An Experimental and Computational Approach to Iced Wind Turbine Aerodynamics
Open Access
- Author:
- Blasco, Peter Michael
- Graduate Program:
- Aerospace Engineering
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- January 05, 2015
- Committee Members:
- Sven Schmitz, Thesis Advisor/Co-Advisor
- Keywords:
- wind
turbine
aerodynamics
icing
iced
wind-tunnel
AERTS
experiments
utility-scale
rotor
blade
XTurb - Abstract:
- This thesis presents an analysis of power loss of a representative 1.5 MW wind turbine for variable icing conditions. Power losses are estimated using aerodynamic data obtained in a combination of two experimental methods. Atmospheric icing conditions varying in temperature, droplet size, and liquid water content are generated in an icing facility to simulate a 45-minute icing event on a representative wind turbine airfoil section. The ice shapes are then molded for preservation and subsequent wind-tunnel testing. Lift and drag measurements are made and used to estimate the total power production of the iced wind turbine using a blade-element momentum theory prediction code. Detailed measurements of ice profiles show that aerodynamic penalties are mainly a function of surface roughness due to icing. A 16% loss of airfoil lift at operational angle of attack is observed for freezing-fog conditions. Drag increases at a lift coefficient of 0.5 are observed to be 190% at temperatures near 0°C, 145% near -10° C, and 80% near -20°C. An analysis of the wind turbine aerodynamic loads due to atmospheric icing yields power losses ranging from 16% to 26% near an average wind speed of 8 m/s. An exception to these results exists for a single super-large droplet icing case in which lift decrease and drag increase are more severe at 25% and 219%, respectively. The analysis gives insight to potential control strategies for wind turbine operators attempting to minimize revenue loss in cold-climate operations.