RU2333382C1 - Magnus effect amplification technique - Google Patents

Abstract

FIELD: electrical energy.

SUBSTANCE: the invention pertains to wind-power engineering and specifically to construction of windmills with a horizontal axis of rotation with use of the Magnus effect. The method of amplifying the Magnus effect is characterised by use of a wind wheel with a horizontal shaft and cowlings, radial blades in form of cylindrical rotors, actuators for rotating rotors and a generator, an electric motor for driving the rotors. Extra profiled planes are installed in the wind wheel in form of blades along each cylindrical rotor. The profiled planes make the rotors immoveable and fix their bottom part directly to the front part of the rotating cowling of the wind wheel and/or not less than 8 cuts are made on the perimeter of the cylindrical rotor along its length In the counter current flow direction, a front blade for splitting the stream, blade for compressing the stream in the direction of acceleration of the stream and a reactive blade are installed respectively. An extra blade for slowing down the incident flow can be installed on the side of the braking rotor zone In the stream compressor and/or reactive blade, and/or blade for slowing down incident flow, a special slit is formed. Cuts can be parabolic shaped

EFFECT: increased efficiency of the wind wheel on the Magnus effect by several times.

5 cl, 5 dwg.

Description

Application area

The invention relates to wind energy, and in particular to the construction of wind turbines with a horizontal axis of rotation using the Magnus effect, and is intended to enhance the Magnus effect.

State of the art

Known wind turbines with a horizontal axis of rotation with radial blades in the form of forcibly rotated cylinders (Magnus rotors // Pat. USSR 10198, F03D 7/02, 1927; Pat. US 4366386, F03B 5/00, F30D 7/06, 1982; application of Germany 3246694, F03D 5/00, 1984; A.S. 1677366, F03D 1/02, USSR, 1991, etc.).

The main disadvantages of these wind turbines are quite complex drives for rotating the cylinders, which makes manufacturing more expensive and reduces the reliability of the installation, as well as the impossibility of their practical use in the aquatic environment during and in the portable form.

A device is known according to patent GB 248471 dated 05/05/1924. The disadvantage of this device should be considered the lack of indications of the type of rotor drive from the motor, which is made by low-efficiency worm gear transmission of torque through a hollow bulky frame to a bevel gear. This principle of rotor drive leads to a backward reaction of the wind wheel, which will tend for some time, especially at the initial stage of promotion, to follow the main shaft of the installation. The same force will be constantly present as a harmful, taking away part of the promotion energy for oneself. However, the device does not indicate the principles of torque selection.

A device is known according to patent DE 3800070 A1 dated 07/13/1989. The disadvantage of this type of installation, working on the principle of spinning the rotors from the built-in spiral accelerator, the flow of which is released through the exhaust windows at the ends of the cylinders, should be considered the fact that the power of the installation of this type will be quite low, because the promotion of rotors from wind energy is ineffective.

A device is known according to the patent UA 63018 C2 from 01/15/2004. The disadvantage is that for the promotion of industrial-type wind wheel rotors, when it is necessary to achieve high torque, this device is not effective, because firstly, the bulkiness of such structures automatically increases with an increase in the size of a wind turbine, and secondly, harmful windage occurs, which is unacceptable in squally winds. Such installations in hurricane winds become a huge sail, and their design may not withstand the air pressure. In addition, a significant complication of the design will lead to an increase in material consumption and the price of the entire installation. The more details in the design, the greater its complexity and probability of failure. Installations of this type are suitable only as low-power wind generators.

A device is known according to patent DE 3501807 A1 dated 07.24.1986. The disadvantage of this type of device is that the very method of spinning the rotors in terms of performance is in great doubt, because There are some contradictions in the use of the Magnus effect in this design.

A device is known according to patent AU 573400. A disadvantage of this type of device should be considered that the rotor spin drive drives the installation itself. The installation has no power elements that prevent vibration of the rotors. Some options for the promotion of rotors are presented, but a specific scheme is not proposed.

A close analogue should include the device according to patent US 4366386 from 12.28.1982. The disadvantage of this type of device is the maximum complexity of the design using a huge number of differentials and gear systems. In the inventive device, this moment is circumvented by one simple solution: the electric rotor drive is installed directly on the gearbox of the rotors themselves, transmitting torque as quickly as possible and without loss of energy.

The disadvantages of all the aforementioned analogs include the fact that none of the authors of these patents expressed the main theoretical essence of the Magnus effect, namely, that a very inconspicuous detail is hidden in its principle: the relationship (according to Bernoulli's law) between static and dynamic pressures rotor surfaces. Using the dynamic pressure (pv ^2/2) in the claimed method occurs change control "shell" - air pressure on the rotor, i.e. the static structure.

Technical result

In the claimed invention, an increase in the Magnus effect is achieved.

