HRP20100151A2 - Swing wing like the drive for windgenerator - Google Patents

Abstract

The swinging wing as a wind turbine drive belongs to a group of alternative energy sources. Due to the nature of its translational movement, which it accomplishes with the help of parallelograms (2), it has an optimum angled angle a throughout the entire length of its wings. As there is no circumferential velocity, geometric vitoperation of the wings is avoided, and thus the expansion of the buoyancy force Fu into tangential and axial ones is avoided. In this way, the buoyancy force Fu is fully utilized in the torque, which increases the usability of the entire system. The utilization is also increasing, because the swinging wing can act as a wind turbine propulsion even during stormy winds, namely the resisting forces that could cause the structure to break only for the wing according to: FO = 1/2 p ko, v2 A. Performing and later Maintaining the swinging wing has the advantage that the speed multiplier with the generator and other accessories is mounted on the ground.

Description

Field of invention

This invention belongs to the field of alternative sources of energy, namely wind energy. The kinetic energy of the wind is converted into mechanical work with the help of aerodynamic profiles, in other words the invention belongs to the field of aerodynamics.

Technical problem

A series of technical problems are solved with the completely new concept of the propulsion-buoyancy principle with translational movement. There are no longer rotating wing blades, there is no peripheral speed, and thus the aerodynamic efficiency increases due to the more favorable effect of forces on the airfoil. The usability further increases because the resistance forces, which would break the structure in case of strong winds, are calculated only for the resistance of the swinging wing. In the case of wind turbines, the entire surface described by the wing blades is counted, that's why they stop in strong winds, because the resisting force on the high load-bearing column has a strong breaking moment at the root of the column. In other words, the oscillating wing can work even in stormy winds. Since there is no supporting column and since the generator with the rotation speed multiplier and other systems is located inside the base, technical problems with construction, assembly and servicing are greatly simplified.

Security technical problems have been reduced to the lowest level. There is no risk of breaking the wing blade or the entire windmill, without rotating wing blades there are no more unwanted vibrations, dynamic imbalance, resonance with the supporting column...

In addition to technical problems, environmental problems are also solved. The oscillation period is two to three times longer than one revolution of the windmill. With a diameter of the wind wheel of 40 m, the tip of the wing blade has a speed of 60 ms-1, or 216 km/h, which causes a constant noise, and when passing by the supporting column, an intermittent noise. Due to the low swing speed, there is no danger for the birds.

State of the art

As a result of the rotation of the wing blades, we have a circumferential velocity, which is proportional to the radius and angular velocity, u=rω, as the radius increases, the local circumferential velocity also increases. Because of this, the angle of the air flow to the wing blades changes, which requires a geometric fanning of the same. However, despite this, the efficiency decreases, if we analyze the vector diagram of the forces acting on the segment of the wing blade, we will see that only part of the lift force Fu is converted into tangential T, Fig. 2a.

The tangential component creates useful torque. This segment of the wing blade was taken at approximately 60% distance from the center of the rotor axis. Towards the tips of the wing blades, the situation is even more unfavorable, the tangential component T decreases, and the axial component S increases.

In Figure 2a, the aerodynamic forces are:

Fu - lift force calculated according to Fu = 1/2 ρ kuw2 A, where:

ρ = 1.25 kg/m3

ku = lift coefficient

w = current speed m/s

A = wing blade area in mz

The tangential component is calculated according to T = R cos β

R = resultant of lift and drag force on the aerodynamic profile.

From the relation for calculating the power of wind turbines Pe = 0.29d2v3η1 where:

d = diameter of wing blades

v = wind speed

η1 = useful wing profile, it is visible how the entire wind wheel affects the air flow through the rotor.

Due to the utilization of a part of the kinetic energy of the wind, the wind speed decreases and it is this deceleration of the mass of air that passes through the wind wheel that creates the force F, which, with the height of the supporting column, gives the breaking moment of the same. In Fig. 3. a diagram of wind speed and the spread of currents after passing through the wind wheel according to Bemuli's law is shown. As it is a question of high load-bearing columns and - as there are moments of inertia that prevent the rapid action of safety protections, whether it is a matter of converting the wing blades to a "knife" or rotating the rotor from the direction of the wind, it is necessary to go to higher standards in the protection systems. This is especially the case with a gale, which is a gusty wind that creates a turbulent atmosphere, which is very dangerous because it can cause the separation of currents from the upper surface of the airfoil, this leads to a breakdown of lift and "flutter" of the wing blade if it is not dynamically stable and eventually to breakage the same. Wing blade breakage is particularly dangerous if it occurs at maximum rotation speeds and when it closes an angle of 45° with the support pole, calculations show for a 40 m diameter wind turbine that the blade could fall up to 165 m from the pole. That's why parallel protection systems, mainly self-braking, are installed, which work automatically.

