Dynamics of floating water-wave energy extraction devices
Lead Research Organisation:
University of Surrey
Department Name: Mathematics
Abstract
The ocean is, essentially, a perpetual motion machine with vast reservoirs of energy, some of which is delivered to the shoreline in the form of waves. The extraction of this energy is one of the great under-utilized branches of renewable energy, and the UK is well placed to exploit this energy: the UK shoreline attracts about 35% of the total wave energy available to ALL of Europe.
Although various wave energy converters (WECs) for the extraction of energy from ocean waves have been around
for a long time, it is only recently that both government and industry have developed a strong and ambitious interest,
and the number of potential WECs for extraction of energy from the ocean wave environment is growing. The interest in this proposal is the OWEL WEC. It is a floating rectangular device open at one end to allow waves in. It is a moored deep-water offshore structure interacting with ocean waves. The wave energy is extracted via a power take-off system. It is one of the most difficult WECs to model.
The interest in this proposal is to tackle three main mathematical modelling issues: (1) the dynamics of the waves once they are trapped inside the vessel, (2) the effect of resonance between components, and (3) the dynamic feedback due to multi-fold coupling between interior waves, the ambient ocean wave field, vessel dynamics and mooring dynamics. The ultimate goal is to build up a model which, starting with an ambient ocean wave field, describes the detailed process whereby this energy is extracted and delivered to the power take off system.
Although various wave energy converters (WECs) for the extraction of energy from ocean waves have been around
for a long time, it is only recently that both government and industry have developed a strong and ambitious interest,
and the number of potential WECs for extraction of energy from the ocean wave environment is growing. The interest in this proposal is the OWEL WEC. It is a floating rectangular device open at one end to allow waves in. It is a moored deep-water offshore structure interacting with ocean waves. The wave energy is extracted via a power take-off system. It is one of the most difficult WECs to model.
The interest in this proposal is to tackle three main mathematical modelling issues: (1) the dynamics of the waves once they are trapped inside the vessel, (2) the effect of resonance between components, and (3) the dynamic feedback due to multi-fold coupling between interior waves, the ambient ocean wave field, vessel dynamics and mooring dynamics. The ultimate goal is to build up a model which, starting with an ambient ocean wave field, describes the detailed process whereby this energy is extracted and delivered to the power take off system.
Planned Impact
The mathematical modelling of the OWEL configuration is one of the most difficult of the WECs to model. It requires a novel combination of fluid mechanics, geometric mechanics, numerical analysis, modelling and applied mathematics. The principal impact will be on the design and implementation of the current succession of WECs by OWEL. This proposed project
will be getting in on the ground floor since the first prototype is scheduled for deployment in 2013 and long term plans include a succession of improved models over the next 20 years. This impact will be facilitated by regular communication, punctuated by quarterly meetings at the Bristol office or at Surrey.
The principal features of the OWEL model are generic: interior fluid motion in a floating body, dynamics of floating bodies in waves, and resonances due to multi-fold coupling are all features of a range of marine systems. Hence the mathematical models, analytical tools, and numerical methods will have independent interest.
The practical aspects of impact through dissemination will involve a website, publications, attendance at conferences, and the Surrey Themed Semesters in Spring 2013 and Spring 2015.
There will be a range of impact on the postdoctoral researcher as well. The project offers the opportunity to dig deeply into both fundamental topics, as well as applied and application-oriented topics. The development of expertise in modelling and analysis of the OWEL configuration would position the PDRA to develop into a leading contributor to the mathematical modelling of wave energy extractors, and a person trained in this direction will be extremely important in the long term national strategy for wave energy
extraction in the UK.
will be getting in on the ground floor since the first prototype is scheduled for deployment in 2013 and long term plans include a succession of improved models over the next 20 years. This impact will be facilitated by regular communication, punctuated by quarterly meetings at the Bristol office or at Surrey.
The principal features of the OWEL model are generic: interior fluid motion in a floating body, dynamics of floating bodies in waves, and resonances due to multi-fold coupling are all features of a range of marine systems. Hence the mathematical models, analytical tools, and numerical methods will have independent interest.
The practical aspects of impact through dissemination will involve a website, publications, attendance at conferences, and the Surrey Themed Semesters in Spring 2013 and Spring 2015.
There will be a range of impact on the postdoctoral researcher as well. The project offers the opportunity to dig deeply into both fundamental topics, as well as applied and application-oriented topics. The development of expertise in modelling and analysis of the OWEL configuration would position the PDRA to develop into a leading contributor to the mathematical modelling of wave energy extractors, and a person trained in this direction will be extremely important in the long term national strategy for wave energy
extraction in the UK.
Publications
Alemi Ardakani H
(2015)
Dynamic coupling between horizontal vessel motion and two-layer shallow-water sloshing
in Journal of Fluids and Structures
Alemi Ardakani H
(2016)
Adaptation of f-wave finite volume methods to the two-layer shallow-water equations in a moving vessel with a rigid-lid
in Journal of Computational and Applied Mathematics
Alemi Ardakani H
(2016)
A symplectic integrator for dynamic coupling between nonlinear vessel motion with variable cross-section and bottom topography and interior shallow-water sloshing
in Journal of Fluids and Structures
Alemi Ardakani H
(2016)
Shallow-water sloshing in a moving vessel with variable cross-section and wetting-drying using an extension of George's well-balanced finite volume solver
in Journal of Computational Physics
Alemi Ardakani H
(2016)
Adaptation of f-wave finite volume methods to the Boonkasame-Milewski non-Boussinesq two-layer shallow interfacial sloshing equations coupled to the vessel motion
in European Journal of Mechanics - B/Fluids
Ardakani H
(2016)
Numerical simulations of dynamic coupling between shallow-water sloshing and horizontal vessel motion with baffles
in Fluid Dynamics Research
Ardakani HA
(2019)
A variational principle for fluid sloshing with vorticity, dynamically coupled to vessel motion.
