Abstract
ABSTRACTHigh wind speeds associated with Low-Level Jet (LLJ) make wind resources more favorable for wind energy production. However, the aerodynamic loads of large-scale horizontal axis wind turbine (HAWT) rotor under different LLJ inflow conditions have not been thoroughly studied. To gain insight into the aerodynamic loads of rotor under LLJ inflow conditions with different LLJ intensities, a method to establish an engineering LLJ inflow model was proposed according to the plane wall jet theory and Von Karman spectra model with user-defined scaling. The parameters in the engineering LLJ inflow model were determined by comparing the wind speed distribution obtained from the GP_LLJ spectral model, which was summarized from field measurements in the real atmosphere. The LLJ fluctuating wind fields with different intensities generated by the engineering LLJ inflow model were used as the inflow conditions of Fatigue, Aerodynamics, Structures, and Turbulence (FAST) open source code to calculate and analyze the aerodynamic loads of the HAWT. It was found that the engineering LLJ inflow model can be used to establish the LLJ inflow condition of HAWT. When the LLJ height is located at the hub height and LLJ intensity increases from 8 to 16 m/s, the RMS rotor unbalanced aerodynamic load coefficients, including ones of lateral force, longitudinal force, tilt moment and yaw moment are increased by 2.2, 2.13, 1.02 and 0.95 times, respectively.
Highlights
Low-Level Jets (LLJs), which are defined as relative maxima in the profiles of the wind speed within the atmospheric boundary layer, have been widely concerned due to their close connection with the climate formation process and wind energy utilization
The results indicated that the LLJ impose mechanical loads and fatigue cycles over the wind turbines (Gutierrez et al, 2016)
The GP_LLJ spectral model (Jonkman & Buhl, 2006) based on the Lamar Low-Level Jet Program (LLLJP) (Kelley et al, 2004) that developed by the National Renewable Energy Laboratory (NREL), U.S Department of Energy (DOE) and General Electric Wind Energy was developed to describe the LLJ structural characteristics by the researchers of the NREL
Summary
Low-Level Jets (LLJs), which are defined as relative maxima in the profiles of the wind speed within the atmospheric boundary layer, have been widely concerned due to their close connection with the climate formation process and wind energy utilization. To elucidate the influence of LLJ intensity on aerodynamic loads of HWAT rotor, a method to establish an engineering LLJ inflow model was proposed according to the theory of plane wall jet and Von Karman spectra model with user-defined scaling. The rotor aerodynamic loads were studied under LLJ fluctuating wind fields with different intensities generated by the engineering LLJ inflow model. Results of this study can provide a method to establish the LLJ inflow conditions of HAWTs and clarify the aerodynamic loads of the large-scale HAWTs under LLJ inflow conditions with different LLJ intensities
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
