Inflow and Fatigue Response of the NWTC Advanced Research Turbine

2003 ◽  
Author(s):  
Herbert J. Sutherland ◽  
Neil D. Kelley ◽  
M. Maureen Hand
Keyword(s):  
Test List ◽  
Structural Response ◽  
Synchronous Generator ◽  
Measurement Unit ◽  
Response Data ◽  
Extreme Loads ◽  
Sonic Anemometers ◽  
Planar Array ◽  
Fatigue Loads

The Long-term Inflow and Structural Test (LIST) program is collecting long-term inflow and structural response data to characterize the spectrum of loads on wind turbines. In one of the measurement campaigns being conducted under this program, the 42-m diameter, 600-kW NWTC Advanced Research Turbine (ART) was monitored. The turbine is an upwind, two-bladed teetered-hub machine. It has full span pitch control and a synchronous generator. The inflow was monitored with a planar array of five high-resolution sonic anemometers and supporting meteorological instrumentation located 1.5 diameters upwind of the turbine. The structural response of the turbine was measured using strain gauge circuits and an inertial measurement unit (IMU). The former were used to monitor root bending moments and the low-speed shaft torque, while the latter was used to monitor the motion of the tower and the nacelle. Auxiliary gauges measured blade pitch, rotor teeter, nacelle yaw and generator power. A total of 3299 10-minute records were collected for analysis. From this set, 1044 records are used to examine the influence of various inflow parameters on fatigue loads. Long-term fatigue loads and extreme loads are also examined.

Inflow and the Fatigue of the LIST Wind Turbine

2002 ◽  
Author(s):  
Herbert J. Sutherland
Keyword(s):  
Test List ◽  
Vertical Component ◽  
Structural Response ◽  
Structural Data ◽  
Reynolds Stresses ◽  
Load Spectrum ◽  
Fatigue Load ◽  
Obukhov Length ◽  
Fatigue Loads

The Long-term Inflow and Structural Test (LIST) program is collecting long-term, continuous inflow and structural response data to characterize the spectrum of loads on wind turbines. A heavily instrumented Micon 65/13M turbine with SERI 8m blades is being used as the primary test turbine for this test. This turbine is located in Bushland, TX, a test site that exposes the turbine to a wind regime representative of a Great Plains commercial site. The turbine and inflow are being characterized with 60 measurements: 34 to characterize the inflow, 19 to characterize structural response, and 7 to characterize the time-varying state of the turbine. In this paper, the inflow and structural data from this measurement campaign are analyzed to determine the correlation of various inflow descriptors with fatigue loads. The inflow is described by various parameters, including the mean, standard deviation, skewness and kurtosis of the wind speed, turbulence intensity, turbulence length scales, Reynolds stresses, local friction velocity, Obukhov length and the gradient Richardson number. The fatigue load spectrum corresponding to these parameters is characterized as an equivalent fatigue load. A regression analysis is then used to determine which parameters are correlated to the fatigue loads. The results illustrate that the vertical component of the inflow is the most important of the secondary inflow parameters on fatigue loads. Long-term fatigue spectra illustrate that extrapolation of relatively short-term data to longer times is consistent for the data reported here.

Analysis of the Structural and Inflow Data From the List Turbine

2002 ◽  
Vol 124 (4) ◽  
pp. 432-445 ◽  
Author(s):  
Herbert J. Sutherland
Keyword(s):  
Test List ◽  
Vertical Component ◽  
Structural Response ◽  
Horizontal Wind ◽  
Reynolds Stresses ◽  
Load Spectrum ◽  
Fatigue Load ◽  
Horizontal Wind Speed ◽  
Fatigue Loads