in Proceedings. Mathematical, physical, and engineering sciences
Bajpai A
(2015)
Planetary Monocular Simultaneous Localization and Mapping
in Journal of Field Robotics
Bridges
(2017)
Symmetry, Phase Modulation and Nonlinear Waves
Bridges T
(2016)
UK Success Stories in Industrial Mathematics
| Description | We have discovered a simplified mathematical model for the OWEL ocean wave energy convertor. This model is useful for parametric studies to determine the optimal shape and performance of the OWEL device. We have validated the model, and performed extensive analysis and numerics on it, which are reported in the publications listed above. Since the project finished, we discovered a new variational principle for dynamic coupling between vessel motion and fluid flow with vorticity. It has been published in the Proceedings A of the Royal Society of London. |
| Exploitation Route | Can be used in the next generation patent application. |
| Sectors | Aerospace Defence and Marine |
| URL | http://personal.maths.surrey.ac.uk/st/T.Bridges/OWEL/ |
| Description | The findings have been used by the company Offshore Wave Energy Ltd to help in the design of the next generation OWEL ocean wave energy convertor. |
| First Year Of Impact | 2015 |
| Sector | Aerospace, Defence and Marine |
| Impact Types | Economic |
| Description | ONRG Conference Grants |
| Amount | $18,000 (USD) |
| Funding ID | N62909-14-1-C157 |
| Organisation | US Navy |
| Department | US Office of Naval Research Global |
| Sector | Academic/University |
| Country | United States |
| Start | 03/2014 |
| End | 03/2015 |
| Description | LWEC Maths Forsees |
| Organisation | University of Leeds |
| Country | United Kingdom |
| Sector | Academic/University |
| PI Contribution | The collaboration starts in March 2015. It is an EPSRC funded Network led by Prof Onno Bokhove at the University of Leeds. The theme is "multi-scale mathematics for mitigating severe environmental events". The objectives are 1. To forge collaborations between the mathematical sciences and environmental change communities by coupling and mathematically analysing the various model components identified, i.e., precipitation and storm forecasts with river and coastal flood models as well as coastal erosion models, and wind and flood forecasts with urban pollutant dispersal models. 2. To facilitate an active exchange of knowledge between the academic mathematical and environmental science communities and environmental stakeholders. 3. To rethink the approach to extreme events analysis in the severe weather events proposed, and to quantify the uncertainty inherent in hazard predictions. 4. To promote mathematical modelling of environmental hazards in the wider UK community (in research, particularly among students and early career researchers, industry, society) and impact on the environmental hazards sector (e.g. through an increase of the number and quality of UK experts). 5. To create awareness among the general public of the mathematical and engineering challenges involved in living with environmental change and severe weather hazards, and highlight the key role of mathematics through communication and outreach projects. |
| Collaborator Contribution | The partnership is new, with the grant starting in March 2015. |
| Impact | Multi-disciplinary: mathematics and and all branches of environmental science |
| Start Year | 2014 |
| Description | Ocean Wave Energy |
| Organisation | Offshore Wave Energy Limited |
| Country | United Kingdom |
| Sector | Private |
| PI Contribution | We interact on a regular basis with this industrial firm. We are modelling a device that they are developing for commercial wave energy harvesting. |
| Collaborator Contribution | New simplified models for ocean wave energy harvesters. |
| Impact | Multi-disciplinary - mathematics, naval architecture, and oceanography |
| Start Year | 2012 |
| Description | Water Waves in Industry Day |
| Organisation | University of Cambridge |
| Department | Turing Gateway to Mathematics |
| Country | United Kingdom |
| Sector | Academic/University |
| PI Contribution | Co-organised a one-day meeting on water waves in industry with an emphasis on ocean wave energy harvesting. |
| Collaborator Contribution | The Turing Gateway managed all aspects of the one-day meeting. |
| Impact | Multi-disciplinary: the one-day meeting brought together mathematicians working on the theory of water waves with representatives from industry. |
| Start Year | 2014 |
| Description | Research Seminar at University of East Anglia by Matthew Turner |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | Regional |
| Primary Audience | Other audiences |
| Results and Impact | Giving a Research seminar to University academics in the Mathematics Department on an element of the research for this project. |
| Year(s) Of Engagement Activity | 2017 |
| Description | Seminar at UEA by TJB |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | Regional |
| Primary Audience | Postgraduate students |
| Results and Impact | Seminar to the mathematics department at the University of East Anglia |
| Year(s) Of Engagement Activity | 2017 |
| Description | Talks by Research Fellow |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Other audiences |
| Results and Impact | Talk at the SIAM conference on Nonlinear Waves, Cambridge UK, 2014. Talk at the Geometric Mechanics workshop at Surrey in 2014. Talk at BAMC 2015 in Cambridge, UK. Talk at the Surrey Mathematics Research Day in 2015. |
| Year(s) Of Engagement Activity | 2014,2015 |
| Description | Talks by co-investigator |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | Regional |
| Primary Audience | Other audiences |
| Results and Impact | Talk at the `2nd Applied Geometric Mechanics Meeting on Geometric Fluid Dynamics' held at Surrey in January 2016. |
| Year(s) Of Engagement Activity | 2016 |