This project aims to develop a bio-inspired morphing blade to mitigate the unsteady loading of wind and tidal turbines, improving resilience and reliability, and decreasing the levelised cost of energy.
BACKGROUND. Wind and tidal energy are some of the most promising contenders for enabling the UK to meet its 2050 target of reducing greenhouse gas emissions by 80% from 1990 levels. Europe, and the UK within Europe, is world leader in offshore wind and tidal research and device development. The world’s first arrays of both floating offshore wind (Peterhead, 2017) and tidal turbines (Meygen and Nova’s Bluemull Sound, 2016) have now been deployed in Scotland. Hence, it is timely for the UK to become global leader in the manufacture and supply chain of key components in these emerging sectors. The wind and tidal industries are at different stages of development, but for both these sectors to develop further, they need new technology to be developed to address some common challenges. By enabling more reliable, cheaper and larger wind and tidal turbines to be built, this project will contribute to providing more competitive renewable energy. This, in turn, will strengthen the resilience of the UK and will help the UK to maintain its position as world leader in the field of marine renewable energy research.
THE CHALLENGE OF UNSTEADY LOADING AND POWER FLUCTUATIONS. The large flow fluctuations induced by the shear and turbulence of the onset flow, yaw misalignment, interaction with the support structures, and wakes of the upstream devices are a major challenge to the design of both wind and tidal turbines. In addition, flow fluctuations of wind turbines are set to further increase due to the scale up to larger turbines that leads to slimmer and more flexible blades. The increasing cost of individual offshore platforms might lead to multiple rotors on the same platform, resulting in high interference between turbines. Turbine interference is likely to increase also in the tidal sector, where interference could be exploited to increase yields. Tidal turbines also experience extreme load fluctuations due to the effect of ocean waves. In both these industry sectors, flow fluctuations result in vibrations transmitted from the blades to the rest of the turbine making fatigue failures a key limit to reliability. Secondly, unsteady loadings are reflected into power output fluctuations, which result in over-dimensioned power-take-off systems. Ultimately, this increases the levelised cost of energy (LCoE), which is the average minimum price at which electricity must be sold in order to break-even over the lifetime of the project.
AIMS AND OBJECTIVES. This project aims to develop a new-concept blade for both wind and tidal rotors, that mitigates the unsteady loadings by adapting its shape to load fluctuations. This technology exceeds the performance of active systems such as pitch control, with the simplicity and reliability of passive systems such as hydroelastic tailoring. Our previous work shows theoretically that load fluctuations can be almost canceled, including the highest frequency fluctuations. Blades are equipped with a flexible trailing edge, whose flexibility and initial shape varies along the blade span. When the fluid velocity varies, the trailing edge passively changes shape mitigating the load fluctuation. The deformable trailing edge has a fraction of the inertia of the full blade and, hence, it can react to high-frequency fluctuations. In addition, differently from existing technology that only acts on the sections nearer to the tip, load fluctuations are mitigated at every section of the blade along the span. This results in a cleaner wake and more energy available to the downstream turbines.
RESEARCH ENVIRONMENT. The student will join the CDT in Wind and Marine Energy Systems and Structures, which is jointly led by the Universities of Edinburgh, Oxford and Strathclyde. As part of the CDT, the student will attend specialist courses from October to February and will start the research project from February. She/he will be based within the Institute for Energy Systems (IES) of the School of Engineering at the University of Edinburgh. IES is a world-leading multi-disciplinary research institute with a strong focus on offshore renewable energy. It includes more than 20 staff, 20 PDRAs and 50 PhD students. Between 2003 and 2018, IES has hosted the UK Centre for Marine Energy Research (UKCMER) and since 2017 it hosts the Centre for Advanced Materials for Marine Energy Generation (CAMREG). This PhD project bridges the two centers and complements one of the two SUPERGEN Marine projects on unsteady hydrodynamics of tidal turbines led by IES (FloWTurb, EP/N021487/1). IES is the founder and chair of the Ocean Energy Group within the European Energy Research Alliance, which will provide international links and accelerate the impact of the project.
The student will join the Vortex Interaction Collaboratory (VOILAb), whose research in vortex-dominated flow is internationally renowned. The group, led by Ignazio Maria Viola, is made of about six PhD students and four postdocs, including CDT students G. Pisetta and A. Pavar. Previous work on morphing blades at VOILAb underpinned a £1.1M project funded by the EPSRC and in collaborations with seven world-leading companies in the wind and tidal energy sector. The student will work in close collaborations with two postdocs funded by this grant.
NOTES ON APPLYING
- Please check additional instructions on https://voilab.eng.ed.ac.uk/phd
- Nominate Dr Ignazio Maria Viola as Supervisor when prompted
- Quote the project title as well as 'CDT WAMSS' when asked for your Project Proposal
- The position will remain open untill filled. Applications will be reviewed from 1st February 2021
Minimum entry qualification - an Honours degree at 2:1 or above (or International equivalent) in a relevant science or engineering discipline, possibly supported by an MSc Degree. Further information on English language requirements for EU/Overseas applicants.
See https://voilab.eng.ed.ac.uk/phd for funding details