In addition to structural requirements, today's wind turbines also require top-notch technology for assembly and service operations that are not at all behind the construction ones. A special crane is required to mount one wind turbine.

Presentation of the essence of the invention

With the new concept of harnessing wind energy via translationally oscillating wing fig.1. we come to the primary goal of the invention, greater usability. With the translational movement of the wings left-right and vice versa, there are no more circumferential speeds, and thus the entire lift force Fu creates a useful torque, fig.2b.

Usability increases because the oscillating wing can work even in stormy winds. The resistance force that would cause the structure to break is now calculated only for the wing according to F0=1/2ρkov2A where:

co=coefficient of resistance of the profile, at the maximum angles of attack, is about 0.12.

The resisting force now acts on the much shorter arm h, and not as before on the top of the bearing column.

The secondary goal of the invention was to avoid the support column, to place the speed multiplier with the generator and other systems as close to the ground as possible. This greatly reduces manufacturing, assembly and servicing costs. The further essence of the invention is the simplification of safety protection measures, because there are no rotating wing blades, which in case of breakage endanger the middle, the swinging wing in the worst case can fall next to the base.

Additional goals are of an ecological nature. In the natural environment, everything sways in the wind, from grass to huge trees. Fields of wind turbines with swaying wings would look like a forest of tall trees.

Brief description of the drawing

Sl. 1. draft and side view of swinging wing;

Sl. 2a. diagram of aerodynamic forces on the wing blade profile;

Sl. 2b. diagram of aerodynamic forces on the swing wing profile;

Sl. 3. diagram of wind speed and currents through the turbine rotor;

Sl. 4. diagram of the dependence of the lift coefficient on the inclination angle a for the NACA 0015 profile;

A detailed description of at least one way of realizing the invention

The oscillating wing as the driving part of the wind generator according to this invention comprises a wing (1) with a symmetrical NACA 0015 profile, because when oscillating left and right, it is necessary to generate buoyant force in both directions. Control mechanism (2) with lever parallelogram is responsible for translational movement of the wings. The second control mechanism (3), which is located inside the rotating platform (4), changes the inclined angle of the wing (1) synchronously with the oscillation.

The rotating platform (4) together with the wing (1) is placed in the wind with the help of the stabilizer (6). The buoyant force Fu is converted from linear to circular movement via levers and eccentrics on the first speed multiplier (7). In order to stabilize the circular motion and as the oscillating wing passes through the points of zero lift, a flywheel (8) is needed at the ends of the oscillating when the lean angle changes.

The swinging wing (1) is weight-balanced with weights (11), which contributes to dynamic balance, and at the same time simplifies the assembly and lifting of the wing into the working position. The wing (1) swings left-right and vice versa up to +/- 45°, and the control mechanism (3) towards the ends of the swing reduces the tilt angle a from the maximum +/- 20° to zero and when the wing (1) goes in the opposite direction , mechanism (3) increases it again to the maximum fig.2b.

In Fig. 4. diagram on the dependence of the lift coefficient on the angle of inclination for the NACA 0015 profile, it can be seen that the maximum lift is achieved at 16° of the angle of inclination, but that profiles of 15% thickness belong to the group of thicker profiles, and that its maximum curvature is at 30% from the beginning wing chords, such a profile does not have a sudden breakdown of lift. That is why this profile can withstand a maximum angle of +/- 20° without the air currents completely detaching, or the lift breaking down.

The energy from the flywheel (8) is transmitted to the speed multiplier (9), which coordinates the rotation speed with the generator (10).

Method of application of the invention

Like previous wind turbines, the oscillating wing for driving wind generators can contribute a lot to "clean" energy.

The oscillating wing can especially be used in confined spaces, for example, on yachts and other boats, where the direction stabilizer would be replaced by sensors.

Claims (1)

1. The oscillating wing as the drive of the wind generator and the wind turbine work on the same principle, the lift force Fu is realized on the aerodynamic profile by converting the kinetic energy of the wind, however, the wind turbine is not able to convert the entire component of the lift force Fu into a useful torque, due to the peripheral speed; on the other hand, the oscillating wing as the drive of the wind generator "indicated by" with the help of the parallelogram lever (2) has the character of translational movement left-right without peripheral speed, and thus the entire propulsive force Fu is converted into a useful torque, and the control mechanism (3) sets the wing (1) to the optimal lean angle.