Sailing wind generator. Sailing wind turbine: design analysis and examples of use Alternative wind energy CIS

Enough interesting design chosen by the author of this wind generator. This is a sailing wind generator with a truss-type mast and a power of up to 4 kW per hour.

Materials and parts used in the construction of this wind generator:
1) parts from the bridge and rims
2) profile pipe
3) winch
4) engine direct current on brushes and magnets produced in 1971

Let's take a closer look at the design of this wind generator.

The author dug a hole under the base of the mast and filled it with concrete. Mortgages are made in concrete for screwing the mast onto bolts. Thanks to this thorough approach to fastening, you will be confident that the mast is reliable in any wind.

Then the author began to manufacture the rotating axis of the wind generator. The axle was made from parts from the bridge and wheel rims. The total weight of the structure was about 150 kilograms.

To lift and install parts on an already installed wind generator mast, the author used a simple winch.
Thus, the rotary structure was first raised, and then the generator itself.

At the same time, he was working on the design of a wind wheel.

Then the sails were put on the frame of the wind wheel.

After which the installation of the wind wheel on the generator mast began. The lift was carried out using the same winch. After which the wind wheel was installed in its place and secured with bolts.

In this form, the wind generator had already started working and was producing necessary energy for charging batteries.

In this picture you can see the electrical circuit of the ballast regulator.

A charging and power take-off controller was also made.

And the wind wheel itself had stronger sails.

The author built this wind generator as an experiment. As a result, this experimental sample performed excellently. At the time of completion of these upgrades, the wind generator was used in conjunction with a 12 volt 155A battery. The design was supplemented with a standard 12\220 volt inverter, thanks to which the author could use a TV, laptop and other household electrical appliances from wind generator energy. In the future, the author plans to make a converter, a Tesla coil, to transmit energy wirelessly, that is, to continue experimenting.

The activities of both individual people and all of today's humanity are practically impossible without electricity. Unfortunately, the rapidly increasing consumption of oil and gas, coal and peat is leading to a decrease in the reserves of these resources on the planet. What can be done while earthlings still have all this? According to the conclusions of experts, it is the development of energy complexes that can solve the problems of global economic and financial crises. Therefore, the search and use of fuel-free energy sources is becoming the most urgent.

Renewable, ecological, green

Perhaps it is not worth reminding that everything new is well forgotten old. People learned to use the power of river flow and wind speed to generate mechanical energy a very long time ago. The sun heats our water and moves our cars, powers spaceships. Wheels installed in the beds of streams and small rivers supplied water to fields back in the Middle Ages. One could provide flour to several surrounding villages.

At the moment we are interested in a simple question: how to provide your home with cheap light and heat, how to make a windmill with your own hands? 5 kW power or a little less, the main thing is that you can supply your home with current to operate electrical appliances.

Interestingly, in the world there is a classification of buildings according to the level of resource efficiency:

• conventional, built before 1980-1995;
• with low and ultra-low energy consumption - up to 45-90 kWh per 1 kW/m;
• passive and non-volatile, receiving current from renewable sources (for example, by installing a rotary wind generator (5 kW) with your own hands or a system of solar panels, you can solve this problem);
• energy-efficient buildings that generate more electricity than they need earn money by passing it on to other consumers through the grid.

It turns out that your own home mini-stations, installed on roofs and in courtyards, can eventually become a kind of competition to large power suppliers. Yes and governments different countries strongly encourage the creation and active use

How to determine the profitability of your own power plant

Researchers have proven that the reserve capacity of winds is much greater than all the accumulated fuel reserves of centuries. Among the methods of obtaining energy from renewable sources, windmills have a special place, since their production is simpler than the creation of solar panels. In fact, you can assemble a 5 kW wind generator with your own hands, having the necessary components, including magnets, copper wire, plywood and metal for the blades.

Experts say that a structure not only of the correct shape, but also built in the right place, can be productive and, accordingly, profitable. This means that it is necessary to take into account the presence, persistence and even speed air flow in each individual case and even in a specific region. If the area periodically experiences calm, calm and windless days, installing a mast with a generator will not bring any benefit.

Before you start making a windmill with your own hands (5 kW), you need to think about its model and type. You should not expect a large energy output from a weak design. And vice versa, when you only need to power a couple of light bulbs in your dacha, there is no point in building a huge windmill with your own hands. 5 kW is a power sufficient to provide electricity to almost the entire lighting system and household appliances. If there is a constant wind, there will be light.

How to make a wind generator with your own hands: sequence of actions

At the location chosen for the high mast, the windmill itself with the generator attached to it is strengthened. The generated energy is supplied through wires to the desired room. It is believed that the higher the mast structure, larger diameter wind wheel and the stronger the air flow, the higher the efficiency of the entire device. In reality, everything is not quite like that:

• for example, a strong hurricane can easily break the blades;
• some models can be installed on the roof of a regular house;
• a properly selected turbine starts easily and works perfectly even in very low wind speeds.

Main types of wind turbines

Designs with a horizontal axis of rotation of the rotor are considered classic. They usually have 2-3 blades and are installed at a high height from the ground. Greatest efficiency This installation appears at a constant direction and its speed is 10 m/s. Significant disadvantage This blade design is a failure of rotation of the blades with frequently changing, gusty conditions. This leads to either unproductive operation or destruction of the entire installation. To start such a generator after stopping, a forced initial rotation of the blades is necessary. In addition, when the blades actively rotate, they produce specific sounds that are unpleasant to the human ear.

