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Assessment Of Wind Parameter Sensitivity On Ultimate And Fatigue Wind Turbine Loads Preprint
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Book Synopsis Assessment of Wind Parameter Sensitivity on Ultimate and Fatigue Wind Turbine Loads: Preprint by :
Download or read book Assessment of Wind Parameter Sensitivity on Ultimate and Fatigue Wind Turbine Loads: Preprint written by and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wind turbines are designed using a set of simulations to ascertain the structural loads that the turbine could encounter. While mean hub-height wind speed is considered to vary, other wind parameters such as turbulence spectra, sheer, veer, spatial coherence, and component correlation are fixed or conditional values that, in reality, could have different characteristics at different sites and have a significant effect on the resulting loads. This paper therefore seeks to assess the sensitivity of different wind parameters on the resulting ultimate and fatigue loads on the turbine during normal operational conditions. Eighteen different wind parameters are screened using an Elementary Effects approach with radial points. As expected, the results show a high sensitivity of the loads to the turbulence standard deviation in the primary wind direction, but the sensitivity to wind shear is often much greater. To a lesser extent, other wind parameters that drive loads include the coherence in the primary wind direction and veer.
Book Synopsis Assessment of Airfoil Property Sensitivity on Wind Turbine Extreme and Fatigue Loads: Preprint by :
Download or read book Assessment of Airfoil Property Sensitivity on Wind Turbine Extreme and Fatigue Loads: Preprint written by and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wind turbines are designed using a set of simulations to determine the structural loads that the turbine could experience. These structural loads can be significant influenced by physical turbine parameters. While significant research and effort has been put into measuring and defining such parameters, limited work has been done to quantify the sensitivity of structural loads to uncertainty in the physical turbine parameters. This paper therefore seeks to assess the sensitivity of different turbine aerodynamic parameters on the resulting ultimate and fatigue loads of the turbine during normal operational conditions. Eighteen different turbine parameters are screened using an Elementary Effects approach with radial points. The results show a high sensitivity of the loads to the blade twist and lift coefficient distributions. To a lesser extent, other turbine parameters that drive loads include the maximum lift coefficient location, blade chord length, and drag coefficient distributions.
Book Synopsis Assessment of Airfoil Property Sensitivity on Wind Turbine Extreme and Fatigue Loads by : Rick Damiani
Download or read book Assessment of Airfoil Property Sensitivity on Wind Turbine Extreme and Fatigue Loads written by Rick Damiani and published by . This book was released on 2019 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Fatigue Life Prediction for Wind Turbines by : TD. Ashwill
Download or read book Fatigue Life Prediction for Wind Turbines written by TD. Ashwill and published by . This book was released on 1994 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wind turbines are fatigue-critical machines used to produce electrical energy from the wind. These rotating machines are subjected to combinations of wind, gravity, and gyroscopic loadings that are highly irregular in nature. Historical examples of fatigue problems in both research and commercial wind-turbine development are presented. Some example data on wind-turbine environments, loadings, and material properties are also shown. Before a description of how the authors have chosen to attack the cumulative damage assessment, questions are presented for the reader's reflection. The solution technique used by the authors to define the loading spectrum for wind turbines is then presented. Special emphasis is placed on the development of a loading spectrum for use in the fatigue analysis. Less attention is paid to methods of cumulative damage assessment; Miner's rule and constant amplitude S-n data are used. A case study then applies the procedures to an actual wind-turbine blade joint. The wind turbine is the 34-m diameter vertical axis wind turbine (VAWT) erected by Sandia National Laboratories near Bushland, TX. The case study examines parameter sensitivities for realistic uncertainties in inputs defining the turbine environment, stress response, and material properties. The fatigue lifetimes are calculated using a fatigue analysis program, called LIFE2, which was developed at Sandia.
Book Synopsis Usage of Parameterized Fatigue Spectra and Physics-Based Systems Engineering Models for Wind Turbine Component Sizing: Preprint by :
Download or read book Usage of Parameterized Fatigue Spectra and Physics-Based Systems Engineering Models for Wind Turbine Component Sizing: Preprint written by and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Software models that use design-level input variables and physics-based engineering analysis for estimating the mass and geometrical properties of components in large-scale machinery can be very useful for analyzing design trade-offs in complex systems. This study uses DriveSE, an OpenMDAO-based drivetrain model that uses stress and deflection criteria to size drivetrain components within a geared, upwind wind turbine. Because a full lifetime fatigue load spectrum can only be defined using computationally-expensive simulations in programs such as FAST, a parameterized fatigue loads spectrum that depends on wind conditions, rotor diameter, and turbine design life has been implemented. The parameterized fatigue spectrum is only used in this paper to demonstrate the proposed fatigue analysis approach. This paper details a three-part investigation of the parameterized approach and a comparison of the DriveSE model with and without fatigue analysis on the main shaft system. It compares loads from three turbines of varying size and determines if and when fatigue governs drivetrain sizing compared to extreme load-driven design. It also investigates the model's sensitivity to shaft material parameters. The intent of this paper is to demonstrate how fatigue considerations in addition to extreme loads can be brought into a system engineering optimization.
