The Experts below are selected from a list of 552 Experts worldwide ranked by ideXlab platform

Wim Desmet - One of the best experts on this subject based on the ideXlab platform.

  • Assessment of excitation mechanisms and structural flexibility influence in excitation propagation in multi-megawatt wind turbine gearboxes: Experiments and flexible multibody model optimization
    Mechanical Systems and Signal Processing, 2013
    Co-Authors: Jan Helsen, Ben Marrant, Frederik Vanhollebeke, Filip De Coninck, Dries Berckmans, Dirk Vandepitte, Wim Desmet
    Abstract:

    Reliable gearbox design calculations require sufficient insight in gearbox dynamics, which is determined by the interaction between the different excitation mechanisms and the gearbox modal behavior. Both external gearbox excitation originating from the wind turbine drive train and internal gearbox excitation are important. Moreover with regard to the modal behavior the different gearbox structural components: Planet Carrier, shafts and housing are of influence. The main objective of this article is the experimental investigation of the interaction between the different excitation mechanisms and the gearbox modal behavior. The insights gathered are used to prove the need for accurate gear mesh representation and structural flexibility within the corresponding flexible multibody gearbox simulation model. Experiments are conducted on a dynamic 13.2 MW test facility on which two multi-megawatt wind turbine gearboxes are placed back to back and subjected to a speed run-up. Measurement sensors consist of bearing displacement sensors, torque sensors, encoders and accelerometers distributed over the gearbox. Excitation order amplitudes on different locations in the gearbox are determined by means of a Time Varying Discrete Fourier Transform (TVDFT) order tracking on the measured sensor signals. Moreover the propagation of this excitation throughout the gearbox is assessed. Relating the orders to the corresponding excitation source allows the definition of order influence regions within the gearbox. The interaction between the gear mesh order excitation and structural flexibility is shown. © 2013 Elsevier Ltd.

  • Multibody modelling of varying complexity for modal behaviour analysis of wind turbine gearboxes
    Renewable Energy, 2011
    Co-Authors: Jan Helsen, Ben Marrant, Frederik Vanhollebeke, Dirk Vandepitte, Wim Desmet
    Abstract:

    In the currently booming market of wind turbines, a clear focus is put on the design of reliable and cost-effective subsystems, such as the gearbox. A requirement for reliable gearbox design calculations is sufficient insight in the dynamics of the entire wind turbine drive train. Since traditional wind turbine design codes reduce the drive train to just a few degrees of freedom, considerable research effort is spent in advanced modelling and simulation techniques to gain more insights in the dynamics at hand. This work focusses on the gearbox modal behaviour assessment by means of three more complex modelling techniques of varying complexity: the purely torsional-, rigid six degree of freedom with discrete flexibility and flexible multibody technique. Both simulation and experimental results are discussed. Typical mode categories for traditional wind turbine gearboxes are defined. Moreover the challenge of the definition of an accurate approach to condense finite element models for representing the flexible components in the flexible multibody models is overcome. Furthermore the interaction between the structural modes of the Planet Carrier and Planetary ring flexibility with the overall gearbox modes is investigated, resulting in the definition of two new mode categories: the Planet Carrier modes and Planetary ring modes.

  • The influence of flexibility within multibody modeling of multi-megawatt wind turbine gearboxes
    2008
    Co-Authors: Jan Helsen, Dirk Vandepitte, Gert Heirman, Wim Desmet
    Abstract:

    This work discusses the influence of flexibility within the multibody approach for wind-turbine gearbox modeling and validates them, by means of a generic gearbox calculation consisting of one Planetary gear stage and two helical stages. First the state-of-the-art rigid multibody modeling with discrete flexibility is discussed. Secondly flexible multibody modeling by means of reduced finite element models is discussed. The different structures for coupling the reduced finite element structure to the multibody gearbox model are investigated. The modal behavior of a fully flexible model of the high speed helical gear stage is determined and compared to the rigid model. A detailed estimation of the influence of the flexibility of the different components of the Planetary stage is performed. Finally a flexible Planet Carrier is introduced in the full gearbox model and a comparison with the rigid full gearbox model is made

Torgeir Moan - One of the best experts on this subject based on the ideXlab platform.

