scholarly journals Measurements of high-frequency Atmospheric Turbulence and its Impact on the Boundary Layer of Wind Turbine Blades

2018 ◽  
Author(s):  
Alois Peter Schaffarczyk ◽  
Andreas Jeromin
Keyword(s):  
Boundary Layer ◽  
Wind Turbine ◽  
Meteorological Data ◽  
Turbine Blades ◽  
Stable Stratification ◽  
Offshore Wind ◽  
Wind Turbine Blades ◽  
Shape Factors ◽  
Neutral Boundary Layer ◽  
The Stability

To gain insight into the differences between onshore and offshore atmospheric turbulence, 2 pressure fluctuations were measured for offshore wind under different environmental conditions. 3 A durable piezo-electric sensor was used to sample turbulent pressure data at 50 kHz. Offshore 4 measurements were performed at 100 m height on Germany’s FINO3 offshore platform in the 5 German Bight together with additional meteorological data provided by Deutscher Wetterdienst 6 (DWD). The statistical evaluation revealed that the stability state in the atmospheric boundary has a 7 large impact on turbulent fluctuations. Therefore, we used higher statistical properties (described 8 by so-called shape factors) to the stability state. Data was classified to be either within the unstable, 9 neutral or stable stratification. We found that in case of stable stratification, the shape factor is 10 mostly close to zero, indicating that a thermally stable environment produces closer-to Gaussian 11 distributions. Non-Gaussian distributions were found in unstable and neutral boundary layer states 12 and an occurrence probability was estimated. Possible impact on laminar-turbulent transition on the 13 blade is discussed with application of so-called laminar aerofoils on wind turbine blades. Use of a 14 cut-off frequency to separate load and aerodynamic turbulence is proposed.

scholarly journals Measurements of High-Frequency Atmospheric Turbulence and Its Impact on the Boundary Layer of Wind Turbine Blades

2018 ◽  
Vol 8 (9) ◽  
pp. 1417 ◽  
Author(s):  
Alois Schaffarczyk ◽  
Andreas Jeromin
Keyword(s):  
Boundary Layer ◽  
Wind Turbine ◽  
Atmospheric Turbulence ◽  
Turbine Blades ◽  
Stable Stratification ◽  
Offshore Wind ◽  
Wind Turbine Blades ◽  
Gaussian Distributions ◽  
Neutral Boundary Layer ◽  
The Stability

To gain insight into the differences between onshore and offshore atmospheric turbulence, pressure fluctuations were measured for offshore wind under different environmental conditions. A durable piezo-electric sensor was used to sample turbulent pressure data at 50 kHz. Offshore measurements were performed at a height of 100 m on Germany’s FINO3 offshore platform in the German Bight together with additional meteorological data provided by Deutscher Wetterdienst (DWD). The statistical evaluation revealed that the stability state in the atmospheric boundary does not seem to depend on simple properties like the Reynolds number, wind speed, wind direction, or turbulence level. Therefore, we used higher statistical properties (described by so-called shape factors) to relate them to the stability state. Data was classified to be either within an unstable, neutral, or stable stratification. We found that, in case of stable stratification, the shape factor was mostly close to zero, indicating that a thermally stable environment produces closer-to Gaussian distributions. Non-Gaussian distributions were found in unstable and neutral boundary layer states, and an occurrence probability was estimated. Possible impacts on the laminar-turbulent transition on the blade are discussed with the application of so-called laminar airfoils on wind turbine blades.

scholarly journals Rain Erosion Maps for Wind Turbines Based on Geographical Locations: A Case Study in Ireland and Britain

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
K. Pugh ◽  
M. M. Stack
Keyword(s):  
Wind Turbine ◽  
Western Europe ◽  
Meteorological Data ◽  
Turbine Blades ◽  
Weather Conditions ◽  
Annual Rainfall ◽  
Wind Turbine Blades ◽  
Weather Patterns ◽  
The Uk

AbstractErosion rates of wind turbine blades are not constant, and they depend on many external factors including meteorological differences relating to global weather patterns. In order to track the degradation of the turbine blades, it is important to analyse the distribution and change in weather conditions across the country. This case study addresses rainfall in Western Europe using the UK and Ireland data to create a relationship between the erosion rate of wind turbine blades and rainfall for both countries. In order to match the appropriate erosion data to the meteorological data, 2 months of the annual rainfall were chosen, and the differences were analysed. The month of highest rain, January and month of least rain, May were selected for the study. The two variables were then combined with other data including hailstorm events and locations of wind turbine farms to create a general overview of erosion with relation to wind turbine blades.