Achievement of a result

This technical result in a method of enhancing the Magnus effect, characterized by the use of a wind wheel with a horizontal shaft and a cowl, radial blades in the form of cylindrical rotors, drives for rotating rotors and an electric generator, an electric motor for driving rotors, is achieved by installing additional profiled planes in the form of a blade along each cylindrical rotor, which with respect to the rotors themselves are made stationary and fastened from the root side directly to the front h The parts of the rotating fairing of the wind wheel and / or along the circumference of the circumference of the cylindrical rotor along its length make recesses in an amount of at least 8.

The end parts of the blades are fixed and fixed in the landing lodges between two plates, on which, in the direction of the oncoming flow, a blade of the front flow divider, a blade of the flow seal on the side of flow acceleration and a jet blade are installed.

Additionally, from the side of the braking zone of the rotor, a free flow braking blade is installed.

In the seal of the flow and / or jet blade and / or the brakes of the inlet of the incoming flow form special gaps so that it is possible to suck in an additional portion of air or to prevent the earlier occurrence of a zone of stall air flow.

The recesses have a parabolic shape.

Brief Description of the Drawings

Figure 1 shows the General structural device of the wind wheel (front view).

Figure 2 shows the constructive device and the location and shape of the fixed blades (side view), as well as the principle of the free flow on the structure of the wind wheel, where 1 is the main shaft of the wind wheel of the installation, 2 is the rotor shaft, 3 is the fairing of the wind turbine, 4 is the cylinder rotor, 5 - a plate for fixing fixed blades and a flow divider, 6 - a front flow divider blade, 7 - a flow compactor blade, 8 - a reactive blade, 9 - an incoming flow braking blade, 10 - an aerodynamic ring or a ring consisting of parts of its about a circle connected between sections by duralumin tubes with built-in antivibrators (aerodynamic antivibrator), 12 - slots in the blades.

Figure 3 shows a conventional trickle explaining the principle of the distribution of air velocity and pressure depending on the inlet and outlet sections of the jet.

Figure 4 shows the principle of formation of air flows during operation of the installation only with a method of enhancing the Magnus effect due to the notches on the cylinders.

Figure 5 shows possible embodiments of the recesses in a cylindrical rotor.

SUMMARY OF THE INVENTION

The main element of a wind turbine operating on the basis of the Magnus effect is a cylindrical rotor (4) of complex shape (see Figure 1, 2).

Each cylinder (4) of the rotor is mounted on the axis of rotation (2), coming from the gearbox with bevel gears. The fastening of the rotors to the axes of rotation, as well as a large proportion of component parts and mechanisms, is not the subject of protection of the present invention and is not shown in the drawings.

The torque created by the untwisted cylinder gives the torque an order of magnitude greater than the blade of a conventional wind turbine propeller. Moreover, a change in the shape of the surface of a rotating cylinder gives a several-fold increase in the efficiency of the wind wheel on the Magnus effect.

This is explained by the physical laws of the equations of continuity of the air stream stream (see Figure 3) (constant air flow) - the aerodynamics equation arising from the basic laws of physics (conservation of mass and energy) and establishing the relationship between the density, speed and cross-sectional area of the air stream stream .

When considering it, the condition is accepted that the air under study does not have the compressibility property (see Figure 3).

In a trickle of variable section, a second volume of air flows over section I over a certain period of time. This volume is equal to the product of the air velocity and the cross section F.

The second mass air flow rate m is equal to the product of the second air flow rate by the density of the stream air stream ρ. According to the law of energy conservation, the mass of the air stream m1 flowing through section I (F1) is equal to the mass m2 of this stream flowing through section F2, provided that the air flow is steady: that is, m ₁ = m ₂ = const, m ₁ · F ₁ · V ₁ = m ₂ · F ₂ · V ₂ = const.

This equation is called the continuity equation of a stream of air stream of a stream.

Since we are considering an incompressible air flow, where the density of the jet ρ ₁ , section F ₁ , is equal to the density of the stream ρ ₂ , section F ₂ , that is, ρ ₁ = ρ ₂ = const, the equation can be written in the following form: F ₁ · V ₁ = F ₂ · V ₂ = const.

Now we turn to the principle of flow around a cylinder. If we draw a cylinder in two projections: when we see it in plan “in length” and from the end, we get the following mathematical picture.

According to the foregoing (see Figs. 3, 4) it can be seen that the power of wind turbines based on the Magnus effect depends not only on the diameter of the wind wheel, but also depends on the diameter of the cylinder itself.