  • multi body modelling and analysis of a Planet Carrier in a wind turbine gearbox
    Wind Energy, 2013
    Co-Authors: Yihan Xing, Torgeir Moan
    Abstract:

    There have been some recent efforts to numerically model and analyse the wind turbine gearbox. To date, much of the focus has been on increasing model refinement and demonstrating its added value. This paper takes a step back and examines in detail the modelling and analysis of an important wind turbine gearbox component, the Planet Carrier, in a multi-body setting. The Planet Carrier studied in this work comes from the 750 kW wind turbine gearbox used in the National Renewable Energy Laboratory's Gearbox Reliability Collaborative project. The study is performed in two parts. First, the influence of subcomponents mated to the Planet Carrier in the gearbox assembly is investigated in detail. These components consist of the Planet pins, bearings and the main shaft. In the second part of the study, the flexible body modelling of the Planet Carrier for use in multi-body simulations is examined through the use of condensed finite element and multi-body simulation models. Both eigenvalue analyses and time domain simulations are performed. Comparisons are made regarding the eigenfrequencies, categorized mode shapes and the maximum and minimum Planet Carrier rim deflections from the time domain simulations. The mode shapes are categorized into seven distinct deformation patterns. An actual load case from the dynamometer tests, a 100% rated torque loading, is used in the time domain simulations. The results from this comprehensive study provide an insight into the proper modelling of a wind turbine Planet Carrier in a multi-body setting. Copyright © 2012 John Wiley & Sons, Ltd.

  • Multi‐body modelling and analysis of a Planet Carrier in a wind turbine gearbox
    Wind Energy, 2012
    Co-Authors: Yihan Xing, Torgeir Moan
    Abstract:

    There have been some recent efforts to numerically model and analyse the wind turbine gearbox. To date, much of the focus has been on increasing model refinement and demonstrating its added value. This paper takes a step back and examines in detail the modelling and analysis of an important wind turbine gearbox component, the Planet Carrier, in a multi-body setting. The Planet Carrier studied in this work comes from the 750 kW wind turbine gearbox used in the National Renewable Energy Laboratory's Gearbox Reliability Collaborative project. The study is performed in two parts. First, the influence of subcomponents mated to the Planet Carrier in the gearbox assembly is investigated in detail. These components consist of the Planet pins, bearings and the main shaft. In the second part of the study, the flexible body modelling of the Planet Carrier for use in multi-body simulations is examined through the use of condensed finite element and multi-body simulation models. Both eigenvalue analyses and time domain simulations are performed. Comparisons are made regarding the eigenfrequencies, categorized mode shapes and the maximum and minimum Planet Carrier rim deflections from the time domain simulations. The mode shapes are categorized into seven distinct deformation patterns. An actual load case from the dynamometer tests, a 100% rated torque loading, is used in the time domain simulations. The results from this comprehensive study provide an insight into the proper modelling of a wind turbine Planet Carrier in a multi-body setting. Copyright © 2012 John Wiley & Sons, Ltd.

Yihan Xing - One of the best experts on this subject based on the ideXlab platform.

  • multi body modelling and analysis of a Planet Carrier in a wind turbine gearbox
    Wind Energy, 2013
    Co-Authors: Yihan Xing, Torgeir Moan
    Abstract:

    There have been some recent efforts to numerically model and analyse the wind turbine gearbox. To date, much of the focus has been on increasing model refinement and demonstrating its added value. This paper takes a step back and examines in detail the modelling and analysis of an important wind turbine gearbox component, the Planet Carrier, in a multi-body setting. The Planet Carrier studied in this work comes from the 750 kW wind turbine gearbox used in the National Renewable Energy Laboratory's Gearbox Reliability Collaborative project. The study is performed in two parts. First, the influence of subcomponents mated to the Planet Carrier in the gearbox assembly is investigated in detail. These components consist of the Planet pins, bearings and the main shaft. In the second part of the study, the flexible body modelling of the Planet Carrier for use in multi-body simulations is examined through the use of condensed finite element and multi-body simulation models. Both eigenvalue analyses and time domain simulations are performed. Comparisons are made regarding the eigenfrequencies, categorized mode shapes and the maximum and minimum Planet Carrier rim deflections from the time domain simulations. The mode shapes are categorized into seven distinct deformation patterns. An actual load case from the dynamometer tests, a 100% rated torque loading, is used in the time domain simulations. The results from this comprehensive study provide an insight into the proper modelling of a wind turbine Planet Carrier in a multi-body setting. Copyright © 2012 John Wiley & Sons, Ltd.

