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Dr. Matthew Allmark
Cardiff Marine Energy Research Group, School of Engineering, College of Physical Sciences and Engineering, Cardiff University, Cardiff CF24 3AA, UK

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0 Condition Monitoring
0 Wave Energy
0 Marine Energy
0 Offshore Renewable Energy
0 Tidal Energy

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Journal article
Published: 29 May 2021 in Journal of Marine Science and Engineering
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Tidal devices are likely to faced with shear flows and subjected to various wave climates. The paper presents an experimental study of the combined impacts of shear profile and irregular waves on the loading of a 1/20th scale device operating at peak power extraction. The experiments presented were conducted at various depths to facilitate analysis of the effects of the shear flow and wave impact on the device at various positions in the water column. The fluid field was measured at three different upstream positions and at three depths (top, middle and bottom of the rotor) for each experiment; in doing so, data from the device were captured three times. The fluid measurements were of a high quality and were analysed to present the structure flow upstream of the device, which contained velocity and turbulence profiles. The upstream measurement was utilised to understand the development of flow structures in the approach to the device, and the impact of the flow structures measured was confirmed via cross-covariance calculations. The long datasets gathered were used to produce full rotational probability density functions for the blade-root-bending moments for three blades. The spectral characteristics were also considered, and showed that rotor loading quantities are less reactive to smaller scale flow structures.

ACS Style

Matthew Allmark; Rodrigo Martinez; Stephanie Ordonez-Sanchez; Catherine Lloyd; Tim O’Doherty; Grégory Germain; Benoît Gaurier; Cameron Johnstone. A Phenomenological Study of Lab-Scale Tidal Turbine Loading under Combined Irregular Wave and Shear Flow Conditions. Journal of Marine Science and Engineering 2021, 9, 593 .

AMA Style

Matthew Allmark, Rodrigo Martinez, Stephanie Ordonez-Sanchez, Catherine Lloyd, Tim O’Doherty, Grégory Germain, Benoît Gaurier, Cameron Johnstone. A Phenomenological Study of Lab-Scale Tidal Turbine Loading under Combined Irregular Wave and Shear Flow Conditions. Journal of Marine Science and Engineering. 2021; 9 (6):593.

Chicago/Turabian Style

Matthew Allmark; Rodrigo Martinez; Stephanie Ordonez-Sanchez; Catherine Lloyd; Tim O’Doherty; Grégory Germain; Benoît Gaurier; Cameron Johnstone. 2021. "A Phenomenological Study of Lab-Scale Tidal Turbine Loading under Combined Irregular Wave and Shear Flow Conditions." Journal of Marine Science and Engineering 9, no. 6: 593.

Journal article
Published: 15 December 2020 in Renewable Energy
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The paper presents an experimental campaign developed to contribute to the current research considering the operation of Horizontal Axis Tidal Turbines within stochastic flow conditions, namely turbulent and wake induced flows. The campaign was conducted at approximately a 1/20th-scale within a recirculating flume. Experiments were conducted over five differing setups, yielding a baseline low Turbulence Intensity case, two high turbulence cases and two upstream device generated wake cases. The experiments were conducted at a range of differing rotor velocities established, in a novel way, by utilising both fixed speed and fixed braking torque control. The paper presents analysis of flow measurements to statistically quantify the stochastic flow conditions impinging on the model-scale tidal turbine. The power, thrust, torque and blade root bending moment of single blade were recorded and analysed against the flow conditions generated under the five cases. The analysis showed that it may well be possible to exploit the accelerated region around an upstream turbine to capture marginally higher power (6% increase) from downstream turbines. Lastly, it was found that the control scheme adopted has a significant impact on power and load fluctuations observed at differing rotor velocities.

ACS Style

Matthew Allmark; Robert Ellis; Tim Ebdon; Catherine Lloyd; Stephanie Ordonez-Sanchez; Rodrigo Martinez; Allan Mason-Jones; Cameron Johnstone; Tim O’Doherty. A detailed study of tidal turbine power production and dynamic loading under grid generated turbulence and turbine wake operation. Renewable Energy 2020, 169, 1422 -1439.

