Flexible multibody dynamics modelling of point-absorber wave energy converters

Lin Wang, Athanasios Kolios, Lin Cui, Qihu Sheng

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

As an inexhaustible and environmentally-friendly energy resource, ocean wave power, which is extracted from ocean waves through WECs (wave energy converters), is highly valued by coastal countries. Compared to other types of WECs, point-absorber WECs, the main body of which can be fixed on a platform (e.g. ship), save on installation costs and therefore have concentrated significant interest among researchers and technology developers. In the development of point-absorber WECs, it is crucial to develop a reliable structural model to accurately predict the structural dynamic responses of WECs subjected to wave loadings. In this work, a FMBD (flexible multibody dynamics) model, which is a combination of MBD (multibody dynamics) and FEA (finite element analysis), has been developed for point-absorber WECs. The FMBD model has been applied to the structural modelling of the NOTC (National Ocean Technology Centre) 10 kW multiple-point-absorber WEC. The floater arm tip displacement and velocity obtained from the FMBD model are validated against the values obtained from an analytical model, which is also developed in this work. The results from the FMBD model show reasonable agreement with those from the analytical model, with a relative difference of 10.1% at the maximum value of the floater arm tip displacement. The FMBD model is further used to calculate the stress distributions, fatigue life, deformations, modal frequencies and modal shapes of the structure. The results indicate that WECs are prone to experience fatigue failure, with the shortest fatigue life (2 years) observed in the floater arm. The FMBD model developed in this work is demonstrated to be capable of accurately modelling point-absorber WECs, providing valuable information for designers to further optimise the structure and assess the reliability of WECs.

LanguageEnglish
Pages790-801
Number of pages12
JournalRenewable Energy
Volume127
Early online date7 May 2018
DOIs
Publication statusPublished - 30 Nov 2018

Fingerprint

Dynamic models
Water waves
Fatigue of materials
Analytical models
Wave power
Structural dynamics
Energy resources
Dynamic response
Stress concentration
Ships
Finite element method
Costs

Keywords

  • finite element analysis (FEA)
  • flexible multibody dynamic (FMBD)
  • multibody dynamics (MBD)
  • NOTC 10 kW multi-point-absorber WEC
  • point-absorber WECs
  • wave energy converters (WECs)

Cite this

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title = "Flexible multibody dynamics modelling of point-absorber wave energy converters",
abstract = "As an inexhaustible and environmentally-friendly energy resource, ocean wave power, which is extracted from ocean waves through WECs (wave energy converters), is highly valued by coastal countries. Compared to other types of WECs, point-absorber WECs, the main body of which can be fixed on a platform (e.g. ship), save on installation costs and therefore have concentrated significant interest among researchers and technology developers. In the development of point-absorber WECs, it is crucial to develop a reliable structural model to accurately predict the structural dynamic responses of WECs subjected to wave loadings. In this work, a FMBD (flexible multibody dynamics) model, which is a combination of MBD (multibody dynamics) and FEA (finite element analysis), has been developed for point-absorber WECs. The FMBD model has been applied to the structural modelling of the NOTC (National Ocean Technology Centre) 10 kW multiple-point-absorber WEC. The floater arm tip displacement and velocity obtained from the FMBD model are validated against the values obtained from an analytical model, which is also developed in this work. The results from the FMBD model show reasonable agreement with those from the analytical model, with a relative difference of 10.1{\%} at the maximum value of the floater arm tip displacement. The FMBD model is further used to calculate the stress distributions, fatigue life, deformations, modal frequencies and modal shapes of the structure. The results indicate that WECs are prone to experience fatigue failure, with the shortest fatigue life (2 years) observed in the floater arm. The FMBD model developed in this work is demonstrated to be capable of accurately modelling point-absorber WECs, providing valuable information for designers to further optimise the structure and assess the reliability of WECs.",
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Flexible multibody dynamics modelling of point-absorber wave energy converters. / Wang, Lin; Kolios, Athanasios; Cui, Lin; Sheng, Qihu.

In: Renewable Energy, Vol. 127, 30.11.2018, p. 790-801.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Flexible multibody dynamics modelling of point-absorber wave energy converters

AU - Wang, Lin

AU - Kolios, Athanasios

AU - Cui, Lin

AU - Sheng, Qihu

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Y1 - 2018/11/30

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AB - As an inexhaustible and environmentally-friendly energy resource, ocean wave power, which is extracted from ocean waves through WECs (wave energy converters), is highly valued by coastal countries. Compared to other types of WECs, point-absorber WECs, the main body of which can be fixed on a platform (e.g. ship), save on installation costs and therefore have concentrated significant interest among researchers and technology developers. In the development of point-absorber WECs, it is crucial to develop a reliable structural model to accurately predict the structural dynamic responses of WECs subjected to wave loadings. In this work, a FMBD (flexible multibody dynamics) model, which is a combination of MBD (multibody dynamics) and FEA (finite element analysis), has been developed for point-absorber WECs. The FMBD model has been applied to the structural modelling of the NOTC (National Ocean Technology Centre) 10 kW multiple-point-absorber WEC. The floater arm tip displacement and velocity obtained from the FMBD model are validated against the values obtained from an analytical model, which is also developed in this work. The results from the FMBD model show reasonable agreement with those from the analytical model, with a relative difference of 10.1% at the maximum value of the floater arm tip displacement. The FMBD model is further used to calculate the stress distributions, fatigue life, deformations, modal frequencies and modal shapes of the structure. The results indicate that WECs are prone to experience fatigue failure, with the shortest fatigue life (2 years) observed in the floater arm. The FMBD model developed in this work is demonstrated to be capable of accurately modelling point-absorber WECs, providing valuable information for designers to further optimise the structure and assess the reliability of WECs.

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KW - multibody dynamics (MBD)

KW - NOTC 10 kW multi-point-absorber WEC

KW - point-absorber WECs

KW - wave energy converters (WECs)

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SP - 790

EP - 801

JO - Renewable Energy

T2 - Renewable Energy

JF - Renewable Energy

SN - 0960-1481

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