The dynamics of changes in static pressure and pressure head shows that the static pressure on the half-rotor, with the acceleration of the speed flow, falling about 20 times, changes its value along a complex curve. It is commensurate with the tendency to change the curvature forming the cylinder. In this case, the dynamic pressure changes approximately 400 times. Such a picture of the pressure change has the difficulty of calculating also because the angle of the velocity stream meeting with the laminar layer changes all the time. In this case, the circular vector of the laminar flow, touching along the normal to the point under consideration, constantly changes the angle with respect to the velocity flow vector, to the top of the dynamics acceleration. It decreases to the top, and then, having crossed it, increases. But here the trend of the high-speed flow does not change according to the law, as before reaching its maximum value (see Figure 4, from the zone p1-p2, to the zone p3-p4 and further, to the zone p8-p9-p10).

In the aerodynamics of a conventional propeller, it has been proved that the high-speed pressure gets its maximum value at a distance from the propeller by at least 1/2 of its diameter. And only then does the reverse flow reaction occur. Traction appears. On the reverse side of the half-rotor, the magnitude of the change in statics and dynamics is as follows. The incoming flow is inhibited by a rotating laminar flow.

It is impossible to theoretically calculate the braking value and the zone itself (see Figure 3, zone p1-p7-p6-p12-p11-p10). Blowing in the wind tunnel is required.

However, based on the theory of aerodynamics, we can confidently assume that the magnitude of the static and dynamic pressure on the rotor will be significantly higher when the surface shape of the rotor changes from smooth to multifaceted, and especially when the shape of the faces is non-linear.

As a conclusion, the total torque created by the rotor-cylinder is affected not only by the speed of the incoming flow and the span of the wind wheel, but also by the diameter of a single cylinder. Equally important is its longitudinal shape and sectional shape. An important factor is also the speed of rotation of the cylinder.

With the non-linear shape of the faces, the rotor speed must be not less than the speed of the incoming wind flow, because a flow inhibition effect appears due to swirling of the boundary layer. The rotor speed can be automatically adjusted by reading the wind speed sensor.

The achievement of the claimed technical result is due to the fact that apply additional profiled planes along each cylinder of the rotor, which are fixed relative to the rotors themselves.

The combination of the rotating cylinder (4) with the fixed blades (6, 7, 8, 9), which are attached from the root side directly to the front of the rotating fairing (3) of the wind turbine, is shown in Figs. 1 and 2.

The end parts of these blades (6, 7, 8, 9) are attached and fixed in the landing lodges between the two plates (5). On the plates (5) in the direction of oncoming flow, the following can be fixed: front flow divider (6), flow seal on the side of flow acceleration (7), which serves to expand the coverage area of the incoming flow, its ordering and acceleration to very significant values, and behind the flow seal, a jet blade (8) can be installed, which serves to create additional rotation force of the entire wind wheel. Additionally, from the side of the braking zone of the rotor, a free-wheel braking blade (9) can be installed, which serves to enhance braking of the free-flow, expanding the turbulence zone itself, and to create additional rotation force of the wind wheel.

All blades (7, 8, 9), with the exception of the front divider (6), can be made with special slots (12) (see Figure 2), which either contribute to the absorption of an additional portion of air or to prevent an earlier occurrence of the stall zone flow.

Each of the blades (6, 7, 8, 9) can be used both individually and all blades simultaneously. In the latter case, the amplification of the Magnus effect becomes maximum. In some cases, the blades can be attached directly to the aerodynamic ring, while the design of the wind wheel is simplified, and the butt parts of the blades can be attached directly to the rotating part of the fairing.

Thus, the flow pattern of a rotating rotor finds a complete view of the maximum possible use of the kinetic energy of the incoming flow. The limits of airflow use towards small values are expanding sharply, i.e. for small wind zones, where the wind speed does not exceed 2-3 m / s, installations using the claimed invention become most effective in comparison with classical type wind turbines.

And at a wind speed of about 10 m / s or more for the spinning of rotors, the self-energy consumption decreases sharply, and the efficiency of the installation increases.

In addition, using the claimed invention, it becomes possible to create small-sized wind turbines of high power.

Strengthening the Magnus effect can additionally be achieved by changing the shape of the rotating cylinder of the rotor.

The rotor length is in square proportion to the diameter of the entire wind wheel. Nevertheless, it is possible to obtain another dependent quantity that affects the total power, which is inherent only in the active method of processing air flow: the dependence of power not only on the magnitude of the entire wind wheel, but also on the diameter of a single cylinder, as well as on its shape. This is explained as follows (see Figure 4). When the cylinder rotates, viscous air “sticks” to the surface of the cylinder, and adjacent layers of air circulate along with the rotating surface of the cylinder. The farther away the incoming air mass is from the cylinder, the less dependent it is on the rotating cylinder. In this case, the flow begins to acquire an ordered shape around the cylinder, and its velocity characteristics increase, i.e. the speed of the incident flow is added to the speed of the air particles directly adjacent to the surface of the cylinder. The result is a boundary layer of air (see Figure 4).