The Long-term Inflow and Structural Test (LIST) program is collecting long-term, continuous inflow and structural response data to characterize the spectrum of loads on wind turbines. A heavily instrumented Micon 65/13M turbine with Phoenix 8m blades is being used as the test turbine for the first measurement campaign of this program. This turbine is located in Bushland, TX, a test site that exposes the turbine to a wind regime representative of a Great Plains commercial site. The turbine and inflow are being characterized with 60 measurements: 34 to characterize the inflow, 19 to characterize structural response, and seven to characterize the time-varying state of the turbine. In this paper, an analysis of the structural and inflow data is presented. Particular attention is paid to the determination of the various structural loads on the turbine, long-term fatigue spectra and the correlation of various inflow descriptors with fatigue loads. For the latter analysis, the inflow is described by various parameters, including the mean, standard deviation, skewness and kurtosis of the hub-height horizontal wind speed, turbulence intensity, turbulence length scales, Reynolds stresses, local friction velocity, Obukhov length, and the gradient Richardson number. The fatigue load spectrum corresponding to these parameters is characterized as an equivalent fatigue load. A regression analysis is then used to determine which parameters are correlated to the fatigue loads. The results illustrate that the vertical component of the inflow is the most important of the secondary inflow parameters with respect to fatigue loads. Long-term fatigue spectra illustrate that extrapolation of relatively short-term data to longer times is consistent for the data reported here.

Statistical Analysis of Wind Turbine Inflow and Structural Response Data from the LIST Program

2003 ◽  
Vol 125 (4) ◽  
pp. 541-550 ◽  
Author(s):  
Luke D. Nelson ◽  
Lance Manuel ◽  
Herbert J. Sutherland ◽  
Paul S. Veers
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Test List ◽  
Structural Response ◽  
Vertical Shear ◽  
Horizontal Wind ◽  
Parameter Vector ◽  
Response Data ◽  
Extreme Loads ◽  
Extreme Load

The Long-Term Inflow and Structural Test (LIST) program is gathering inflow and structural response data on a modified version of the Micon 65/13 wind turbine at a test site near Bushland, Texas. Data from 491 ten-minute time data records are analyzed here to determine the dependency of fatigue and extreme loads on inflow parameters. Flap and edge bending moment ranges at a blade root are chosen as the structural response variable, z. Various parameters related to the inflow (including, for example, primary parameters such as the mean and standard deviation of the hub-height horizontal wind speed, and secondary parameters such as Reynolds stresses, vertical shear exponent, etc.) are each considered in an inflow parameter vector, x. Time series for the structural response, z, are processed in order to obtain a structural response parameter, y, where in separate statistical studies, y is taken to be either an equivalent fatigue load or an extreme load. This study describes a procedure by which the important “dependencies” of y on the various variables contained in the inflow parameter vector, x, may be determined considering all the available data. These dependencies of y on x are then recomputed using only the data with above-rated mean wind speeds (taken to be approximately 13 m/s). The procedure employed is similar to other studies, but we do not bin the data sets by wind speed since dependencies in one wind speed bin may be different from those in other bins. Also, our procedure, in sharp contrast to previous studies, examines each inflow parameter in the vector, x, in a sequential analysis, rather than by using multivariate regression. Results from the present study suggest that the primary inflow parameters have a small amount of predictive power in establishing fatigue and extreme loads. In addition, large correlations that exist between several of the secondary parameters individually and each of the primary parameters make it difficult for the secondary parameters to provide any additional explanation of turbine response once the primary parameters have been accounted for.

The NREL Large-Scale Turbine Inflow and Response Experiment: Preliminary Results

2002 ◽  
Author(s):  
Neil Kelley ◽  
Maureen Hand ◽  
Scott Larwood ◽  
Ed McKenna
Keyword(s):  
Wind Turbine ◽  
Large Scale ◽  
Structural Response ◽  
Technology Center ◽  
Operating Environments ◽  
Sonic Anemometers ◽  
Wide Range ◽  
Scaling Parameters ◽  
Planar Array ◽  
Turbulence Scaling