  • Modelling and analysis of the gearbox in a floating spar-type wind turbine
    2013
    Co-Authors: Yihan Xing
    Abstract:

    This thesis seeks to reveal and investigate important drivetrain dynamics in relation to offshore wind turbines. Emphasis is placed on drivetrains of the spar-type floating wind turbines (FWTs). FWTs are proposed to be used for offshore wind power extraction at the deeper-water sites where fixed foundations are economically infeasible. The FWT is a complex machine that is subjected to tough offshore environmental conditions and access for maintenance, repair and overhaul is limited and expensive. It is therefore important to understand the FWT drivetrain because gearbox failures have consistently plagued the wind energy industry and have not been able to reach the 20 year design life. Moreover, gearbox failures often result in massive downtime. Some industry players have even labelled the gearbox as the ’missing link’. There is a need for new insight into the understanding of drivetrain dynamics from an offshore perspective in order to improve its design and better predict its life. The findings in this thesis contribute to the de-risking process of offshore wind.The drivetrain and wind turbine from the National Renewable Energy Laboratory’s (NREL’s) Gearbox Reliability Collaborative (GRC) project are used as the case studies. There are three main topics in this thesis.In the first topic, the modelling of the Planet Carrier is investigated in detail. The study is performed in two parts. First, the influence of subcomponents mated to the Planet Carrier in the gearbox assembly is investigated in detail. These components consist of the Planet pins, bearings and the main shaft. In the second part of the study, the flexible body modelling of the Planet Carrier for use in multi-body simulations is examined through the use of condensed finite element and multi-body simulation models.The second topic is the collaborative work with NREL which compared the multi-body models with the measurements taken from the GRC test campaigns. Data from the Planetary stage is used to evaluate the accuracy and computation time of numerical models of the gearbox. A set of models that represent different levels of fidelity are established and compared to the measurement test results.The last topic, which is also the main topic, deals with the modelling and analysis of the FWT drivetrain. Various spar platforms with different drafts in the spar buoys and mooring line designs for the GRC wind turbine are specially designed for this purpose.A decoupled solution is used, i.e., the drivetrain is assumed to have no feedback on the rotor. Global aero-hydro-elastic-servo simulations are performed and the main shaft loads, generator speed and nacelle motions are calculated. These are used as inputs to a multi-body drivetrain model. Comparisons of the FWT and the land-based wind turbine (WT) are performed. Detailed sensitivity studies of the influences of the design parameters on the drivetrain loads and other wind turbine component loads are also performed.

  • Multi‐body modelling and analysis of a Planet Carrier in a wind turbine gearbox
    Wind Energy, 2012
    Co-Authors: Yihan Xing, Torgeir Moan
    Abstract:

    There have been some recent efforts to numerically model and analyse the wind turbine gearbox. To date, much of the focus has been on increasing model refinement and demonstrating its added value. This paper takes a step back and examines in detail the modelling and analysis of an important wind turbine gearbox component, the Planet Carrier, in a multi-body setting. The Planet Carrier studied in this work comes from the 750 kW wind turbine gearbox used in the National Renewable Energy Laboratory's Gearbox Reliability Collaborative project. The study is performed in two parts. First, the influence of subcomponents mated to the Planet Carrier in the gearbox assembly is investigated in detail. These components consist of the Planet pins, bearings and the main shaft. In the second part of the study, the flexible body modelling of the Planet Carrier for use in multi-body simulations is examined through the use of condensed finite element and multi-body simulation models. Both eigenvalue analyses and time domain simulations are performed. Comparisons are made regarding the eigenfrequencies, categorized mode shapes and the maximum and minimum Planet Carrier rim deflections from the time domain simulations. The mode shapes are categorized into seven distinct deformation patterns. An actual load case from the dynamometer tests, a 100% rated torque loading, is used in the time domain simulations. The results from this comprehensive study provide an insight into the proper modelling of a wind turbine Planet Carrier in a multi-body setting. Copyright © 2012 John Wiley & Sons, Ltd.