A vertical wind generator (“Volchok” 5 kW or another) has a different rotor placement. H-shaped or barrel-shaped turbines capture wind from any direction. These structures are smaller in size, start even at the weakest air flows (at 1.5-3 m/s), do not require high masts, and can be used even in urban environments. In addition, self-assembled windmills (5 kW - this is real) reach their rated power at wind speeds of 3-4 m/s.

Sails are not on ships, but on land

One of the popular trends in wind energy now is the creation of a horizontal generator with soft blades. The main difference is both the material of manufacture and the shape itself: self-created windmills (5 kW, sail type) have 4-6 triangular fabric blades. Moreover, unlike traditional structures, their cross-section increases in the direction from the center to the periphery. This feature allows you not only to “catch” weak winds, but also to avoid losses during hurricane air flow.

The advantages of sailboats include the following indicators:

• high power at slow rotation;
• independent orientation and adjustment to any wind;
• high weathervane and low inertia;
• no need to force the wheel to spin;
• completely silent rotation even at high speeds;
• absence of vibrations and sound disturbances;
• relative cheapness of construction.

DIY windmills

The 5 kW of required electricity can be obtained in several ways:

• build a simple rotor structure;
• assemble a complex of several sailing wheels arranged in series on the same axis;
• use an axle design with neodymium magnets.

It is important to remember that the power of a wind wheel is proportional to the cubic value of the wind speed multiplied by the swept area of ​​the turbine. So, how to make a 5 kW wind generator? Instructions below.

You can use a car hub and brake discs as a basis. 32 magnets (25 by 8 mm) are placed parallel in a circle on the future rotor disks (the moving part of the generator), 16 pieces per disk, and the pluses must alternate with the minuses. Opposing magnets must have different pole values. After marking and placement, everything on the circle is filled with epoxy.

Coils of copper wire are placed on the stator. Their number should be less than the number of magnets, that is, 12. First, all the wires are taken out and connected to each other in a star or triangle, then they are also filled with epoxy glue. It is recommended to insert pieces of plasticine inside the coils before pouring. After the resin has hardened and been removed, there will be holes left that are needed for ventilation and cooling of the stator.

How does it all work

The rotor disks, rotating relative to the stator, form a magnetic field, and an electric current arises in the coils. And the windmill, connected through a pulley system, is needed in order to move these parts of the working structure. How to make a wind generator with your own hands? Some people start building their own power station by assembling a generator. Others - from the creation of a rotating blade part.

The shaft from the windmill is engaged by a sliding connection with one of the rotor disks. The lower, second disk with magnets is placed on a strong bearing. The stator is located in the middle. All parts are attached to the plywood circle using long bolts and secured with nuts. Between all the “pancakes”, minimum gaps must be left for free rotation of the rotor disks. The result is a 3-phase generator.

"Barrel"

All that remains is to make windmills. You can make a 5 kW rotating structure with your own hands from 3 circles of plywood and a sheet of the thinnest and lightest duralumin. Metal rectangular wings are attached to the plywood with bolts and angles. First, guide grooves in the shape of a wave are hollowed out in each plane of the circle, into which the sheets are inserted. The resulting double-decker rotor has 4 wavy blades attached to each other at right angles. That is, between each two plywood pancakes fastened to the hubs there are 2 duralumin blades curved in the shape of a wave.

This structure is mounted in the center on a steel pin, which will transmit torque to the generator. Self-made windmills (5 kW) of this design weigh approximately 16-18 kg with a height of 160-170 cm and a base diameter of 80-90 cm.

Things to consider

A “barrel” windmill can even be installed on the roof of a building, although a tower 3-4 meters high is sufficient. However, it is imperative to protect the generator housing from natural precipitation. It is also recommended to install a battery energy storage device.

To obtain alternating current from direct 3-phase current, a converter must also be included in the circuit.

If there are enough windy days in the region, a self-assembled windmill (5 kW) can provide current not only to a TV and light bulbs, but also to a video surveillance system, air conditioning, refrigerator and other electrical equipment.

Dedicated to those who like to discuss KIEV!!!

In domestic aerodynamics, which (sometimes) considers the issues of utilizing the energy of wind flows, the definition was absolutely unreasonably introduced by cunning (that’s right) entrepreneurs - KIEV, the coefficient of wind energy utilization...

This conventional unit (for the flat wind model) is intended to replace the usual efficiency. This “indicator” has been brought into the theory of weak flows by the ears (by analogy and method - the Carnot cycle)

The mathematically correct logic of thermodynamic processes is designed to describe cycles that have a finite (basic) potential of available energy and allows us to determine the following: if you have a heat engine with a power of 100 hp. (with an efficiency of 30%), then in reality only 30 hp are required for useful work. Otherwise: these 30% are the total (100%) available (actually available) power for a given design.

For heat engines, there is no better tool yet.