AMA Style

Matthew Allmark, Robert Ellis, Tim Ebdon, Catherine Lloyd, Stephanie Ordonez-Sanchez, Rodrigo Martinez, Allan Mason-Jones, Cameron Johnstone, Tim O’Doherty. A detailed study of tidal turbine power production and dynamic loading under grid generated turbulence and turbine wake operation. Renewable Energy. 2020; 169 ():1422-1439.

Chicago/Turabian Style

Matthew Allmark; Robert Ellis; Tim Ebdon; Catherine Lloyd; Stephanie Ordonez-Sanchez; Rodrigo Martinez; Allan Mason-Jones; Cameron Johnstone; Tim O’Doherty. 2020. "A detailed study of tidal turbine power production and dynamic loading under grid generated turbulence and turbine wake operation." Renewable Energy 169, no. : 1422-1439.

Journal article
Published: 04 July 2020 in Ocean Engineering
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To understand the influence of complex hydrodynamic loads on tidal turbines, laboratory testing is necessary as a first approach. Previous laboratory work undertaken gave an indication that the use of speed control strategies may disguise the associated loading range that a turbine may be subjected to when this is operated with a variable speed control strategy. However, the preceding work was undertaken in a highly controlled environment without the influence of turbulent flows. The focus of this paper is directed towards the study of wave-induced loads on tidal turbines when these are controlled using two strategies and the impact that these parameters have on the turbine’s performance when this is operated in a recirculating flume. Laboratory tests were undertaken with a 0.9 m diameter horizontal axis tidal turbine subjected to combined wave and current conditions with both regular and irregular waves. Constant speed and constant torque control strategies have been considered, for which rotor thrust, torque and blade root bending moment have been measured. Results show that similar to previous studies, average loads and power capture values remain unchanged between control strategies and the superposition of waves to the current. However, signal fluctuations are 2 to 3 times higher for torque control than for constant speed control strategy. A phase difference between the periodic signals of the turbine thrust and the incoming waves was also identified, in this case, the phase variation was lower when using torque than speed control. This work thus demonstrates the implication of studying strategies to control a marine converter from early stages of development.

ACS Style

Rodrigo Martinez; Stephanie Ordonez-Sanchez; Matthew Allmark; Catherine Lloyd; Tim O’Doherty; Gregory Germain; Benoit Gaurier; Cameron Johnstone. Analysis of the effects of control strategies and wave climates on the loading and performance of a laboratory scale horizontal axis tidal turbine. Ocean Engineering 2020, 212, 107713 .

AMA Style

Rodrigo Martinez, Stephanie Ordonez-Sanchez, Matthew Allmark, Catherine Lloyd, Tim O’Doherty, Gregory Germain, Benoit Gaurier, Cameron Johnstone. Analysis of the effects of control strategies and wave climates on the loading and performance of a laboratory scale horizontal axis tidal turbine. Ocean Engineering. 2020; 212 ():107713.

Chicago/Turabian Style

Rodrigo Martinez; Stephanie Ordonez-Sanchez; Matthew Allmark; Catherine Lloyd; Tim O’Doherty; Gregory Germain; Benoit Gaurier; Cameron Johnstone. 2020. "Analysis of the effects of control strategies and wave climates on the loading and performance of a laboratory scale horizontal axis tidal turbine." Ocean Engineering 212, no. : 107713.

Journal article
Published: 26 April 2020 in Renewable Energy
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The paper describes the development and characterisation of three 0.9 m diameter lab-scale Horizontal Axis Tidal Turbines. The blade development process has been outlined and was used to generate a design specification. Each turbine houses instrumentation to measure rotor thrust, torque and blade root bending moments on each blade, in both ‘flapwise’ and ‘edgewise’ directions. A permanent magnet synchronous machine and encoder are integrated to allow for servo-control of the turbine as well as to provide position and rotational velocity measurements, resulting in three turbines that can be individually controlled using speed or torque control. Analogue signals are captured via a real-time operating system and field programmable gate array hardware architecture facilitating sample rates of up to 2 kHz. Results from testing the pilot turbine at three differing facilities during the development process are presented. Here good agreement, less than 7% variation, was found when comparing the testing undertaken at various flume and tow tank facilities. Lastly, the findings of a test campaign to characterise the performance of each of the three turbines are presented. Very good agreement in non-dimensional values for each of the three manufactured turbines was found.

