Evaluation of horizontal-axis wind-turbine-blade loads using unsteady aerodynamics

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1989

OSTI ID:5639589

Hartin, J R

Most existing analyses of the blade loads on horizontal axis wind turbines are conducted using linear steady-state aerodynamics, but evaluation of loads resulting from wind turbulence or gusts may not be adequate using these techniques. This study develops single-parameter approximations for both the shed wake and trailing wake components of the unsteady aerodynamics and incorporates them into a code that evaluates mean and cyclic blade loading. The effect on loads due to the deterministic effects of wind shear and tower interference and the stochastic effects of wind turbulence are examined. The aeroelastic equations including degrees of freedom for blade flexing and axial tower motion are solved in the time domain using turbulent wind input. Verification of the single-parameter models is by comparison to general analytic solutions and test data available in the literature. The model for shed wake is compared to exact solutions for translating airfoils and to two-dimensional approximations for rotary-wing effects. Two trailing wake models are evaluated using results from wind turbine tests and helicopter analysis. Comparison of loads predictions is made to Howden 330/26 Wind Turbine data showing good agreement for cyclic and mean loads. Results show that the largest contribution from unsteady aerodynamics is an increase in mean loads due to the induced velocity lag caused by the trailing wake.

• Research Organization: Oregon State Univ., Corvallis, OR (United States)
• OSTI ID: 5639589
• Country of Publication: United States
• Language: English

Related Subjects

17 WIND ENERGY
170602* -- Wind Energy Engineering-- Turbine Design & Operation
AERODYNAMICS
COMPARATIVE EVALUATIONS
DEGREES OF FREEDOM
DYNAMIC LOADS
EVALUATION
FLUID FLOW
FLUID MECHANICS
HORIZONTAL AXIS TURBINES
MACHINERY
MATHEMATICAL MODELS
MECHANICS
STOCHASTIC PROCESSES
TURBINE BLADES
TURBINES
TURBOMACHINERY
TURBULENCE
UNSTEADY FLOW
WIND LOADS
WIND TURBINES