Otherwise, everything is in practical aerodynamics. To determine the pressure difference (above the wing and under the wing), the amount of motion is used, which is defined as the speed of an object when moving in the air, or (the movement of the air in which the object is located). Consequently, the statement long postulated by Mr. Bernoulli about the dependence of pressure on speed is appropriate here, which means that ultimately the aerodynamic K depends on the pressure difference, which is why the object moves from an area of ​​​​high pressure to an area of ​​​​low pressure. Let's look at atlas (any) of aviation profiles, and pay attention to the speed of flow around the profile at which the pressure difference is maximum. They (the speeds) all, without exception, lie in an area located much HIGHER than the speed of the available everyday wind (3m/sec).

Is it possible in a sane mind to use this method in a small range of winds (flow velocities) without having the results of real blowing? It turns out that it is “possible” - having a flat wind model in service, “theorists” of various ranks prove that bladed wind wheels more fully utilize the energy of small winds. Will the “bladed wheel” even rotate in weak winds? Of course not, just as there is no reason to even think about the use of blades in the CIS as alternative energy sources that utilize weak currents - it is known from practice that in the everyday winds of the CIS, blades do not work, have never worked and will not work. To do this, you need to forcefully rotate the bladed wind wheel, or... wait until The Almighty will send down a strong wind.

Sailboats operate in the entire range of winds.

Designers of (powerful) bladed high-speed wind wheels use the winds quite intelligently. Starting from a speed of 10m/sec. - the butt (wide) part of the blade - moves the blade (like a sail) and in the presence of strong wind, the end profiles (reaching high speeds) use the already high speeds of the flow streams. Quite reasonable. Practical enough. It is at high flow speeds that it is necessary to profile and “twist” (spanwise) the blade. But the available power (air flow energy) coming to the ENTIRE swept area is distributed as follows: the central part of the blade wheel is the engine, and the peripheral part is the energy converter of (already high) wind speeds into torque on the generator shaft.

Double conversion of available energy allows for excellent use of wind energy from 10-12 meters per second (at the same time solving the problem of the speed of generators). The task of a sailing wind wheel is to use all the available power coming to the swept area. Since useful work can only be produced by real forces (generated when a pressure difference is triggered), then “debriefing” must be done with tools familiar (???) for aerostatics than for aerodynamics.

Agree, a telegraph pole standing under the pressure of the wind does work. Work - to DEVIATE the flow coming to it. The energy for this work is supplied by the same wind. If this pillar is cut down, the work will be done EXPLICITLY, the pillar will simply fall. If a sail is stretched on two pillars (and filed), MORE OBVIOUS work will be done. If these pillars are secured to the gearbox SHAFT, work will already be done both by deflecting the air flow and by rotating the shaft. And if you also optimize the design approximately in the same way as a sailing wind wheel (top left) - you will have a wind engine for low winds.

But let’s return to the “analyses” of sailing wind wheels (wandering on the Internet). The mathematical apparatus deserves attention, but the common problem of armchair theorists is the distortion of the physical picture of the process. Indeed, applying to our reasoning the completely correct (2.1.1) - for a fixed plate, and together with the author making a short excursion into the annals of general aerodynamics, already in (2.1.4) we get the exact price - for... firewood.

The fact is that the plate (sail) does not “sort of run away”, i.e., moves (with the flow) along the flow, but is quite actually in the flow and, moreover, deflects the flow beyond the limits of the wind wheel, shifting in a plane perpendicular to the axis rotation of the wind wheel.

Otherwise, unlucky opponents are not too lazy to consider JUST a sail raised on a boat that floats under the influence of the wind in the direction where it blows.
There is clearly expressed love for N.E. Zhukovsky, with his article never accepted in practical aerodynamics
“NEZH type windmills. Article 3."

A sail-type wind wheel actually has a different flow pattern. It's called CONICAL. And the wind wheel as a whole is an annular endless slotted wing, which 95 years ago (at the time of writing the article) did not exist even in a sick imagination. This is now the joint work of the slat with the wing - it is well described for high flow speeds and is understandable. But there is no serious work on ultra-small air flows around the air. And it cannot be because physical quantities such as PRESSURE (in front of the sail, the wind speed dropped and the pressure increased) are also considered in AEROSTATICS. Therefore, nautical terminology is more suitable for me, speaking about the tandem of the staysail and mainsail.

It was the yachtsmen who were the first to appreciate practically what was encrypted by the cabinets - KIEV (I have nothing against the “blade boats” - these machines worked in strong winds and will work (regardless of the Kievs) - for the benefit of people.

The pictures above show a sailing wind wheel and a “propeller”. As you can see, the diameters of the swept areas are equal. But the working bodies differ not only in design. They differ primarily in size, and therefore in working area. In the theory of screws, this is what is stated - the area of ​​​​the working parts. And the ratio of the swept area to the total area of ​​the working parts is called the screw fill factor. To explain it in a very simple way, a “propeller” superimposed on the swept area (mentally) will cover only approximately 10 percent of the entire swept area. A sailing wind wheel under similar conditions will cover almost the ENTIRE swept area. Need comments?

If we consider the picture of the flow around a bladed wind wheel in a specific (any) AZIMUTAL position, we can easily guess that an elementary stream of air passing BETWEEN the blades DOES NOT DO even useless work. The trickle passes through the sieve... With a sailing windwheel, such a number (sorry) will not work - when it arrives at the swept area, an elementary stream of air bumps into (may the experts forgive me) the SAIL. Then everything is simple - it deviates by 90 degrees (if you hold the wheel) and goes (to the periphery) - OUTSIDE the swept area (accelerating). Or, (if you do not hold the wheel) it will deviate to a SMALLER angle, giving energy to the sail, which in its the queue will transfer USEFUL energy to the generator shaft. And if we completely abandon pseudo-scientific analysis and turn our face to practice, then at the test site you often see such a picture, a sailing wind turbine WEU 10.380 (cx) with a wind of 5 m/sec. can't stop a whole group of students from spinning.

