A Simple Nozzle-Diffuser Duct Used as a Kuroshio Energy Harvester

Yeh, Ping Hung; Tsai, Shang-Yu; Chen, Wei‐Ren; Wu, Shing-Nan; Hsieh, Meng-Chang; Chen, Bang-Fuh

doi:10.3390/pr9091552

Cited by 3 publications

(1 citation statement)

References 9 publications

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“…Additionally, Ref. [20] conducted a feasibility study on a nozzle-diffuser duct as an energy harvester for Kuroshio currents. It employed computational fluid dynamics simulations in ANSYS Fluent to calculate the drag and mass coefficients of the duct anchored to the seabed.…”

Section: Introductionmentioning

confidence: 99%

Velocity Augmentation Model for an Empty Concentrator-Diffuser-Augmented Wind Turbine and Optimisation of Geometrical Parameters Using Surface Response Methodology

Shambira,

Makaka,

Mukumba

2024

Sustainability

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Wind energy, renowned for cost-effectiveness and eco-friendliness, addresses global energy needs amid fossil fuel scarcity and environmental concerns. In low-wind speed regions, optimising wind turbine performance becomes vital and achievable by augmenting wind velocity at the turbine rotor using augmentation systems such as concentrators and diffusers. This study focuses on developing a velocity augmentation model that correctly predicts the throat velocity in an empty concentrator-diffuser-augmented wind turbine (CDaugWT) design and determines optimal geometrical parameters. Utilising response surface methodology (RSM) in Design Expert 13 and computational fluid dynamics (CFD) in ANSYS Fluent, 86 runs were analysed, optimising parameters such as diffuser and concentrator angles and lengths, throat length, and flange height. The ANOVA analysis confirmed the model’s significance (p < 0.05). Notably, the interaction between the concentrator’s length and the diffuser’s length had the highest impact on the throat velocity. The model showed a strong correlation (R2 = 0.9581) and adequate precision (ratio value of 49.655). A low coefficient of variation (C.V.% = 0.1149) highlighted the model’s reliability. The findings revealed a 1.953-fold increase in inlet wind speed at the throat position. Optimal geometrical parameters for the CDaugWT included a diffuser angle of 10°, concentrator angle of 20°, concentrator length of 375 mm (0.62Rth), diffuser length of 975 mm (1.61Rth), throat length of 70 mm (0.12Rth), and flange height of 100 mm (0.17Rth) where Rth is the throat radius. A desirability value of 0.9, close to 1, showed a successful optimisation. CFD simulations and RSM reduced calculation cost and time when determining optimal geometrical parameters for the CDaugWT design.

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Section: Introductionmentioning

confidence: 99%

Velocity Augmentation Model for an Empty Concentrator-Diffuser-Augmented Wind Turbine and Optimisation of Geometrical Parameters Using Surface Response Methodology

Shambira,

Makaka,

Mukumba

2024

Sustainability

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Reliability modelling of ocean current energy conversion systems through both analytical and Monte Carlo methods

Ghaedi

2023

Ocean Engineering

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水中浮遊式海流発電システムの開発と実海域実証試験における応力計測

Dodo,

Okada

2023

J.JASNAOE

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The Kuroshio current flowing near the coastal areas of Japan is one of the strongest ocean currents in the world. In addition, it is expected to be a stable power source of renewable energy from the ocean. Recently various ideas are studied to utilize the Kuroshio current for power generation by researchers worldwide. But there has hardly ever been report on demonstration tests in actual sea areas and stress measurement of the demonstration machine.We are developing a floating-type ocean current turbine system to utilize the Kuroshio current for power generation supported by NEDO. In this paper, we report the result of demonstration tests in the actual sea area. Especially the power curve was obtained from the measurement in the demonstration test and we confirmed that the estimated capacity factor using the power curve fulfills our initial expectation.As a result of the stress measurement, good agreement was observed in general between the measured stresses and the FEM results. However, it was confirmed that with the turbine rotating, the hull may vibrate significantly with the frequencies corresponding to the multiples of the turbine rotation. This is considered to be a resonance of the hull at those frequencies, and although the absolute amplitude of the vibration is small and does not pose a problem for this demonstration test machine, it may become a design issue for future large-scale commercial machines.

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A Simple Nozzle-Diffuser Duct Used as a Kuroshio Energy Harvester

Cited by 3 publications

References 9 publications

Velocity Augmentation Model for an Empty Concentrator-Diffuser-Augmented Wind Turbine and Optimisation of Geometrical Parameters Using Surface Response Methodology

Velocity Augmentation Model for an Empty Concentrator-Diffuser-Augmented Wind Turbine and Optimisation of Geometrical Parameters Using Surface Response Methodology

Reliability modelling of ocean current energy conversion systems through both analytical and Monte Carlo methods

水中浮遊式海流発電システムの開発と実海域実証試験における応力計測

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