Abstract:
A blade for a wind turbine defines an airfoil with a leading edge section and a trailing edge section, notably a flat-back trailing edge. A rounded connecting section interconnects a pressure side section of the airfoil and the trailing edge section. The rounded connecting section attaches to the pressure side section at a transition point, in which the pressure side section's tangent does not coincide with the rounded connecting section's tangent, so that the outer surface of the airfoil has a sharp corner at said transition point. The truncated radius, i.e. geometrical discontinuity, thus formed at the transition between the pressure side section and the trailing edge section increases the aerodynamically effective surface of the pressure side and enables forced and hence controlled flow separation without compromising ease of manufacture and structural stability of a fibre-reinforced structure making up a shell of the blade.
Abstract:
A wind turbine blade having an elongated blade body extending along a longitudinal axis and having an upper skin and a lower skin, the lower skin spaced from the upper skin in a thickness direction of the blade body, the upper skin and/or lower skin having a laminated layer, the laminated layer having an outer layer wherein the outer layer forms part of the upper and/or lower skin respectively, an inner layer spaced from the outer layer in the thickness direction; and an intermediate layer sandwiched between the outer layer and inner layer, the intermediate layer having a plurality of heat transfer paths within the intermediate layer for transferring heat.
Abstract:
The invention relates to turbulence sensor for wind turbine blades. The sensor is configured to promote turbulence of air flowing over the blade at a location of the sensor which comprises a detector configured to detect air turbulence. Since the sensor promotes turbulence compared to adjacent locations of a wind turbine blade the sensors can be used to predict that the blade is close to a stall conditions.
Abstract:
A wind turbine having at least one trailing edge control surface on at least one rotor blade is operated in a first mode, in which a rotor blade angle of attack and a trailing edge control surface deflection are set according to one or more wind turbine control parameters. The turbine is selectively operated in a second, noise reduced, mode, in which for a given set of wind turbine control parameters, the trailing edge control surface deflection is increased towards the pressure side and the rotor blade angle of attack is decreased with respect to the first mode. In the second mode, for a given set of control parameters, the loading on the blade is on average closer to a hub than in the first operating mode.
Abstract:
The invention relates to a wind turbine blade (5) comprising at least one flow modifying device (51) adapted to modify the airflow so as to provide a control force (CF), located downwind of a shear centre (SC) of the blade (5), so as for the blade (5) to twist to provide a change (dAF) of a lift force (AF1, AF2) on the blade (5), the lift force (AF1, AF2) including the control force (CF), the change (dAF) being positive in a direction opposite to the direction of the control force (CF).
Abstract:
The rotor blades of a wind turbine each have a plurality of fibre-optic pressure variation sensors which can detect the onset of a stall condition. The output of the stall condition sensors is input to a stall count circuit which increases a stall count signal each time a stall indication is received. The stall count signal is decayed exponentially over time and the current signal is summed with the decayed signal from a previous sampling period to form a value from which a stall margin is determined. An λ:θ curve of tip speed to wind speed ratio λ against pitch angle reference θ is then determined from the stall margin.
Abstract:
A wind turbine blade having an elongated blade body extending along a longitudinal axis and having an upper skin and a lower skin, the lower skin spaced from the upper skin in a thickness direction of the blade body, the upper skin and/or lower skin having a laminated layer, the laminated layer having an outer layer wherein the outer layer forms part of the upper and/or lower skin respectively, an inner layer spaced from the outer layer in the thickness direction; and an intermediate layer sandwiched between the outer layer and inner layer, the intermediate layer having a plurality of openings extending through the intermediate layer from the inner layer to the outer layer; and a plurality of corresponding heat conductor elements extending through the plurality of openings from the inner layer to the outer layer for transferring heat from the inner layer to the outer layer.
Abstract:
The invention relates to a wind turbine comprising a rotor with at least one blade, characterized in that a flap (2) is arranged to at least partly extend along at least a part of a threshold thickness section (A) of the blade in which the airfoil thickness is at least 36%, the flap being arranged so that a slot is provided between the threshold thickness section and the flap, the chord of the flap being at least 15% of the chord of the threshold thickness section.
Abstract:
Wind turbine blade (1) comprising a blade body (2) and lift-regulating means (3, 7) adapted for movement in relation to the blade body (2) by at least one actuation means (4) controlled by an actuation controller (5), wherein the actuation controller (5) controls a setting of the lift-regulating means (3, 7) based on an input from a sensor (6), wherein the sensor (6) is a force sensor adapted for sensing a force from a wind flow acting on the lift-regulating means (3, 7), whereby a wind turbine blade with fast-responding lift-regulating means is provided.