A bladed windmill should not be held in such wind. Because it doesn’t spin up at all. But let's return to our opponents. In all sorts of opuses we find that “...if the plate is motionless, then the useful power is zero. If the plate moves at the speed of the wind, then it does not experience pressure and the power is also zero...” - This is, of course, from a great mind. According to the authors, a boat moving in the wind with a raised sail is an unrealistic picture due to its uselessness. Standing at anchor, but with the sail raised, it seems to be a real picture, but the useful power is again equal to zero.

The naive fallacy lies in a complete misunderstanding of the operation of the sail. The fact is that the sail does work both when it moves and when it stands, resisting the wind. In the latter case, ALL the power of the incoming flow turns into the work of the sail to deflect the air flow coming to the swept area. A little is required - to direct this work in a useful direction (unfasten the anchor, or remove the windmill from the brake). A blade installed on a boat instead of a sail will require a very strong wind for these purposes. The same is true for a bladed windmill. But the sail moves the boat (turns the generator) even in low winds. In higher winds it simply produces MORE useful work. To verify this, it is enough to attach a BLADE wind wheel on a boat and a sail wind wheel on another boat, the results of the “experiment” are clear... In the “scientific works” of opponents it is often said “... That is, to achieve maximum KIEV, the speed of the plate should be in three times less than the wind speed." - I leave without comment, since it is clear that the sail reacts to ANY wind and creates the necessary pressure difference. The rest is all from the evil one.

Let's look at a small (top right) “movie”: here is a working sample of a sailing windmill from the Baltics, created specifically to test the capabilities of a sailing windmill. The designer did not purchase drawings, he used the FPP method (floor, finger, ceiling) and intuition, but it is still worth talking about the efficiency of this wind wheel. It is higher than that of a blade (of the same diameter) throughout the entire RANGE of winds, starting from 0.5 m.s. These are the conclusions of a comparative analysis carried out by the craftsman himself. But we are interested in all the delights of a sailing windwheel, which can be seen on this specimen.

It is clear that the wind approaches (to the swept area) from the rear side. The sails are filled with wind in our direction, and slightly at an angle. It is clear to a specialist that the wind, slowing down in front of the wheel and having completed the work, is released through the gap (the rear unsupported edge of the sail). You will agree that through these gaps the already exhausted air leaves (propped up by newly arriving portions of air). Mr. Bernoulli described this more scientifically by postulating the following: when As the flow rate decreases, the pressure increases. As a result, we have increased pressure on the WINDOW side of the wind wheel and VACUUM on the leeward side. It is the activation of the energy of this pressure difference that quantifies the work of the windmill. A bladed wind wheel never dreamed of such a thing... Remember, between the blades the wind freely penetrates onto the opposite side wind wheels - EQUALIZING pressure. Is that bad.

If there is no pressure difference, then what kind of WORK can we talk about at all? Consequently, the main disadvantage of a bladed wind wheel (for small winds): the area outlined by the ends of the blades (swept) is used in an extremely BAD way. This statement can only be refuted by a fool. Argument: if the opposing subject is forced to jump out of a flying plane by offering a choice (instead of a parachute) of a bladed and sailing wind wheel, I bet that the unfortunate person will INTUITIVELY choose a sailing rescue device.

By the way, the serial MD-20 trike with a “spinner” (instead of a standard wing) successfully completed the season in aerial chemical works, showing excellent results - with a wind of 5 m.sec, the take-off length with a standard 100-liter chemical tank was 20(!) meters, the rate of climb was - 4m. Let's return to our movie. Since the windmill was raised above the ground by only 1.5 m. The turbulized ground layer of air (see in which quadrant of the swept area the trailing edge “flaterites”) does not fill the sail. But raised above the ground (checked!) to a height of ONE diameter, the sailing wind wheel comes into full operation. And then - even more interesting: leaving working area the exhaust air (supported from behind) entering the conical bell accelerates again (remember the pressure on the windward side). Let us note something important - the acceleration vector is directed TANGENTIAL to the wind wheel. If we remember the law of conservation of momentum, then half the energy of the kinetic movement of air (we are talking about the second, additional acceleration) goes - again to the same sail wheel. For the slot is nothing more than an ordinary jet nozzle that creates propulsive force.

Increase in the reactive component, at 10m.sec. equal to 40 percent of the total wind energy arriving at the swept area. There is no longer any need to talk about the fact that the starting torque is greater than the working torque (the blades are resting). For particularly militant opponents, I will try to explain the essence of the difference between a sail and a blade on the basis of molecular kinetic theory, without resorting to mathematical apparatus. Experts often write (it’s a shame that they are specialists) citing the following argument: the air flow of a (specific) cross-section contains (specific) energy.

