Such a servo motor 66 can be mounted at or near the pivot point of the wing 20, 22 to effect the change of the AoA. This motor mounting point would be at the one quarter chord length point in the embodiment shown in FIG. For example, the words “upwardly”, “downwardly”, “rightwardly” and “leftwardly” will refer to the directions shown in the drawings to which reference is made. For medium and large size wind turbines, to reduce the centrifugal force in rotational motion, blades are usually long and slender particularly near the tips even though they are made of light composite materials.
- θwind the direction of the wind
- Caso Clínico
- Dolor o molestia en el pecho, tales como el estrechamiento del tórax
- Prueba de folato
- Calzado inadecuado,
- HS is the significant wave height, measured in meters
During operation as a rotor 10, in the first and fourth quarters of a rotational cycle (when β is between about 0 and about π/2 and between about 3π/2 and about 2π), the effective AoA of the first wing 20 and the effective AoA of the second wing 22 are set to be positive, such that the aerodynamic lift creates a clockwise torque and rotational motion. A controller is also provided to direct the adjustment of the angle of attack of the first wing and the second wing in a coordinated manner while the fluid flow-powered generator is in use. Other known of methods for measuring wind speed and direction can also be used. 1 and 3 is aligned with the central axis member 14 perpendicular to the incoming wind direction (V∞) via the rotating table 24, with the leading edge 40 of each wing 20, 22 facing the incoming wind direction (V∞).
When in operation as a rotor 10, rotational motion of the central axis member 14 is directly generated. In a rotary fluid flow-powered generator, the rotational motion of the frame is not constrained, and the angle of attack of the first and second wings is adjusted to allow the frame to spin through the full rotation. A controller 62 calculates the desired effective AoA (α1) of the first wing 20 and the second wing 22 to maintain the maximum effective AoA before stall, and therefore to achieve the largest lift magnitude in all phases of operation of the wind-powered generator 10. Feedback closed-loop control is used by the controller 62 to direct adjustment of the first wing 20 and adjustment of the second wing 22 to maintain the desired effective AoA.
To maintain a constant efficiency, the frequency of oscillation can be proportionally increased with the wind speed. The first wing 20 is mounted between the first pair of transverse arms 16 and the second wing 22 is mounted between the second pair of transverse arms 18, with the first and second wings 20, 22 in a generally vertical orientation. The dynamics of a wind oscillator 10 and a wind rotor 10, 70 are described by the same equation of motion in which the aerodynamic forces on a set of first wing 20 and second wing 22 act as the driving forces for the generation of electricity. The efficiency of power generation of the wind-powered generator 10, 70 described herein is also high, particularly at low wind speeds.
The alternating rotational movement of the central axis member 14 is translated to linear reciprocating motion, which is then converted to rotational motion for the generation of electricity. In addition to the horizontal axis rotor 10, as shown in FIG. Mejorar dolor de espalda . In functioning as a horizontal-axis rotor 10, as shown in FIGS. The configuration of the presently disclosed wind-powered generators 10, 70 also allows for easier access to the gearbox 32 and generator 30 than in conventional designs. Typically, the reduced frequency based on the frequency of changing the AoA, wind speed and the wing chord is less than 0.2, and therefore the quasi-steady assumption is a reasonable first-order approximation. 15 illustrates the effective AoA, induced AoA change and geometric AoA as a function of the rotational angle for a wind rotor 10 at a wind speed of 6 m/s. Unlike the decaying trend of efficiency in an oscillator at a fixed oscillating frequency, the efficiency in a wind rotor slightly increases with the wind speed since the rotational frequency increases accordingly, as shown in FIG.