ACS Style

Matthew Allmark; Robert Ellis; Catherine Lloyd; Stephanie Ordonez-Sanchez; Kate Johannesen; Carl Byrne; Cameron Johnstone; Tim O’Doherty; Allan Mason-Jones. The development, design and characterisation of a scale model Horizontal Axis Tidal Turbine for dynamic load quantification. Renewable Energy 2020, 156, 913 -930.

AMA Style

Matthew Allmark, Robert Ellis, Catherine Lloyd, Stephanie Ordonez-Sanchez, Kate Johannesen, Carl Byrne, Cameron Johnstone, Tim O’Doherty, Allan Mason-Jones. The development, design and characterisation of a scale model Horizontal Axis Tidal Turbine for dynamic load quantification. Renewable Energy. 2020; 156 ():913-930.

Chicago/Turabian Style

Matthew Allmark; Robert Ellis; Catherine Lloyd; Stephanie Ordonez-Sanchez; Kate Johannesen; Carl Byrne; Cameron Johnstone; Tim O’Doherty; Allan Mason-Jones. 2020. "The development, design and characterisation of a scale model Horizontal Axis Tidal Turbine for dynamic load quantification." Renewable Energy 156, no. : 913-930.

Journal article
Published: 30 December 2019 in Journal of Fluids and Structures
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The tidal energy industry is progressing rapidly, but there are still barriers to overcome to realise the commercial potential of this sector. Large magnitude and highly variable loads caused by waves acting on the turbine are of particular concern. Composite blades with in-built bend-twist elastic response may reduce these peak loads, by passively feathering with increasing thrust. This could decrease capital costs by lowering the design loads, and improve robustness through the mitigation of pitch mechanisms. In this study, the previous research is extended to examine the performance of bend-twist blades in combined wave–current flow, which will frequently be encountered in the field. A scaled 3 bladed turbine was tested in the flume at IFREMER with bend-twist composite blades and equivalent rigid blades, sequentially under current and co-directional wave–current cases. In agreement with previous research, when the turbine was operating in current alone at higher tip speed ratios the bend-twist blades reduced the mean thrust and power compared to the rigid blades. Under the specific wave–current condition tested the average loads were similar on both blade sets. Nevertheless, the bend-twist blades substantially reduced the magnitudes of the average thrust and torque fluctuations per wave cycle, by up to 10% and 14% respectively.

ACS Style

Kate E. Porter; Stephanie E. Ordonez-Sanchez; Robynne E. Murray; Matthew Allmark; Cameron M. Johnstone; Tim O’Doherty; Allan Mason-Jones; Darrel A. Doman; Michael J. Pegg. Flume testing of passively adaptive composite tidal turbine blades under combined wave and current loading. Journal of Fluids and Structures 2019, 93, 102825 .

AMA Style

Kate E. Porter, Stephanie E. Ordonez-Sanchez, Robynne E. Murray, Matthew Allmark, Cameron M. Johnstone, Tim O’Doherty, Allan Mason-Jones, Darrel A. Doman, Michael J. Pegg. Flume testing of passively adaptive composite tidal turbine blades under combined wave and current loading. Journal of Fluids and Structures. 2019; 93 ():102825.

Chicago/Turabian Style

Kate E. Porter; Stephanie E. Ordonez-Sanchez; Robynne E. Murray; Matthew Allmark; Cameron M. Johnstone; Tim O’Doherty; Allan Mason-Jones; Darrel A. Doman; Michael J. Pegg. 2019. "Flume testing of passively adaptive composite tidal turbine blades under combined wave and current loading." Journal of Fluids and Structures 93, no. : 102825.

