Abstract: A blade for a wind turbine includes a total backward twist of between approximately 6 degrees and approximately 15 degrees between an outer approximately 1 percent to approximately 10 percent of a rotor radius of the blade; and a total normalized chord change of between approximately one percent and approximately two percent between the outer approximately 1 percent to approximately 10 percent of the rotor radius of the blade.

Abstract: A blade for a wind turbine includes a total backward twist of between approximately 6 degrees and approximately 15 degrees between an outer approximately 1 percent to approximately 10 percent of a rotor radius of the blade.

Abstract: A wind turbine blade instrumentation structure and method is provided for fluid dynamic polymer-based contact sensors measuring ambient pressure based on the resistivity changes across the sensor. The pressure sensors may applied in predetermined patterns to airfoil structures, such as wind turbine blades, without impacting the blade structure and fluid dynamic characteristics. The pressure sensors measure blade performance with high fidelity. The pressure measurements are transmitted to processing to determine blade characteristics and environment including flow separation, stagnation point, angle of attack, lift and drag and wind speed. Further processing of the pressure distribution may identify wind shear, up-flow and yaw error.

Abstract: A blade for a wind turbine includes a total backward twist of between approximately 6 degrees and approximately 15 degrees between an outer approximately 1 percent to 10 percent of a rotor radius of the blade; and an approximate planform distribution within the following ranges r/R c/R(LE) c/R(TE) .96 0.60 to 0.65% ?1.42 to ?1.34% .968 0.54 to 0.59% ?1.31 to ?1.34% .974 0.39 to 0.58% ?1.36 to ?1.22% .9806 0.13 to 0.57% ?1.45 to ?1.06% .9856 ?0.23 to 0.56%?? ?1.56 to ?0.74% .9906 ?0.76 to 0.55%?? ?1.74 to ?0.24% .9956 ?1.44 to 0.54%?? ?1.99 to 0.23%?? 1.00 ?2.17 to 0.54%?? ?2.27 to 0.44%?? where “r/R” is an approximate normalized distance outward from a center of rotation of the blade along a span of the blade; and “c/R(LE)” and “c/R(TE)” are approximate relative positions of a leading (LE) and trailing edge (TE) of a chord “c” expressed as a percentage of a distance outward from the center of rotation at each r/R.

Abstract: A fluid dynamic polymer-based contact sensor measures ambient pressure based on the resistivity changes across the sensor under different ambient pressures. The pressure sensor may applied to airfoil structures such as wind turbine blades without impacting the blade structure and fluid dynamic characteristics. The sensor may also be applied to fluid measurements. The pressure measurements are used to measure blade performance with high fidelity. The pressure measurements are transmitted to processing to determine blade characteristics and environment including flow separation, stagnation point, angle of attack, lift and drag and wind speed. Further processing of the pressure distribution may identify wind shear, up-flow and yaw error.

Abstract: A wind turbine blade instrumentation structure and method is provided for fluid dynamic polymer-based contact sensors measuring ambient pressure based on the resistivity changes across the sensor. The pressure sensors may applied in predetermined patterns to airfoil structures, such as wind turbine blades, without impacting the blade structure and fluid dynamic characteristics. The pressure sensors measure blade performance with high fidelity. The pressure measurements are transmitted to processing to determine blade characteristics and environment including flow separation, stagnation point, angle of attack, lift and drag and wind speed. Further processing of the pressure distribution may identify wind shear, up-flow and yaw error.

Abstract: A fluid dynamic polymer-based contact sensor measures ambient pressure based on the resistivity changes across the sensor under different ambient pressures. The pressure sensor may applied to airfoil structures such as wind turbine blades without impacting the blade structure and fluid dynamic characteristics. The sensor may also be applied to fluid measurements. The pressure measurements are used to measure blade performance with high fidelity. The pressure measurements are transmitted to processing to determine blade characteristics and environment including flow separation, stagnation point, angle of attack, lift and drag and wind speed. Further processing of the pressure distribution may identify wind shear, up-flow and yaw error.

Abstract: A blade for a wind turbine includes a total backward twist of between approximately 6 degrees and approximately 15 degrees between an outer approximately 1 percent to approximately 10 percent of a rotor radius of the blade.

Abstract: A blade for a wind turbine includes a total backward twist of between approximately 6 degrees and approximately 15 degrees between an outer approximately 1 percent to 10 percent of a rotor radius of the blade; and an approximate planform distribution within the following ranges r/R c/R(LE) c/R(TE) .96 0.60 to 0.65% ?1.42 to ?1.34% .968 0.54 to 0.59% ?1.31 to ?1.34% .974 0.39 to 0.58% ?1.36 to ?1.22% .9806 0.13 to 0.57% ?1.45 to ?1.06% .9856 ?0.23 to 0.56%?? ?1.56 to ?0.74% .9906 ?0.76 to 0.55%?? ?1.74 to ?0.24% .9956 ?1.44 to 0.54%?? ?1.99 to 0.23%?? 1.00 ?2.17 to 0.54%?? ?2.27 to 0.44%?? where “r/R” is an approximate normalized distance outward from a center of rotation of the blade along a span of the blade; and “c/R(LE)” and “c/R(TE)” are approximate relative positions of a leading (LE) and trailing edge (TE) of a chord “c” expressed as a percentage of a distance outward from the center of rotation at each r/R.

Abstract: A blade for a wind turbine includes a total backward twist of between approximately 6 degrees and approximately 15 degrees between an outer approximately 1 percent to approximately 10 percent of a rotor radius of the blade; and a total normalized chord change of between approximately one percent and approximately two percent between the outer approximately 1 percent to approximately 10 percent of the rotor radius of the blade.

Abstract: A multi-section blade for a wind turbine comprising a hub extender connected to a hub of the wind turbine is provided. The blade includes at least one pitchable outboard section. The hub extender can have a pitch bearing located near the interface between the hub and hub extender, or the hub extender and outboard blade section. The hub extender can be configured to pitch or not pitch with the outboard blade sections. An aerodynamic fairing is configured to mount over the hub extender and is configured to not pitch with the outboard blade sections.

Abstract: A wind turbine includes a tower supporting a drive train with a rotor, at least one hollow blade extending radially from the rotor; a drain hole arranged in a tip portion of the blade; a baffle, arranged inside the blade and inboard of the drain hole, for impeding a flow of particulate matter to the drain hole; a flexible drain conduit arranged inside the blade for connecting to the drain hole; and a non-flexible drain conduit arranged inside the blade for connecting to the flexible drain conduit, the non-flexible conduit having a plurality of openings for receiving fluid from inside the blade.