The nature of the origin of the “argument” is simple. Density and velocity (relative to what?) squared are substituted into the well-known formula for kinetic energy. Then all this pleasure is divided by 2. But cutting wood is still better with a saw than with a plane... I recommend turning to the process of DERIVING this formula. In order for a body to move where (fly, run...) it is necessary to give the same amount of energy to the body with which, what moves (flies and jumps) INTERACTS to receive required quantity movements. That is why there is NO fractional line in the potential energy formula. And in the kinetic one - there is.

In the case of a wind wheel (of any type), we work with the full energy of the flow in a way that you and I did not set the air flow (wind) into motion. And back. When considering an airplane wing (helicopter rotor), we must be guided only by KINETIC energy (divide by 2) since WE ourselves force the body (airplane) to move in the air and not vice versa. And you must carry the entire energy supply with you in the form of fuel. Otherwise it simply won't fly.

The fact is that the wind energy generated as a result of gravitational interactions is for ordinary citizens 100 percent (total energy) which the blade must remove from a given (specific) area. Obliged. But - it cannot physically - the dimensions of the blade are not comparable with the cross-sectional area of ​​the jet. Considering the air flow (in the light of MCT), we find that the wind is a directed (ordered) flow of air molecules. Each molecule carries energy (it doesn’t matter who gave it energy - what matters is how to remove it correctly) - and we suddenly put a blade in its path.

Having ricocheted, the molecule gave up part of the energy and, having gone around the obstacle, briefly changed the direction of its own movement (turbulized the flow) and, picked up by its neighbors, carried away further, carrying away its momentum - and therefore energy. Help: any change in the direction of movement of a material point by ANOTHER subject of the physical world is an ENERGY EXCHANGE process. The angle of change in the direction of movement of the molecule determines the AMOUNT of energy transferred to the second body. Stopping a molecule completely by an obstacle means 100 percent transfer of energy to the obstacle.

By slowing down, or rather deflecting a larger number of molecules, we get more energy. Guess which of the two wind wheels in question slows down more molecules? Right. But the “blades” (if they are forced to rotate) will collect (reject) these same molecules. And the higher the angular speed of rotation of the blade, the more molecules they will collide with (remove energy), and at high speeds aerodynamics will also come into play...

The sail wheel does not need to be rotated at all for these purposes. It immediately contacts all molecules coming to the area it sweeps. And receiving energy from many molecules at the same time, it simply spins along with the gearbox shaft.

Are all the benefits of a sail wheel presented here? Of course not. I'll reveal one more “secret”. A sailing wind wheel does not scatter elementary streams of air in different directions, but carefully collects them into its flexible cones (working parts) and releases them through jet slits beyond the swept area. And wherever the stream of air hits - on the edge of the sail or in the center, it will be stopped, redirected, accelerated again (by suitable jets - pressure) and released through the jet gap, giving up all the initial energy and half (now exactly kinetic) of the energy received in acceleration time in the “gutter” of the cone.

This theory is already built on a VOLUMETRIC air model. Where did this second kinetic energy for acceleration come from? Well, if the wind has not been canceled - from the pressure created by elementary streams of air arriving at the swept area.

Well, they are like that - trickles.

Vladimir from Taganrog

Ecology of consumption. Science and technology: We can say that the sail windmill is one of the simplest, but at the same time one of the most inefficient windmills in existence. The KIEV of a sailing wind turbine cannot be higher than 20%, even theoretically.

Humanity has been using sails since time immemorial, for many thousands of years. In general, as long as he can remember. When they had no idea about aerodynamics. But the windmills were already spinning and the boats were already sailing. True, in those days they usually used flat sails. In the Middle Ages, more advanced sails were invented, which immediately led to a sharp leap in the development of navigation, and as a result - the loudest geographical discoveries. But so far the sail continues to serve and will serve people as long as the wind blows.

What a sailing windmill looks like should be clear to you from the photographs. Without going into the jungle of aerodynamics, we can say that the sail windmill is one of the simplest, but at the same time one of the most inefficient windmills in existence. The KIEV of a sailing wind turbine cannot be higher than 20%, even theoretically. This means that you will receive only 1/5 of the power of the wind flow hitting the blades of the sail windmill. For example, if the wind blows at a speed of 5 m/s, and your windmill is 5 meters in diameter, then the power of the wind flow will be approx. 1500 Watt. You can really only remove 300 watts from a windmill (at best). And this is from a five-meter structure!

Fortunately, only low KIEV (coefficientuse of wind energy) the disadvantages of a sailing windmill are limited. Then there are only advantages.

The sail windmill is the slowest windmill. Its speed rarely approaches 2, but is usually in the range from 1 to 1.5. And all because of its monstrous aerodynamics.

On the other hand, the sail windmill is one of the most sensitive windmills. It works from the very bottom of the wind speed range, starting literally from calm, from 1-2 meters per second. And this is an important factor in the conditions of central Russia, where the wind rarely exceeds 3-5 meters per second. Here, where faster windmills mostly flail, a sailing windmill will at least produce something. Although, as you probably know, Russia is not famous for windmills, this is not seaside Holland and the winds do not spoil us. But there were many water mills.

Another advantage of a sailing windmill is the amazing simplicity of its design. The windmill shaft, on bearings, of course, on the shaft is a hub. Attached to the hub are “masts,” usually from 8 to 24. And from the masts come oblique sails made of durable thin material, usually synthetic. The other part of the sail is attached with sheets, which serve both as sail angle regulators and as storm protection. Those. the most primitive sailing equipment, simpler than on the simplest yacht.