The air velocity at the bottom of the cylinder is less (here, V _{2 of the} incident flow is subtracted when it is decelerated by the boundary layer of the cylinder), which means that the pressure rises.

On the reverse side, the flow velocity and the cylinder add up, which means that the speed increases, which leads to a decrease in pressure. Due to the pressure difference, the resulting pressure force on the cylinder arises, which will move towards lower pressure, i.e. (in our case) up.

Based on the foregoing, if recesses are formed along the circumference of the cylinder along the length of the cylinder, then the effect of enhancing the rotation of the rotor will be ensured, the effect of both acceleration and deceleration of the flow around the rotor-cylinder will be provided, and the change in the diameter value is interconnected with the explanation of the parameters according to the law mass conservation in a conventional trickle.

Thus, the claimed result of enhancing the Magnus effect can also be realized by using a cylinder containing along the entire circumference of the circumference along its entire length of the recess, as shown in Figure 4.

The dimensions and shape of the recesses are not critical, but it is preferable that the recesses have a parabolic shape. The number of located recesses around the perimeter of the cylinder circumference depends on the value of the speed of the oncoming wind flow and can vary from 8 or more, as shown in Fig. 5.

The magnitude of the total torque when using the Magnus effect in combination with fixed blades can be expressed as follows:

∑Мкр = Мкр.m. + Мкрл.,

where Mkr.m. - the magnitude of the torque created purely by the Magnus effect,

Micr.l. - the magnitude of the torque generated by the blades.

In turn, the force created only by the area of the jet blade is determined by the formula:

где

Where

- скоростной напор, S - площадь лопасти, из которой ясно, что основная составляющая этой силы - это (в нашем случае) величина скоростного напора, где скорости потока могут достигать сотен м/с, что выше штормовых значений.With _y is the aerodynamic coefficient;

is the velocity head, S is the area of the blade, from which it is clear that the main component of this force is (in our case) the magnitude of the velocity head, where the flow velocity can reach hundreds of m / s, which is higher than storm values.

The magnitude of the force created by the blade of the compressive flow is determined experimentally, because the magnitude of the velocity head has a complex character of formation and behavior between the blade itself and the rotating cylinder. In addition, the blade itself is in rotation mode, which means that the angle of attack of the incoming flow is complex.

Principle of operation

The principle of operation of a power plant, based on the use of the Magnus effect, is as follows.

When the motor is turned on (not shown in the drawings), its rotation is transmitted to the main bevel gear of the rotor cylinder (4) or to the driven gears of the rotor shaft drives (2). The drive gear drives the driven gears with the shafts (2) of the rotors. When spinning the rotors, the Magnus effect occurs.

Fundamentally, the effect itself consists in the fact that when a stream flows around a rotating cylinder (4), a pressure difference arises (if you look at the diagram) above and below the cylinder.

This is due to the fact that the incident flow, coinciding with the direction of rotation of the cylinder, is superimposed on the laminar layer of air on the cylinder itself. In this case, the flow rate and the cylinder rotation speed add up, that is, the total flow velocity of the cylinder increases. The reverse is the opposite.

As a result of this, an upward force arises, i.e. in the area of less pressure. This, in turn, drives the wind wheel.

The torque created by the untwisted cylinder gives the torque an order of magnitude greater than the blade of a conventional screw. Moreover, a change in the shape of the surface of a rotating cylinder gives a several-fold increase in the efficiency of the wind wheel on the Magnus effect.

Claims (5)

1. A method of enhancing the Magnus effect, characterized by the use of a wind wheel with a horizontal shaft and a cowl, radial blades in the form of cylindrical rotors, drives for rotating rotors and an electric generator, rotor drive electric motor, characterized in that additional profiled planes are installed in the form of a blade along each cylindrical rotor, which, in relation to the rotors themselves, are made stationary and fixed from the root side directly to the front of the rotating fairing of the windbreaker A groove and / or around the circumference of the circumference of the cylindrical rotor along the length of its grooves make notches in an amount of at least 8. 2. The method of enhancing the Magnus effect according to claim 1, characterized in that the end parts of the blades are fixed and fixed in the seat lodges between two plates, on which, in the direction of the oncoming flow, respectively, the blade of the front flow divider, the blade of the flow seal from the acceleration side are installed flow and jet blade. 3. A method of enhancing the Magnus effect according to any one of claims 1 or 2, characterized in that, in addition, from the side of the braking zone of the rotor, a free flow braking blade is installed. 4. The method of enhancing the Magnus effect according to any one of claims 1 or 2, characterized in that in the flow seal and / or reactive blade and / or the inlet flow brake vanes form special slots so that it is possible to suck in an additional portion of air or prevent the earlier occurrence of a zone of stall air flow. 5. The method of enhancing the Magnus effect according to claim 1, characterized in that the recesses are made in a parabolic shape.

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