Journal article
Published: 01 July 2019 in Energy
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Temporal variability in renewable energy presents a major challenge for electrical grid systems. Tides are considered predictable due to their regular periodicity; however, the persistence and quality of tidal-stream generated electricity is unknown. This paper is the first study that attempts to address this knowledge gap through direct measurements of rotor-shaft power and shore-side voltage from a 1 MW, rated at grid-connection, tidal turbine (Orkney Islands, UK). Tidal asymmetry in turbulence parameters, flow speed and power variability were observed. Variability in the power at 0.5 Hz, associated with the 10-min running mean, was low (standard deviation 10–12% of rated power), with lower variability associated with higher flow speed and reduced turbulence intensity. Variability of shore-side measured voltage was well within acceptable levels (∼0.3% at 0.5 Hz). Variability in turbine power had <1% difference in energy yield calculation, even with a skewed power variability distribution. Finally, using a “t-location” distribution of observed fine-scale power variability, in combination with an idealised power curve, a synthetic power variability model reliably downscaled 30 min tidal velocity simulations to power at 0.5 Hz (R2 = 85% and ∼14% error). Therefore, the predictability and quality of tidal-stream energy may be undervalued in a future, high-penetration renewable energy, electricity grid.

ACS Style

Matt Lewis; James McNaughton; Concha Márquez-Dominguez; Grazia Todeschini; Michael Togneri; Ian Masters; Matthew Allmark; Tim Stallard; Simon Neill; Alice Goward Brown; Peter Robins. Power variability of tidal-stream energy and implications for electricity supply. Energy 2019, 183, 1061 -1074.

AMA Style

Matt Lewis, James McNaughton, Concha Márquez-Dominguez, Grazia Todeschini, Michael Togneri, Ian Masters, Matthew Allmark, Tim Stallard, Simon Neill, Alice Goward Brown, Peter Robins. Power variability of tidal-stream energy and implications for electricity supply. Energy. 2019; 183 ():1061-1074.

Chicago/Turabian Style

Matt Lewis; James McNaughton; Concha Márquez-Dominguez; Grazia Todeschini; Michael Togneri; Ian Masters; Matthew Allmark; Tim Stallard; Simon Neill; Alice Goward Brown; Peter Robins. 2019. "Power variability of tidal-stream energy and implications for electricity supply." Energy 183, no. : 1061-1074.

Journal article
Published: 15 May 2019 in Journal of Marine Science and Engineering
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Marine renewables represent a promising and innovative alternative source for satisfying the energy demands of growing populations while reducing the consumption of fossil fuels. Most technological advancements and energy yield assessments have focused on promoting the use of kinetic energy from tidal streams with flow velocities higher than 2.0 m s−1. However, slower-moving flows from ocean currents are recently explored due to their nearly continuous and unidirectional seasonal flows. In this study, the potential of the Yucatan Current was analysed at nearshore sites over the insular shelf of Cozumel Island in the Mexican Caribbean. Field measurements were undertaken using a vessel-mounted Acoustic Doppler Current Profiler (ADCP) to analyse the spatial distribution of flow velocities, along with Conductivity-temperature-depth (CTD) profiles as well as data gathering of bathymetry and water elevations. Northward directed flow velocities were identified, with increasing velocities just before the end of the strait of the Cozumel Channel, where average velocities in the region of 0.88–1.04 m s−1 were recorded. An estimation of power delivery using horizontal axis turbines was undertaken with Blade Element Momentum theory. It was estimated that nearly 3.2 MW could be supplied to Cozumel Island, amounting to about 10% of its electricity consumption.

ACS Style

Juan Carlos Alcérreca-Huerta; Job Immanuel Encarnacion; Stephanie Ordoñez-Sánchez; Mariana Callejas-Jiménez; Gabriel Gallegos Diez Barroso; Matthew Allmark; Ismael Mariño-Tapia; Rodolfo Silva Casarín; Tim O’Doherty; Cameron Johnstone; Laura Carrillo. Energy Yield Assessment from Ocean Currents in the Insular Shelf of Cozumel Island. Journal of Marine Science and Engineering 2019, 7, 147 .

AMA Style

Juan Carlos Alcérreca-Huerta, Job Immanuel Encarnacion, Stephanie Ordoñez-Sánchez, Mariana Callejas-Jiménez, Gabriel Gallegos Diez Barroso, Matthew Allmark, Ismael Mariño-Tapia, Rodolfo Silva Casarín, Tim O’Doherty, Cameron Johnstone, Laura Carrillo. Energy Yield Assessment from Ocean Currents in the Insular Shelf of Cozumel Island. Journal of Marine Science and Engineering. 2019; 7 (5):147.

