fatigue and structural damage.

Ultimately, the research and activities by the team, and in the lab, aim to support sustainability. Diversifying our sources of energy is important to transition, and also supports energy security

Another area of focus in the new hydrodynamics lab is wave energy. Unlike wind and tidal energies, which have largely adopted standardised designs like the three-bladed turbines, wave energy lacks a converged design.

We are using our facilities and modelling expertise to undertake world-leading research to deliver efficient solutions to these areas. Small-scale testing of innovative wave energy devices performed in the lab have led to testing in larger facilities, and offshore trials of a large-scale demonstration device are planned for later this year in Australia.

Educating and sustaining

Our team conducts research as part of a long-term and broader goal to enhance development of technologies for generation of power from Offshore Renewable Energy resources.  Team members are part of the leadership of the EPSRC Supergen Offshore Renewable Energy Impact Hub (2018-2027) which brings together 10 UK universities working in this field and also supports early career researcher development.

The team has connected with the University of Manchester's Science and Engineering Education Research and Innovation Hub (SEERIH), which is a nationally recognised centre of science and engineering education. Planning is currently in place to support a masterclass for primary school children and their teachers on sustainable energy where they will get the opportunity to visit the lab and learn about the research conducted at Manchester and the industry that we support.

Ultimately, the research and activities by the team, and in the lab, aim to support sustainability. Diversifying our sources of energy is important to transition, and also supports energy security. Our work at the Manchester Hydrodynamics Lab – and throughout our networks – helps to support this transition to a more sustainable future.

Dr Hannah Mullings is a research fellow and Tim Stallard is professor of Offshore & Renewable Energy Engineering at the University of Manchester