Book Synopsis Probabilistic Fatigue Methodology and Wind Turbine Reliability by :
Download or read book Probabilistic Fatigue Methodology and Wind Turbine Reliability written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Wind turbines subjected to highly irregular loadings due to wind, gravity, and gyroscopic effects are especially vulnerable to fatigue damage. The objective of this study is to develop and illustrate methods for the probabilistic analysis and design of fatigue-sensitive wind turbine components. A computer program (CYCLES) that estimates fatigue reliability of structural and mechanical components has been developed. A FORM/SORM analysis is used to compute failure probabilities and importance factors of the random variables. The limit state equation includes uncertainty in environmental loading, gross structural response, and local fatigue properties. Several techniques are shown to better study fatigue loads data. Common one-parameter models, such as the Rayleigh and exponential models are shown to produce dramatically different estimates of load distributions and fatigue damage. Improved fits may be achieved with the two-parameter Weibull model. High b values require better modeling of relatively large stress ranges; this is effectively done by matching at least two moments (Weibull) and better by matching still higher moments. For this purpose, a new, four-moment[open-quotes]generalized Weibull[close-quotes] model is introduced. Load and resistance factor design (LRFD) methodology for design against fatigue is proposed and demonstrated using data from two horizontal-axis wind turbines. To estimate fatigue damage, wind turbine blade loads have been represented by their first three statistical moments across a range of wind conditions. Based on the moments[mu][sub 1][hor-ellipsis][mu][sub 3], new[open-quotes]quadratic Weibull[close-quotes] load distribution models are introduced. The fatigue reliability is found to be notably affected by the choice of load distribution model.
Book Synopsis Assessing Fatigue and Ultimate Load Uncertainty in Floating Offshore Wind Turbines Due to Varying Simulation Length by :
Download or read book Assessing Fatigue and Ultimate Load Uncertainty in Floating Offshore Wind Turbines Due to Varying Simulation Length written by and published by . This book was released on 2013 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the push towards siting wind turbines farther offshore due to higher wind quality and less visibility, floating offshore wind turbines, which can be located in deep water, are becoming an economically attractive option. The International Electrotechnical Commission's (IEC) 61400-3 design standard covers fixed-bottom offshore wind turbines, but there are a number of new research questions that need to be answered to modify these standards so that they are applicable to floating wind turbines. One issue is the appropriate simulation length needed for floating turbines. This paper will discuss the results from a study assessing the impact of simulation length on the ultimate and fatigue loads of the structure, and will address uncertainties associated with changing the simulation length for the analyzed floating platform. Recommendations of required simulation length based on load uncertainty will be made and compared to current simulation length requirements.
Book Synopsis Sensitivity analysis of wind plant performance to key turbine design parameters by : Katherine Dykes
Download or read book Sensitivity analysis of wind plant performance to key turbine design parameters written by Katherine Dykes and published by . This book was released on 2014 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Sensitivity Analysis of Wind Plant Performance to Key Turbine Design Parameters by :
Download or read book Sensitivity Analysis of Wind Plant Performance to Key Turbine Design Parameters written by and published by . This book was released on 2014 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper introduces the development of a new software framework for research, design, and development of wind energy systems which is meant to 1) represent a full wind plant including all physical and nonphysical assets and associated costs up to the point of grid interconnection, 2) allow use of interchangeable models of varying fidelity for different aspects of the system, and 3) support system level multidisciplinary analyses and optimizations. This paper describes the design of the overall software capability and applies it to a global sensitivity analysis of wind turbine and plant performance and cost. The analysis was performed using three different model configurations involving different levels of fidelity, which illustrate how increasing fidelity can preserve important system interactions that build up to overall system performance and cost. Analyses were performed for a reference wind plant based on the National Renewable Energy Laboratory's 5-MW reference turbine at a mid-Atlantic offshore location within the United States.
Book Synopsis A Case for Including Atmospheric Thermodynamic Variables in Wind Turbine Fatigue Loading Parameter Identification by :
Download or read book A Case for Including Atmospheric Thermodynamic Variables in Wind Turbine Fatigue Loading Parameter Identification written by and published by . This book was released on 1999 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper makes the case for establishing efficient predictor variables for atmospheric thermodynamics that can be used to statistically correlate the fatigue accumulation seen on wind turbines. Recently, two approaches to this issue have been reported. One uses multiple linear-regression analysis to establish the relative causality between a number of predictors related to the turbulent inflow and turbine loads. The other approach, using many of the same predictors, applies the technique of principal component analysis. An examination of the ensemble of predictor variables revealed that they were all kinematic in nature; i.e., they were only related to the description of the velocity field. Boundary-layer turbulence dynamics depends upon a description of the thermal field and its interaction with the velocity distribution. We used a series of measurements taken within a multi-row wind farm to demonstrate the need to include atmospheric thermodynamic variables as well as velocity-related ones in the search for efficient turbulence loading predictors in various turbine-operating environments. Our results show that a combination of vertical stability and hub-height mean shearing stress variables meet this need over a period of 10 minutes.
