ALBUQUERQUE, N.M. — Wind gusts often provide problems for wind turbines. They cause extraneous blade motion, resulting in additional blade fatigue that reduces the life of the blade.
Don Lobitz, retired but consulting for Sandia’s Wind Energy Technology Department, has created a computer model of a blade that twists when a gust of wind hits it, alleviating the gust load and significantly reducing fatigue. Called aeroelastic tailoring, the response to a wind gust is reduced due to a decrease in the angle of attack.
Under contract to Sandia, researchers at Stanford University have produced an aeroelastically tailored D-spar, a long structure made of carbon graphite fibers embedded in an epoxy resin having a D-shaped cross section. Subsequent laboratory testing indicated that significant amounts of twist occurred when bending loads were applied. Next summer a blade with aeroelastic tailoring will be one of those tested at the National Wind Technology Center and the Department of Agriculture’s research station in Bushland, Texas.
“We’ll first test blades without aeroelastic tailoring and then ones that have it,” says Lobitz. “Testing devices placed on the blades will measure their motion, from which comparisons will be made. We expect to see less fatigue on the blades with the aeroelastic tailoring.”
Return to Sandia researchers seek ways to lower the cost of wind energy
See: New Mexico Wind Energy Center to open this fall
Sandia technical contact: Tom Ashwill, tdashwi@sandia.gov, (505) 845-8457