It is precisely this simplicity of design that does not allow the sailing windmill to be consigned to the archives of the technical achievements of mankind. For a portable, transportable, camping, emergency option, a sailing windmill is a fairly decent design. When assembled, it is a package no larger than a tent. The sails are furled, the masts are folded. Even a 2-meter sail windmill in a wind of 5 meters/sec will give a faithful 25-40 Watts of energy, which is more than enough to charge batteries and communication and navigation equipment, and even for a simple lighting system using powerful LEDs.

The inherently low power of a sailing windmill suggests the use of a stepper motor of similar power (30-40 Watt) as a generator. It also does not require high speeds; 200-300 per minute is quite enough. Which fits perfectly with the speed of the windmill. After all, with a speed of 1.5, it will produce these 200 revolutions already in a wind of 4-5 meters per second. By using a ready-made stepper motor, you will thereby save yourself from the rather serious hassle of making an electric generator. Since the presence of a gearbox or multiplier is initially assumed, it is easy to coordinate the speed of the sailing windmill and the generator.

If you make an option with rigid (plastic sails), then it will be possible to slightly increase speed, although at the expense of some reduction in mobility. When disassembled, the windmill will take up more space.

Therefore, if your ambitions for harnessing the wind to your cart are limited to a power of a couple of tens of watts for charging small and medium-sized batteries (up to 100 Ah), organizing simple lighting using an inverter up to 220 volts and energy saving lamps, then a sailing windmill is very, very decent option. Although this will not be the most efficient in terms of using wind energy, it will be a very budget-friendly option that will quickly pay for itself. A 2-3 meter windmill will provide you with up to 1 kW of energy per day.

As a camping one, a sailing windmill will be cheaper than the cheapest gasoline electric generator and will pay for itself initially.

Stationary sailing wind turbines are initially built large precisely because of their low KIEV. At least 5-6 meters in diameter, otherwise there is no point. Such a wind turbine will consistently produce up to 2-3 kW of energy per day. And with careful use, they can be turned into 3-5 kW of lighting energy (for example, to illuminate a greenhouse or greenhouse). And when using a heat pump - 5-6 kW of thermal energy, which will allow you to heat a small garden house of 20-30 square meters. meters and seriously save fuel.

Therefore, the sailing windmill, despite its archaic design, remains a way of using wind that still deserves attention. Especially in areas of low winds.

The upper limit of the operating wind speed of a sail windmill is no more than 10-12 meters per second. And then from the most reliable wind turbines. Therefore, when designing a sailing windmill, you should seriously consider storm protection. For example, make “breakable” masts based on the design of the Kulikov antenna, or come up with a device for relaxing sheets to turn sails into flags, or fold masts using guy ropes, etc. published

Russia occupies a dual position with regard to wind energy resources. On the one hand, thanks to the huge total area and due to the abundance of flat areas, there is generally a lot of wind, and it is mostly even. On the other hand, our winds are predominantly low-potential and slow, see Fig. On the third, in sparsely populated areas the winds are violent. Based on this, the task of installing a wind generator on the farm is quite relevant. But in order to decide whether to buy a fairly expensive device or make it yourself, you need to think carefully about which type (and there are a lot of them) to choose for what purpose.

Basic Concepts

1. KIEV – wind energy utilization coefficient. If a mechanistic flat wind model is used for calculations (see below), it is equal to the efficiency of the rotor of a wind power plant (WPU).
2. Efficiency – end-to-end efficiency of the APU, from the oncoming wind to the terminals of the electric generator, or to the amount of water pumped into the tank.
3. Minimum operating wind speed (MRS) is the speed at which the windmill begins to supply current to the load.
4. The maximum permissible wind speed (MAS) is the speed at which energy production stops: the automation either turns off the generator, or puts the rotor in a weather vane, or folds it and hides it, or the rotor itself stops, or the APU is simply destroyed.
5. Starting wind speed (SW) - at this speed, the rotor is able to turn without load, spin up and enter operating mode, after which the generator can be turned on.
6. Negative starting speed (OSS) - this means that the APU (or wind turbine - wind power unit, or WEA, wind power unit) to start at any wind speed requires mandatory spin-up from an external energy source.
7. Starting (initial) torque is the ability of a rotor, forcibly braked in the air flow, to create torque on the shaft.
8. Wind turbine (WM) is part of the APU from the rotor to the shaft of the generator or pump, or other energy consumer.
9. Rotary wind generator - an APU in which wind energy is converted into torque on the power take-off shaft by rotating the rotor in the air flow.
10. The range of rotor operating speeds is the difference between MMF and MRS when operating at rated load.
11. Low-speed windmill - in it linear speed parts of the rotor in the flow does not significantly exceed the wind speed or is lower than it. The dynamic pressure of the flow is directly converted into blade thrust.
12. High-speed windmill - the linear speed of the blades is significantly (up to 20 or more times) higher than the wind speed, and the rotor forms its own air circulation. The cycle of converting flow energy into thrust is complex.