Book Synopsis Parametric Models for Estimating Wind Turbine Fatigue Loads for Design by :
Download or read book Parametric Models for Estimating Wind Turbine Fatigue Loads for Design written by and published by . This book was released on 2000 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Atmospheric and wake turbulence impacts on wind turbine fatigue loading by :
Download or read book Atmospheric and wake turbulence impacts on wind turbine fatigue loading written by and published by . This book was released on 2011 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Sensitivity of Modal Parameters of an Offshore Wind Turbine to Operational and Environmental Factors: A Numerical Study: Preprint by :
Download or read book Sensitivity of Modal Parameters of an Offshore Wind Turbine to Operational and Environmental Factors: A Numerical Study: Preprint written by and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The dynamics and performance of offshore wind turbines are sensitive to their structural properties, and in particular their modal parameters, i.e., natural frequencies, damping ratios and mode shapes. In this work, the sensitivity of the modal parameters of a 6 MW fixed-bottom offshore wind turbine to different operational and environmental conditions including wind speed and rotor speed is investigated. Effect of blade flexibility on the modal parameters of the system is also studied.
Book Synopsis A Case for Including Atmospheric Thermodynamic Variables in Wind Turbine Fatigue Loading Parameter Identification by : Neil Davis Kelley
Download or read book A Case for Including Atmospheric Thermodynamic Variables in Wind Turbine Fatigue Loading Parameter Identification written by Neil Davis Kelley and published by . This book was released on 1999 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Application of Measured Loads to Wind Turbine Fatigue and Reliability Analysis by :
Download or read book Application of Measured Loads to Wind Turbine Fatigue and Reliability Analysis written by and published by . This book was released on 1997 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cyclic loadings produce progressive damage that can ultimately result in wind turbine structural failure. There are many issues that must be dealt with in turning load measurements into estimates of component fatigue life. This paper deals with how the measured loads can be analyzed and processed to meet the needs of both fatigue life calculations and reliability estimates. It is recommended that moments of the distribution of rainflow-range load amplitudes be calculated and used to characterize the fatigue loading. These moments reflect successively more detailed physical characteristics of the loading (mean, spread, tail behavior). Moments can be calculated from data samples and functional forms can be fitted to wind conditions, such as wind speed and turbulence intensity, with standard recession techniques. Distributions of load amplitudes that accurately reflect the damaging potential of the loadings can be estimated from the moments at any, wind condition of interest. Fatigue life can then be calculated from the estimated load distributions, and the overall, long-term, or design spectrum can be generated for any particular wind-speed distribution. Characterizing the uncertainty in the distribution of cyclic loads is facilitated by using a small set of descriptive statistics for which uncertainties can be estimated. The effects of loading parameter uncertainty can then be transferred to the fatigue life estimate and compared with other uncertainties, such as material durability.
Book Synopsis A Case for Including Atmospheric Thermodynamic Variables in Wind Turbine Fatigue Loading Parameter Identification by : Neil Davis Kelley
Download or read book A Case for Including Atmospheric Thermodynamic Variables in Wind Turbine Fatigue Loading Parameter Identification written by Neil Davis Kelley and published by . This book was released on 1999 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Refinements and Tests of an Advanced Controller to Mitigate Fatigue Loads in the Controls Advanced Research Turbine by :
Download or read book Refinements and Tests of an Advanced Controller to Mitigate Fatigue Loads in the Controls Advanced Research Turbine written by and published by . This book was released on 2010 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wind turbines are complex, nonlinear, dynamic systems forced by aerodynamic, gravitational, centrifugal, and gyroscopic loads. The aerodynamics of wind turbines are nonlinear, unsteady, and complex. Turbine rotors are subjected to a complicated 3-D turbulent wind inflow field, with imbedded coherent vortices that drive fatigue loads and reduce lifetime. Design of control algorithms for wind turbines must account for multiple control objectives. Future large multi-megawatt turbines must be designed with lighter weight structures, using active controls to mitigate fatigue loads, while maximizing energy capture. Active damping should be added to these dynamic structures to maintain stability for operation in a complex environment. At the National Renewable Energy Laboratory (NREL), we have designed, implemented, and tested advanced controls to maximize energy extraction and reduce structural dynamic loads. These control designs are based on linear models of the turbine that are generated by specialized modeling software. In this paper, we present field test results of an advanced control algorithm to mitigate blade, tower, and drivetrain loads in Region 3.
