Presentation is loading. Please wait.

Presentation is loading. Please wait.

ASME 2002, Reno, 14-17 January VIBRATIONS OF A THREE-BLADED WIND TURBINE ROTOR DUE TO CLASSICAL FLUTTER Morten Hartvig Hansen Wind Energy Department Risø.

Similar presentations


Presentation on theme: "ASME 2002, Reno, 14-17 January VIBRATIONS OF A THREE-BLADED WIND TURBINE ROTOR DUE TO CLASSICAL FLUTTER Morten Hartvig Hansen Wind Energy Department Risø."— Presentation transcript:

1 ASME 2002, Reno, January VIBRATIONS OF A THREE-BLADED WIND TURBINE ROTOR DUE TO CLASSICAL FLUTTER Morten Hartvig Hansen Wind Energy Department Risø National Laboratory

2 ASME 2002, Reno, January Outline Motivation Stall-induced vibrations versus classical flutter Turbine Model Description and structural analysis Blade Flutter Stability limits Effect of flapwise discretization Turbine Flutter Stability limits Comparison with blade flutter Visualization of flutter mode

3 ASME 2002, Reno, January Motivation Post-design solution to stall-induced vibrations Softening of stall Primary design solution to classical flutter Center of mass towards the leading edge High torsional stiffness Improved turbine design??

4 ASME 2002, Reno, January Turbine model 3N blade DOFs and 7 tower/nacelle DOFs Center of mass and elastic axis at mid-chord Blade Element Momentum theory Quasi-steady aerodynamics, and no turbulence or shear

5 ASME 2002, Reno, January Campbell diagrams Basic model configuration: 1 flap (1.14 Hz), 1 lag (1.46 Hz), and 1 torsion (16.0 Hz) mode. low range high range

6 ASME 2002, Reno, January Operation conditions Variable speed and pitch turbine

7 ASME 2002, Reno, January Aerodynamic conditions in steady state = Attached flow conditions

8 ASME 2002, Reno, January Single blade flutter Aeroelastic damping of torsion mode in basic model configuration: 1 flap, 1 lag, and 1 torsion mode.

9 ASME 2002, Reno, January Single blade flutter Pitching and flapping motion at 75 % radius, wind speed 20 m/s, and torsion frequency 8.5 Hz.

10 ASME 2002, Reno, January Stability limits for blade flutter Effect of the discretization of flapwise blade motion

11 ASME 2002, Reno, January Damping of blade torsion on turbine Basic model configuration with original torsion frequency of 16 Hz

12 ASME 2002, Reno, January Comparison of flutter limits The critical torsion frequency is higher for turbine flutter!

13 ASME 2002, Reno, January Flutter motion Pitching and flapping motion at 75 % radius, wind speed 20 m/s, and torsion frequency 8.5 Hz.

14 ASME 2002, Reno, January Flutter whirling amplitudes

15 ASME 2002, Reno, January Conclusion Structural dynamics of turbines is important Affects the risk of flutter (and stall-induced vibrations) Flutter analysis must include these effects Blade-only analysis is not conservative Flutter may become a problem for large turbines Future Inclusion of unsteady aerodynamics Optimization of turbine dynamics Complete stability and optimization tool


Download ppt "ASME 2002, Reno, 14-17 January VIBRATIONS OF A THREE-BLADED WIND TURBINE ROTOR DUE TO CLASSICAL FLUTTER Morten Hartvig Hansen Wind Energy Department Risø."

Similar presentations


Ads by Google