Notes:

1. Low-speed APUs, as a rule, have a KIEV lower than high-speed ones, but have a starting torque sufficient to spin up the generator without disconnecting the load and zero TAC, i.e. Absolutely self-starting and usable in the lightest winds.
2. Slowness and speed are relative concepts. A household windmill at 300 rpm can be low-speed, but powerful APUs of the EuroWind type, from which the fields of wind power plants and wind farms are assembled (see figure) and whose rotors make about 10 rpm, are high-speed, because with such a diameter, the linear speed of the blades and their aerodynamics over most of the span are quite “airplane-like”, see below.

What kind of generator do you need?

An electric generator for a domestic windmill must generate electricity over a wide range of rotation speeds and be able to self-start without automation or external power sources. In the case of using APU with OSS (spin-up wind turbines), which, as a rule, have high KIEV and efficiency, it must also be reversible, i.e. be able to work as an engine. At powers up to 5 kW, this condition is satisfied by electric machines with permanent magnets based on niobium (supermagnets); on steel or ferrite magnets you can count on no more than 0.5-0.7 kW.

Note: asynchronous generators alternating current or collector ones with a non-magnetized stator are completely unsuitable. When the wind force decreases, they will “go out” long before its speed drops to MPC, and then they will not start themselves.

The excellent “heart” of the APU with a power from 0.3 to 1-2 kW is obtained from an alternating current self-generator with a built-in rectifier; these are the majority now. First, they maintain an output voltage of 11.6-14.7 V over a fairly wide speed range without external electronic stabilizers. Secondly, the silicon valves open when the voltage on the winding reaches approximately 1.4 V, and before that the generator “does not see” the load. To do this, the generator needs to be spun up quite decently.

In most cases, a self-generator can be directly connected, without a gear or belt drive, to the shaft of a high-speed high-pressure engine, selecting the speed by selecting the number of blades, see below. “High-speed trains” have a small or zero starting torque, but the rotor, even without disconnecting the load, will have time to spin sufficiently before the valves open and the generator produces current.

Choosing according to the wind

Before deciding what type of wind generator to make, let’s decide on the local aerology. In gray-greenish(windless) areas of the wind map, only a sailing wind engine will be of any use(We’ll talk about them later). If a constant power supply is required, you will have to add a booster (rectifier with voltage stabilizer), Charger, powerful battery, inverter 12/24/36/48 V DC to 220/380 V 50 Hz AC. Such a facility will cost no less than $20,000, and it is unlikely that it will be possible to remove long-term power of more than 3-4 kW. In general, with an unwavering desire for alternative energy, it is better to look for another source.

In yellow-green, low-wind places, with a need for electricity of up to 2-3 kW, you can take on a low-speed one yourself vertical wind generator . There are countless of them developed, and there are designs that are almost as good as industrially manufactured “blade blades” in terms of KIEV and efficiency.

If you plan to buy a wind turbine for your home, then it is better to focus on a wind turbine with a sail rotor. There are many controversies, and in theory everything is not yet clear, but they work. In the Russian Federation, “sailboats” are produced in Taganrog with a power of 1-100 kW.

In red, windy regions, the choice depends on the required power. In the range of 0.5-1.5 kW, homemade “verticals” are justified; 1.5-5 kW – purchased “sailboats”. “Vertical” can also be purchased, but will cost more than a horizontal APU. And finally, if you need a wind turbine with a power of 5 kW or more, then you need to choose between horizontal purchased “blades” or “sailboats”.

Note: Many manufacturers, especially the second tier, offer kits of parts from which you can assemble a wind generator with a power of up to 10 kW yourself. Such a kit will cost 20-50% less than a ready-made kit with installation. But before purchasing, you need to carefully study the aerology of the intended installation location, and then select according to the specifications suitable type and model.

About security

The parts of a wind turbine for household use in operation can have a linear speed exceeding 120 and even 150 m/s, and a piece of any solid material weighing 20 g, flying at a speed of 100 m/s, with a “successful” hit, will kill a healthy man outright. A steel or hard plastic plate 2 mm thick, moving at a speed of 20 m/s, cuts it in half.

In addition, most wind turbines with a power of more than 100 W are quite noisy. Many generate air pressure fluctuations of ultra-low (less than 16 Hz) frequencies - infrasounds. Infrasounds are inaudible, but are harmful to health and travel very far.

Note: in the late 80s there was a scandal in the United States - the largest wind farm in the country at that time had to be closed. Indians from a reservation 200 km from the field of its wind farm proved in court that their health disorders, which sharply increased after the wind farm was put into operation, were caused by its infrasounds.

Due to the above reasons, installation of APUs is allowed at a distance of at least 5 of their heights from the nearest residential buildings. In the courtyards of private households, it is possible to install industrially manufactured windmills that are appropriately certified. It is generally impossible to install APUs on roofs - during their operation, even low-power ones, alternating mechanical loads arise that can cause resonance of the building structure and its destruction.

Note: The height of the APU is considered to be the highest point of the swept disk (for bladed rotors) or geometric figure (for vertical APUs with a rotor on the shaft). If the APU mast or the rotor axis protrude even higher, the height is calculated by their top - the top.

Wind, aerodynamics, KIEV

A homemade wind generator obeys the same laws of nature as a factory one, calculated on a computer. And the home-made worker needs to understand the basics of his work very well - most often he does not have at his disposal expensive, cutting-edge materials and technological equipment. The aerodynamics of the APU are oh so difficult...

