Abstract:
A blade, for a rotor of a wind turbine has a profiled contour in a radial direction is divided into a root region with a substantially circular or elliptical profile closest to the hub and an airfoil region with a lift generating profile furthest away from the hub. A transition region between the root region and the airfoil region has a profile gradually changing in the radial direction from the circular or elliptical profile of the root region to the lift generating profile of the airfoil region, and the airfoil region comprises at least a first longitudinal segment extending at least 20% of a longitudinal extent of the airfoil region. The first longitudinal segment has a first base part with a cross-sectional profile such that, when impacted by an incident airflow at an angle of attack of 0 degrees has a lift coefficient, which is 0 or less.
Abstract:
A blade for a rotor of a wind turbine is divided into a root region closest to the hub and an airfoil region with a lift generating profile furthest away from the hub. A transition region has a profile gradually changing in the radial direction from the circular or elliptical profile of the root region to the lift generating profile of the airfoil region, and includes at least a first longitudinal segment extending along at least 20% of a longitudinal extent of the airfoil region. A base part has an inherent non-ideal twist, such as no twist, or a reduced twist compared to a target blade twist, so that an axial induction factor of the first base part at a design point deviates from a target axial induction factor. A number of flow altering devices are arranged so as to adjust the aerodynamic properties of the first longitudinal segment.
Abstract:
The present invention relates to a design concept by which the power, loads and/or stability of a wind turbine may be controlled by typically fast variation of the geometry of the blades using active geometry control (e.g. smart materials or by embedded mechanical actuators), or using passive geometry control (e.g. changes arising from loading and/or deformation of the blade) or by a combination of the two methods. The invention relates in particular to a wind turbine blade, a wind turbine and a method of controlling a wind turbine.
Abstract:
A blade for a rotor of a wind turbine is manufactured with a root region with a substantially circular or elliptical profile closest to the hub, an airfoil region with a lift generating profile furthest away from the hub and a transition region having a profile gradually changing the root region to the airfoil region. A first blade design is used for the first base part on a first longitudinal section of an airfoil region of a second blade, so that an induction factor of the first base part on the second blade deviates from a target induction factor. The first longitudinal section of the second blade is provided with flow altering devices so as to adjust the aerodynamic properties of the first longitudinal segment to substantially meet the target induction factor at the design point on the second blade.
Abstract:
A blade for a rotor of a wind turbine has a root region with a substantially circular or elliptical profile closest to the hub and an airfoil region with a lift generating profile furthest away from the hub. A transition region has a base part with an inner dimension that varies linearly in the radial direction of the blade in such a way that an induction factor of the first base part without flow altering devices at a rotor design point deviates from a target induction factor. The first longitudinal segment is provided with a number of first flow altering devices arranged so as to adjust the aerodynamic properties of the first longitudinal segment to substantially meet the target induction factor at the design point.
Abstract:
A blade for a rotor of a wind turbine has a root region with a substantially circular or elliptical profile closest to the hub and an airfoil region with a lift generating profile furthest away from the hub. A transition region has a base part with an inner dimension that varies linearly in the radial direction of the blade in such a way that an induction factor of the first base part without flow altering devices at a rotor design point deviates from a target induction factor. The first longitudinal segment is provided with a number of first flow altering devices arranged so as to adjust the aerodynamic properties of the first longitudinal segment to substantially meet the target induction factor at the design point.
Abstract:
A blade, for a rotor of a wind turbine has a profiled contour in a radial direction is divided into a root region with a substantially circular or elliptical profile closest to the hub and an airfoil region with a lift generating profile furthest away from the hub. A transition region between the root region and the airfoil region has a profile gradually changing in the radial direction from the circular or elliptical profile of the root region to the lift generating profile of the airfoil region, and the airfoil region comprises at least a first longitudinal segment extending at least 20% of a longitudinal extent of the airfoil region. The first longitudinal segment has a first base part with a cross-sectional profile such that, when impacted by an incident airflow at an angle of attack of 0 degrees has a lift coefficient, which is 0 or less.
Abstract:
A blade for a rotor of a wind turbine having a substantially horizontal rotor shaft, the rotor comprising a hub, from which the blade extends substantially in a radial direction when mounted to the hub. The blade comprises a main blade part having a profiled contour comprising a pressure side and a suction side as well as a leading edge and a trailing edge with a chord extending between the leading edge and the trailing edge. The profiled contour generates a lift when being impacted by an incident airflow. The profiled contour is divided in the radial direction into a root region with a substantially circular or elliptical profile closest to the hub, the substantially circular or elliptical profile having a diameter, an airfoil region with a lift generating profile furthest away from the hub, and a transition region between the root region and the airfoil region. The profile of the transition region gradually changes in the radial direction from the circular or elliptical profile of the root region to the lift generating profile of the airfoil region. The blade further comprises a first auxiliary airfoil having a first pressure side and a first suction side as well as a first chord extending between a first leading edge and a first trailing edge. The first chord has a length that is 75% or less of the diameter of the substantially circular or elliptical profile in the root region and the first auxiliary airfoil is arranged so that it extends in the radial direction along at least a part of the root region of the main blade part with a distance there between.
Abstract:
A wind turbine blade with a plurality of flow guiding device parts attached to a profiled contour on a pressure side of the blade is described. The longitudinally extending flow guiding device parts are grouped together to form a first flow guiding device group in the transition region of the blade.
Abstract:
A wind turbine blade with a flow guiding device attached to a profiled contour on a pressure side of the blade is described. The flow guiding device extends along at least a longitudinal part of a transition region of the blade and is arranged so as to generate a separation of airflow along at least a central longitudinal portion of the flow guiding device from the pressure side of the blade at a point between the flow guiding device and a trailing edge of the blade, when the blade is impacted by an incident airflow. The flow guiding device is arranged at a relative chordal position, seen from the leading edge of the blade, lying in an interval between 40% and 92%. The relative height of the flow guiding device is at least 10% of a maximum thickness of the profiled contour.