Flapwise Bending Vibration Analysis of Rotating Tapered Rayleigh Beams for the Application of Offshore Wind Turbine Blades

2021 ◽  
Vol 35 (4) ◽  
pp. 544-553
Author(s):  
Yan-fei Chen ◽  
Zhi-peng Zang ◽  
Shao-hua Dong ◽  
Chuan Ao ◽  
Hao Liu ◽  
...  
Keyword(s):  
Wind Turbine ◽  
Vibration Analysis ◽  
Turbine Blades ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Wind Turbine Blades ◽  
Bending Vibration

scholarly journals Damage tolerance and structural monitoring for wind turbine blades

2015 ◽  
Vol 373 (2035) ◽  
pp. 20140077 ◽  
Author(s):  
M. McGugan ◽  
G. Pereira ◽  
B. F. Sørensen ◽  
H. Toftegaard ◽  
K. Branner
Keyword(s):  
Wind Turbine ◽  
Damage Tolerance ◽  
Turbine Blades ◽  
Turbine Rotor ◽  
Rotor Blades ◽  
Offshore Wind ◽  
Tolerance Index ◽  
Wind Turbine Blades ◽  
Efficient Operation ◽  
Reliable Design

The paper proposes a methodology for reliable design and maintenance of wind turbine rotor blades using a condition monitoring approach and a damage tolerance index coupling the material and structure. By improving the understanding of material properties that control damage propagation it will be possible to combine damage tolerant structural design, monitoring systems, inspection techniques and modelling to manage the life cycle of the structures. This will allow an efficient operation of the wind turbine in terms of load alleviation, limited maintenance and repair leading to a more effective exploitation of offshore wind.

RESEARCH OF THE ROTATIONAL EFFECTS ON THE BOUNDARY LAYER OF WIND TURBINE BLADES

2009 ◽  
Vol 23 (03) ◽  
pp. 505-508 ◽  
Author(s):  
RUI YANG ◽  
REN-NIAN LI ◽  
WEI HAN ◽  
DE-SHUN LI
Keyword(s):  
Boundary Layer ◽  
Wind Turbine ◽  
Turbine Blades ◽  
Aerodynamic Coefficients ◽  
Wind Turbine Blades ◽  
Pressure Distributions ◽  
Rotating Blade ◽  
Show Evidence ◽  
Layer Flow ◽  
Nrel Phase Vi

The flow field past the rotating blade of a horizontal axial wind turbine has been modeled with a full 3–D steady–RANS approach. Flow computations have been performed using the commercial finite–volume solver Fluent. The NREL phase VI wind turbine blade sections from the 3–D rotating geometry were chosen and the corresponding 2–D flow computations have been carried out for comparison with different angles of attack and in stalled conditions. The simulation results are analyzed. The main features of the boundary layer flow are described, for both the rotating blade and the corresponding 2–D profiles. Computed pressure distributions and aerodynamic coefficients show evidence of less lift losses after separation in the 3–D rotating case, mostly for the inward sections of the blade and the highest angles of attack, which is in agreement with the literature.

scholarly journals CFD–RANS analysis of the rotational effects on the boundary layer of wind turbine blades

2007 ◽  
Vol 75 ◽  
pp. 012031 ◽  
Author(s):  
Carlo E Carcangiu ◽  
Jens N Sørensen ◽  
Francesco Cambuli ◽  
Natalino Mandas
Keyword(s):  
Boundary Layer ◽  
Wind Turbine ◽  
Turbine Blades ◽  
Wind Turbine Blades ◽  
Rans Analysis

Smart Loads Management for Damaged Offshore Wind Turbine Blades

2015 ◽  
Vol 39 (4) ◽  
pp. 419-436 ◽  
Author(s):  
Phillip W. Richards ◽  
D. Todd Griffth ◽  
Dewey H. Hodges
Keyword(s):  
Wind Turbine ◽  
Turbine Blades ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Wind Turbine Blades
Sign in / Sign up

Export Citation Format

Share Document