The accurate numerical dynamic simulation of new large-scale wind turbine designs operating over a wide range of inflow environments is critical because it is usually impractical to test prototypes in a variety of locations. Large turbines operate in a region of the atmospheric boundary layer that currently may not be adequately simulated by present turbulence codes. In this paper, we discuss the development and use of a 42-m (137-ft) planar array of five, high-resolution sonic anemometers upwind of a 600-kW wind turbine at the National Wind Technology Center (NWTC). The objective of this experiment is to obtain simultaneously collected turbulence information from the inflow array and the corresponding structural response of the turbine. The turbulence information will be used for comparison with that predicted by currently available codes and establish any systematic differences. These results will be used to improve the performance of the turbulence simulations. The sensitivities of key elements of the turbine aeroelastic and structural response to a range of turbulence-scaling parameters will be established for comparisons with other turbines and operating environments. In this paper, we present an overview of the experiment, and offer examples of two observed cases of inflow characteristics and turbine response collected under daytime and nighttime conditions, and compare their turbulence properties with predictions.

Probabilistic Analysis of LIST Data for the Estimation of Extreme Design Loads for Wind Turbine Components*†

2003 ◽  
Vol 125 (4) ◽  
pp. 531-540 ◽  
Author(s):  
M. D. Pandey ◽  
H. J. Sutherland
Keyword(s):  
Wind Turbine ◽  
Sampling Error ◽  
Test List ◽  
Structural Data ◽  
Value Theory ◽  
Extreme Value ◽  
Sampling Errors ◽  
Extreme Loads ◽  
Design Loads

The robust estimation of wind turbine design loads for service lifetimes of 30 to 50 years that are based on limited field measurements is a challenging problem. Estimating the long-term load distribution involves the integration of conditional distributions of extreme loads over the mean wind speed and turbulence intensity distributions. However, the accuracy of the statistical extrapolation can be sensitive to both model and sampling errors. Using measured inflow and structural data from the Long Term Inflow and Structural Test (LIST) program, this paper presents a comparative assessment of extreme loads using three distributions: namely, the Gumbel, Weibull and Generalized Extreme Value distributions. The paper uses L-moments, in place of traditional product moments, with the purpose of reducing the sampling error. The paper discusses the effects of modeling and sampling errors and highlights the practical limitations of extreme value theory.

scholarly journals Statistical Analysis of Inflow and Structural Response Data From the LIST Program

2003 ◽  
Author(s):  
Luke D. Nelson ◽  
Lance Manuel ◽  
Herbert J. Sutherland ◽  
Paul S. Veers
Keyword(s):  
Wind Speed ◽  
Sequential Analysis ◽  
Test List ◽  
Structural Response ◽  
Vertical Shear ◽  
Horizontal Wind ◽  
Parameter Vector ◽  
Time Data ◽  
Response Data ◽  
Extreme Load

The Long-Term Inflow and Structural Test (LIST) program is gathering inflow and structural response data on a modified version of the Micon 65/13 wind turbine at a test site near Bushland, Texas. Data from 491 ten-minute time data records are analyzed here to determine the dependency of fatigue and extreme loads on inflow parameters. Flap and edge bending moment ranges at a blade root are chosen as the structural response variable, z. Various parameters related to the inflow (including, for example, primary parameters, the mean and standard deviation of the hub-height horizontal wind speed, and secondary parameters, Reynolds stresses, vertical shear exponent, etc.) are each considered in an inflow parameter vector, x. Time series for the structural response, z, are processed in order to obtain a structural response parameter, y, where in separate statistical studies, y is taken to be either an equivalent fatigue load or an extreme load. This paper first describes a procedure by which the important “dependencies” of y on the various variables contained in the inflow parameter vector, x, may be determined considering all the available data. These dependencies of y on x are then recomputed using only the data with above-rated mean wind speeds (taken to be approximately 13 m/s). The procedure employed is similar to other previous studies, but we do not bin the data sets by wind speed since dependencies in one wind speed bin may be different from those in other bins. Also, our procedure, in sharp contrast to previous studies, examines each inflow parameter in the vector, x, in a sequential analysis, rather than by using multivariate regression.