Chicago/Turabian Style

Juan Carlos Alcérreca-Huerta; Job Immanuel Encarnacion; Stephanie Ordoñez-Sánchez; Mariana Callejas-Jiménez; Gabriel Gallegos Diez Barroso; Matthew Allmark; Ismael Mariño-Tapia; Rodolfo Silva Casarín; Tim O’Doherty; Cameron Johnstone; Laura Carrillo. 2019. "Energy Yield Assessment from Ocean Currents in the Insular Shelf of Cozumel Island." Journal of Marine Science and Engineering 7, no. 5: 147.

Journal article
Published: 16 April 2019 in Ocean Engineering
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As previously experienced by the wind industry, it is envisaged that tidal stream turbine blades will present misalignments or blade deformations over time as they are constantly working under harsh and highly unsteady environments. Blade misalignment will affect the power capture of a tidal stream turbine and if not detected in time could affect other components of the drive train. Therefore, the aim of this paper is to compare the use of two numerical modelling techniques to predict the performance of a tidal stream turbine working under off-design conditions, in this case, the misalignment of one or more blades. The techniques used in this study are Blade Element Momentum Theory and Computational Fluid Dynamics. The numerical models simulate the performance of a three-bladed horizontal axis tidal stream turbine with one or two blades offset from the optimum pitch setting. The simulations were undertaken at 1.0 m/s flow speeds. The results demonstrated that both unsteady BEMT and steady or transient CFD are able to predict power coefficients when there is a certain level of misalignment in one or even two blades. However, both techniques failed to accurately predict a loss of power performance at high rotational speeds.

ACS Style

S. Ordonez-Sanchez; R. Ellis; K.E. Porter; Matthew Allmark; T. O'doherty; A. Mason-Jones; C. Johnstone. Numerical models to predict the performance of tidal stream turbines working under off-design conditions. Ocean Engineering 2019, 181, 198 -211.

AMA Style

S. Ordonez-Sanchez, R. Ellis, K.E. Porter, Matthew Allmark, T. O'doherty, A. Mason-Jones, C. Johnstone. Numerical models to predict the performance of tidal stream turbines working under off-design conditions. Ocean Engineering. 2019; 181 ():198-211.

Chicago/Turabian Style

S. Ordonez-Sanchez; R. Ellis; K.E. Porter; Matthew Allmark; T. O'doherty; A. Mason-Jones; C. Johnstone. 2019. "Numerical models to predict the performance of tidal stream turbines working under off-design conditions." Ocean Engineering 181, no. : 198-211.

Journal article
Published: 24 January 2019 in Energies
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The flow developed on a tidal site can be characterized by combinations of turbulence, shear flows, and waves. Horizontal-axis tidal turbines are therefore subjected to dynamic loadings that may compromise the working life of the rotor and drive train components. To this end, a series of experiments were carried out using a 0.9 m horizontal-axis tidal turbine in a tow tank facility. The experiments included two types of regular waveforms, one of them simulating an extreme wave case, the other simulating a more moderate wave case. The second regular wave was designed to match the peak period and significant wave height of an irregular wave which was also tested. Measurements of torque, thrust, and blade-bending moments were taken during the testing campaign. Speed and torque control strategies were implemented for a range of operational points to investigate the influence that a control mode had in the performance of a tidal stream turbine. The results showed similar average power and thrust values were not affected by the control strategy, nor the influence of either the regular or irregular wave cases. However, it was observed that using torque control resulted in an increase of thrust and blade root bending moment fluctuations per wave period. The increase in fluctuations was in the order of 40% when compared to the speed control cases.

ACS Style

Stephanie Ordonez-Sanchez; Matthew Allmark; Kate Porter; Robert Ellis; Catherine Lloyd; Ivan Santic; Tim O’Doherty; Cameron Johnstone. Analysis of a Horizontal-Axis Tidal Turbine Performance in the Presence of Regular and Irregular Waves Using Two Control Strategies. Energies 2019, 12, 367 .