Jan Helsen - One of the best experts on this subject based on the ideXlab platform.

  • Assessment of excitation mechanisms and structural flexibility influence in excitation propagation in multi-megawatt wind turbine gearboxes: Experiments and flexible multibody model optimization
    Mechanical Systems and Signal Processing, 2013
    Co-Authors: Jan Helsen, Ben Marrant, Frederik Vanhollebeke, Filip De Coninck, Dries Berckmans, Dirk Vandepitte, Wim Desmet
    Abstract:

    Reliable gearbox design calculations require sufficient insight in gearbox dynamics, which is determined by the interaction between the different excitation mechanisms and the gearbox modal behavior. Both external gearbox excitation originating from the wind turbine drive train and internal gearbox excitation are important. Moreover with regard to the modal behavior the different gearbox structural components: Planet Carrier, shafts and housing are of influence. The main objective of this article is the experimental investigation of the interaction between the different excitation mechanisms and the gearbox modal behavior. The insights gathered are used to prove the need for accurate gear mesh representation and structural flexibility within the corresponding flexible multibody gearbox simulation model. Experiments are conducted on a dynamic 13.2 MW test facility on which two multi-megawatt wind turbine gearboxes are placed back to back and subjected to a speed run-up. Measurement sensors consist of bearing displacement sensors, torque sensors, encoders and accelerometers distributed over the gearbox. Excitation order amplitudes on different locations in the gearbox are determined by means of a Time Varying Discrete Fourier Transform (TVDFT) order tracking on the measured sensor signals. Moreover the propagation of this excitation throughout the gearbox is assessed. Relating the orders to the corresponding excitation source allows the definition of order influence regions within the gearbox. The interaction between the gear mesh order excitation and structural flexibility is shown. © 2013 Elsevier Ltd.

  • Multibody modelling of varying complexity for modal behaviour analysis of wind turbine gearboxes
    Renewable Energy, 2011
    Co-Authors: Jan Helsen, Ben Marrant, Frederik Vanhollebeke, Dirk Vandepitte, Wim Desmet
    Abstract:

    In the currently booming market of wind turbines, a clear focus is put on the design of reliable and cost-effective subsystems, such as the gearbox. A requirement for reliable gearbox design calculations is sufficient insight in the dynamics of the entire wind turbine drive train. Since traditional wind turbine design codes reduce the drive train to just a few degrees of freedom, considerable research effort is spent in advanced modelling and simulation techniques to gain more insights in the dynamics at hand. This work focusses on the gearbox modal behaviour assessment by means of three more complex modelling techniques of varying complexity: the purely torsional-, rigid six degree of freedom with discrete flexibility and flexible multibody technique. Both simulation and experimental results are discussed. Typical mode categories for traditional wind turbine gearboxes are defined. Moreover the challenge of the definition of an accurate approach to condense finite element models for representing the flexible components in the flexible multibody models is overcome. Furthermore the interaction between the structural modes of the Planet Carrier and Planetary ring flexibility with the overall gearbox modes is investigated, resulting in the definition of two new mode categories: the Planet Carrier modes and Planetary ring modes.

  • The influence of flexibility within multibody modeling of multi-megawatt wind turbine gearboxes
    2008
    Co-Authors: Jan Helsen, Dirk Vandepitte, Gert Heirman, Wim Desmet
    Abstract:

    This work discusses the influence of flexibility within the multibody approach for wind-turbine gearbox modeling and validates them, by means of a generic gearbox calculation consisting of one Planetary gear stage and two helical stages. First the state-of-the-art rigid multibody modeling with discrete flexibility is discussed. Secondly flexible multibody modeling by means of reduced finite element models is discussed. The different structures for coupling the reduced finite element structure to the multibody gearbox model are investigated. The modal behavior of a fully flexible model of the high speed helical gear stage is determined and compared to the rigid model. A detailed estimation of the influence of the flexibility of the different components of the Planetary stage is performed. Finally a flexible Planet Carrier is introduced in the full gearbox model and a comparison with the rigid full gearbox model is made

Dirk Vandepitte - One of the best experts on this subject based on the ideXlab platform.