A New Approach to Elastodynamic Response of Cylindrical Shell Based on Generalized Solution Structure Theorem for Wave Equation

2010 ◽  
Author(s):  
Shugen Xu ◽  
Weiqiang Wang ◽  
Yan Liu
Keyword(s):  
Wave Equation ◽  
Solution Structure ◽  
Structure Theorem ◽  
Dynamic Pressure ◽  
Structural Response ◽  
Generalized Solution ◽  
New Approach ◽  
Response Data ◽  
Elastodynamic Response ◽  
Detailed Derivation

In this paper, a generalized solution structure theorem has been provided. It can be use to solve the wave equation about the structural response of cylinder under the dynamic pressure. This new approach also can be used to solve a batch of partial differential equations with the similar form. A detailed derivation process has been given to show how the solution is obtained. Finally, a practical example is presented, and all the elastodynamic response data at any point during dynamic pressure can be acquired conveniently.

scholarly journals A Novel Monitoring Navigation Method for Cold Atom Interference Gyroscope

Sensors ◽  
2019 ◽  
Vol 19 (2) ◽  
pp. 222 ◽  
Author(s):  
Lin Zhang ◽  
Wei Gao ◽  
Qian Li ◽  
Runbing Li ◽  
Zhanwei Yao ◽  
...  
Keyword(s):  
Navigation System ◽  
Inertial Measurement Unit ◽  
Cold Atom ◽  
Measurement Unit ◽  
Simulation Test ◽  
Filtering Technique ◽  
High Dynamic ◽  
Novel Design ◽  
Navigation Method

The implementation principle of a typical three-pulse cold atom interference gyroscope is introduced in this paper. Based on its configuration and current research status, the problems of cold atom interference gyro are pointed out. The data-rate is insufficient, and it is difficult to achieve high dynamic measurement. Then, based on these two limitations, a novel design of the monitoring navigation system of the cold atom interference gyroscope (CAIG) and an intermediate-grade inertial measurement unit (IMU) was proposed to obtain the long-term position result without GPS signals, such as the Inertial Navigation System (INS) in underwater vehicles. While the CAIG was used as the external gyro, the bias of IMU and the misalignment angle between the CAIG-frame and the IMU-frame are obtained through filtering technique. The simulation test and field test demonstrated the improvements of the long-term positioning accuracy of the INS.

scholarly journals Response of instrumented buildings under the 2016 Kaikoura earthquake

2017 ◽  
Vol 50 (2) ◽  
pp. 237-252 ◽  
Author(s):  
Reagan Chandramohan ◽  
Quincy Ma ◽  
Liam M. Wotherspoon ◽  
Brendon A. Bradley ◽  
Mostafa Nayyerloo ◽  
...  
Keyword(s):  
Structural Response ◽  
Strong Motion ◽  
Period Range ◽  
Motion Data ◽  
Response Data ◽  
Vibrational Characteristics ◽  
Modelling Techniques ◽  
S Period ◽  
Upper South ◽  
Kaikoura Earthquake

Six buildings in the Wellington region and the upper South Island, instrumented as part of the GeoNet Building Instrumentation Programme, recorded strong motion data during the 2016 Kaikoura earthquake. The response of two of these buildings: the Bank of New Zealand (BNZ) Harbour Quays, and Ministry of Business, Innovation, and Employment (MBIE) buildings, are examined in detail. Their acceleration and displacement response was reconstructed from the recorded data, and their vibrational characteristics were examined by computing their frequency response functions. The location of the BNZ building in the CentrePort region on the Wellington waterfront, which experienced significant ground motion amplification in the 1–2 s period range due to site effects, resulted in the imposition of especially large demands on the building. The computed response of the two buildings are compared to the intensity of ground motions they experienced and the structural and nonstructural damage they suffered, in an effort to motivate the use of structural response data in the validation of performance objectives of building codes, structural modelling techniques, and fragility functions. Finally, the nature of challenges typically encountered in the interpretation of structural response data are highlighted.

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