AMA Style

Stephanie Ordonez-Sanchez, Matthew Allmark, Kate Porter, Robert Ellis, Catherine Lloyd, Ivan Santic, Tim O’Doherty, Cameron Johnstone. Analysis of a Horizontal-Axis Tidal Turbine Performance in the Presence of Regular and Irregular Waves Using Two Control Strategies. Energies. 2019; 12 (3):367.

Chicago/Turabian Style

Stephanie Ordonez-Sanchez; Matthew Allmark; Kate Porter; Robert Ellis; Catherine Lloyd; Ivan Santic; Tim O’Doherty; Cameron Johnstone. 2019. "Analysis of a Horizontal-Axis Tidal Turbine Performance in the Presence of Regular and Irregular Waves Using Two Control Strategies." Energies 12, no. 3: 367.

Journal article
Published: 01 July 2018 in Renewable Energy
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ACS Style

Matthew Allmark; Roger Grosvenor; Paul Prickett. Corrigendum to “An approach to the characterisation of the performance of a tidal stream turbine” [Renewable Energy 111 (October 2017) 849–860]. Renewable Energy 2018, 122, 264 .

AMA Style

Matthew Allmark, Roger Grosvenor, Paul Prickett. Corrigendum to “An approach to the characterisation of the performance of a tidal stream turbine” [Renewable Energy 111 (October 2017) 849–860]. Renewable Energy. 2018; 122 ():264.

Chicago/Turabian Style

Matthew Allmark; Roger Grosvenor; Paul Prickett. 2018. "Corrigendum to “An approach to the characterisation of the performance of a tidal stream turbine” [Renewable Energy 111 (October 2017) 849–860]." Renewable Energy 122, no. : 264.

Journal article
Published: 01 June 2018 in International Journal of Prognostics and Health Management
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The sustainable deployment of Horizontal Axis Tidal Turbines will require effective management and maintenance functions. In part, these can be supported by the engineering of suitable condition monitoring systems. The development of such a system is inevitably challenging, particularly given the present limited level of operational data associated with installed turbines during fault onset. To mitigate this limitation, a computational fluid dynamics model is used to simulate the operational response of a turbine under a known set of fault conditions. Turbine rotor imbalance faults were simulated by the introduction of increasing levels of pitch angle offset for a single turbine blade. The effects of these fault cases upon cyclic variations in the torque developed by the turbine rotor were then used to aid creation of a condition monitoring approach. A parametric tidal turbine rotor model was developed based on the outputs of the computational fluid dynamics models. The model was used to facilitate testing of the condition monitoring approach under a variety of more realistic conditions. The condition monitoring approach showed good performance in fault detection and diagnosis for simulations relating to turbulence intensities of up to 2 %. Finally, the condition monitoring approach was applied to simulations of 10 % turbulence intensity. Under the 10 % turbulence intensity case the rotor monitoring approach was successfully demonstrated in its use for fault detection. The paper closes with discussion of the effectiveness of using computational fluid dynamics simulations extended by parametric models to develop condition monitoring systems for horizontal axis tidal turbine applications.

ACS Style

Matthew Allmark; Paul Prickett; Roger Grosvenor; Carwyn Frost. The specification and testing of a Horizontal Axis Tidal Turbine Rotor Monitoring approach. International Journal of Prognostics and Health Management 2018, 9, 1 .

AMA Style

Matthew Allmark, Paul Prickett, Roger Grosvenor, Carwyn Frost. The specification and testing of a Horizontal Axis Tidal Turbine Rotor Monitoring approach. International Journal of Prognostics and Health Management. 2018; 9 (2):1.

Chicago/Turabian Style

Matthew Allmark; Paul Prickett; Roger Grosvenor; Carwyn Frost. 2018. "The specification and testing of a Horizontal Axis Tidal Turbine Rotor Monitoring approach." International Journal of Prognostics and Health Management 9, no. 2: 1.

Journal article
Published: 01 October 2017 in Renewable Energy
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ACS Style

Matthew Allmark; Roger Grosvenor; Paul Prickett. An approach to the characterisation of the performance of a tidal stream turbine. Renewable Energy 2017, 111, 849 -860.

AMA Style

Matthew Allmark, Roger Grosvenor, Paul Prickett. An approach to the characterisation of the performance of a tidal stream turbine. Renewable Energy. 2017; 111 ():849-860.