  • Assessment of excitation mechanisms and structural flexibility influence in excitation propagation in multi-megawatt wind turbine gearboxes: Experiments and flexible multibody model optimization
    Mechanical Systems and Signal Processing, 2013
    Co-Authors: Jan Helsen, Ben Marrant, Frederik Vanhollebeke, Filip De Coninck, Dries Berckmans, Dirk Vandepitte, Wim Desmet
    Abstract:

    Reliable gearbox design calculations require sufficient insight in gearbox dynamics, which is determined by the interaction between the different excitation mechanisms and the gearbox modal behavior. Both external gearbox excitation originating from the wind turbine drive train and internal gearbox excitation are important. Moreover with regard to the modal behavior the different gearbox structural components: Planet Carrier, shafts and housing are of influence. The main objective of this article is the experimental investigation of the interaction between the different excitation mechanisms and the gearbox modal behavior. The insights gathered are used to prove the need for accurate gear mesh representation and structural flexibility within the corresponding flexible multibody gearbox simulation model. Experiments are conducted on a dynamic 13.2 MW test facility on which two multi-megawatt wind turbine gearboxes are placed back to back and subjected to a speed run-up. Measurement sensors consist of bearing displacement sensors, torque sensors, encoders and accelerometers distributed over the gearbox. Excitation order amplitudes on different locations in the gearbox are determined by means of a Time Varying Discrete Fourier Transform (TVDFT) order tracking on the measured sensor signals. Moreover the propagation of this excitation throughout the gearbox is assessed. Relating the orders to the corresponding excitation source allows the definition of order influence regions within the gearbox. The interaction between the gear mesh order excitation and structural flexibility is shown. © 2013 Elsevier Ltd.

  • Multibody modelling of varying complexity for modal behaviour analysis of wind turbine gearboxes
    Renewable Energy, 2011
    Co-Authors: Jan Helsen, Ben Marrant, Frederik Vanhollebeke, Dirk Vandepitte, Wim Desmet
    Abstract:

    In the currently booming market of wind turbines, a clear focus is put on the design of reliable and cost-effective subsystems, such as the gearbox. A requirement for reliable gearbox design calculations is sufficient insight in the dynamics of the entire wind turbine drive train. Since traditional wind turbine design codes reduce the drive train to just a few degrees of freedom, considerable research effort is spent in advanced modelling and simulation techniques to gain more insights in the dynamics at hand. This work focusses on the gearbox modal behaviour assessment by means of three more complex modelling techniques of varying complexity: the purely torsional-, rigid six degree of freedom with discrete flexibility and flexible multibody technique. Both simulation and experimental results are discussed. Typical mode categories for traditional wind turbine gearboxes are defined. Moreover the challenge of the definition of an accurate approach to condense finite element models for representing the flexible components in the flexible multibody models is overcome. Furthermore the interaction between the structural modes of the Planet Carrier and Planetary ring flexibility with the overall gearbox modes is investigated, resulting in the definition of two new mode categories: the Planet Carrier modes and Planetary ring modes.

  • The influence of flexibility within multibody modeling of multi-megawatt wind turbine gearboxes
    2008
    Co-Authors: Jan Helsen, Dirk Vandepitte, Gert Heirman, Wim Desmet
    Abstract:

    This work discusses the influence of flexibility within the multibody approach for wind-turbine gearbox modeling and validates them, by means of a generic gearbox calculation consisting of one Planetary gear stage and two helical stages. First the state-of-the-art rigid multibody modeling with discrete flexibility is discussed. Secondly flexible multibody modeling by means of reduced finite element models is discussed. The different structures for coupling the reduced finite element structure to the multibody gearbox model are investigated. The modal behavior of a fully flexible model of the high speed helical gear stage is determined and compared to the rigid model. A detailed estimation of the influence of the flexibility of the different components of the Planetary stage is performed. Finally a flexible Planet Carrier is introduced in the full gearbox model and a comparison with the rigid full gearbox model is made