Chicago/Turabian Style

Matthew Allmark; Roger Grosvenor; Paul Prickett. 2017. "An approach to the characterisation of the performance of a tidal stream turbine." Renewable Energy 111, no. : 849-860.

Journal article
Published: 01 September 2016 in International Journal of Marine Energy
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This study used computational fluid dynamics to investigate the effect of waves and a velocity profile on the performance of a tidal stream turbine (TST). A full scale TST was transiently modelled operating near its maximum power point, and then subjected to waves both in and out of phase with its period of rotation. A profile was then added to one of the wave models. For this set of conditions it was found that the longer period and in-phase wave had a significant effect on the power range fluctuations, with more modest variations for thrust and the average values, although this is dependent on the turbine tip speed ratio. The addition of the profile had a strong effect on the bending moment. It has been concluded that a naturally varying sea state may yield a smoothing effect in this turbine response, but that with further structural investigation it may be that some measuring and mitigation techniques are required in the event of a predominantly single long period, in-phase wave.

ACS Style

Sarah Tatum; Matthew Allmark; Carwyn Frost; Daphne O’Doherty; Allan Mason-Jones; Tim O'Doherty. CFD modelling of a tidal stream turbine subjected to profiled flow and surface gravity waves. International Journal of Marine Energy 2016, 15, 156 -174.

AMA Style

Sarah Tatum, Matthew Allmark, Carwyn Frost, Daphne O’Doherty, Allan Mason-Jones, Tim O'Doherty. CFD modelling of a tidal stream turbine subjected to profiled flow and surface gravity waves. International Journal of Marine Energy. 2016; 15 ():156-174.

Chicago/Turabian Style

Sarah Tatum; Matthew Allmark; Carwyn Frost; Daphne O’Doherty; Allan Mason-Jones; Tim O'Doherty. 2016. "CFD modelling of a tidal stream turbine subjected to profiled flow and surface gravity waves." International Journal of Marine Energy 15, no. : 156-174.

Journal article
Published: 01 June 2016 in International Journal of Marine Energy
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The transient interaction between tidal currents and the rotation of a horizontal axis turbine rotor have the potential to induce high asymmetric loadings, which are subsequently transmitted to the drive shaft and potentially high speed drive train components. To mitigate the potential for early component failure, analysis of asymmetric loading on marine turbines is fundamental to the design process. To investigate these loads a turbine mounted on a circular stanchion has been used to highlight the effects of introducing more realistic boundary conditions. Depending on their wavelength, waves can also have a significant effect on the overall design decisions and placement of devices. Thrust loading and bending moments applied to the drive shaft can be of the order of hundreds of kN and kNm respectively.Knowledge of the flow regime can allow designers to evaluate material selection for components and incorporate some deformation capability of the turbine blades to increase the power output and potentially alleviate some of the stress distribution through key structural points. The resulting data can then be used to estimate component life via fatigue prediction.This paper includes a multi-physics approach to modelling tidal energy devices and the potential for modelling to inform device condition monitoring

ACS Style

S.C. Tatum; C.H. Frost; Matthew Allmark; D.M. O’Doherty; A. Mason-Jones; Paul Prickett; R.I. Grosvenor; C.B. Byrne; Tim O'Doherty. Wave–current interaction effects on tidal stream turbine performance and loading characteristics. International Journal of Marine Energy 2016, 14, 161 -179.

AMA Style

S.C. Tatum, C.H. Frost, Matthew Allmark, D.M. O’Doherty, A. Mason-Jones, Paul Prickett, R.I. Grosvenor, C.B. Byrne, Tim O'Doherty. Wave–current interaction effects on tidal stream turbine performance and loading characteristics. International Journal of Marine Energy. 2016; 14 ():161-179.

Chicago/Turabian Style

S.C. Tatum; C.H. Frost; Matthew Allmark; D.M. O’Doherty; A. Mason-Jones; Paul Prickett; R.I. Grosvenor; C.B. Byrne; Tim O'Doherty. 2016. "Wave–current interaction effects on tidal stream turbine performance and loading characteristics." International Journal of Marine Energy 14, no. : 161-179.