Wind and KIEV

To calculate serial factory APUs, the so-called. flat mechanistic model of wind. It is based on the following assumptions:

• Wind speed and direction are constant within the effective rotor surface.
• Air is a continuous medium.
• The effective surface of the rotor is equal to the swept area.
• The energy of the air flow is purely kinetic.

Under such conditions maximum energy air volume units are calculated using the school formula, assuming the air density under normal conditions is 1.29 kg*cubic. m. At a wind speed of 10 m/s, one cube of air carries 65 J, and from one square of the effective surface of the rotor, with 100% efficiency of the entire APU, 650 W can be removed. This is a very simplified approach - everyone knows that the wind is never perfectly even. But this has to be done to ensure repeatability of products - a common thing in technology.

The flat model should not be ignored; it provides a clear minimum available energy wind. But air, firstly, is compressible, and secondly, it is very fluid (dynamic viscosity is only 17.2 μPa * s). This means that the flow can flow around the swept area, reducing the effective surface and KIEV, which is most often observed. But in principle, the opposite situation is also possible: the wind flows towards the rotor and the effective surface area will then be greater than the swept one, and the KIEV will be greater than 1 relative to it for a flat wind.

Let's give two examples. The first is a pleasure yacht, quite heavy; the yacht can sail not only against the wind, but also faster than it. Wind means external; the apparent wind must still be faster, otherwise how will it pull the ship?

The second is a classic of aviation history. During tests of the MIG-19, it turned out that the interceptor, which was a ton heavier than the front-line fighter, accelerates faster in speed. With the same engines in the same airframe.

The theorists did not know what to think, and seriously doubted the law of conservation of energy. In the end, it turned out that the problem was the cone of the radar radome protruding from the air intake. From its toe to the shell, an air compaction arose, as if raking it from the sides to the engine compressors. Since then, shock waves have become firmly established in theory as useful, and the fantastic flight performance of modern aircraft is due in no small part to their skillful use.

Aerodynamics

The development of aerodynamics is usually divided into two eras - before N. G. Zhukovsky and after. His report “On attached vortices” dated November 15, 1905 was the beginning new era in aviation.

Before Zhukovsky, they flew with flat sails: it was assumed that the particles of the oncoming flow gave all their momentum to the leading edge of the wing. This made it possible to immediately get rid of the vector quantity - angular momentum - which gave rise to tooth-breaking and most often non-analytical mathematics, move to much more convenient scalar purely energy relations, and ultimately obtain a calculated pressure field on the load-bearing plane, more or less similar to the real one.

This mechanistic approach made it possible to create devices that could, at the very least, take to the air and fly from one place to another, without necessarily crashing to the ground somewhere along the way. But the desire to increase speed, load capacity and other flight qualities increasingly revealed the imperfections of the original aerodynamic theory.

Zhukovsky's idea was this: the air travels a different path along the upper and lower surfaces of the wing. From the condition of continuity of the medium (vacuum bubbles by themselves do not form in the air) it follows that the velocities of the upper and lower flows descending from the trailing edge should be different. Due to the small but finite viscosity of the air, a vortex should form there due to the difference in speeds.

The vortex rotates, and the law of conservation of momentum, just as immutable as the law of conservation of energy, is also valid for vector quantities, i.e. must also take into account the direction of movement. Therefore, right there, on the trailing edge, a counter-rotating vortex with the same torque should form. Due to what? Due to the energy generated by the engine.

For aviation practice, this meant a revolution: by choosing the appropriate wing profile, it was possible to send an attached vortex around the wing in the form of a circulation G, increasing its lift. That is, by spending part, and for high speeds and loads on the wing – most of the motor power, you can create an air flow around the device, allowing you to achieve better flight qualities.

This made aviation aviation, and not part of aeronautics: now aircraft could create for himself the environment necessary for flight and no longer be a toy of air currents. All you need is a more powerful engine, and more and more powerful...

KIEV again

But the windmill does not have a motor. On the contrary, it must take energy from the wind and give it to consumers. And here it turns out - his legs were pulled out, his tail got stuck. We used too little wind energy for the rotor’s own circulation - it will be weak, the thrust of the blades will be low, and the KIEV and power will be low. We give a lot to the circulation - in a weak wind, the rotor will spin like crazy at idle, but consumers again get little: they just put on a load, the rotor slowed down, the wind blew away the circulation, and the rotor stopped working.

The law of conservation of energy gives the “golden mean” right in the middle: we give 50% of the energy to the load, and for the remaining 50% we turn up the flow to the optimum. Practice confirms the assumptions: if the efficiency of a good pulling propeller is 75-80%, then the efficiency of a bladed rotor that is also carefully calculated and blown in a wind tunnel reaches 38-40%, i.e. up to half of what can be achieved with excess energy.

Modernity

Nowadays, aerodynamics, armed with modern mathematics and computers, is increasingly moving away from inevitably simplifying models towards an accurate description of the behavior of a real body in a real flow. And here, in addition to the general line - power, power, and once again power! – side paths are discovered, but promising precisely when the amount of energy entering the system is limited.

The famous alternative aviator Paul McCready created an airplane back in the 80s with two chainsaw motors with a power of 16 hp. showing 360 km/h. Moreover, its chassis was tricycle, non-retractable, and its wheels were without fairings. None of McCready's devices went online or went on combat duty, but two - one with piston engines and propellers, and the other a jet - for the first time in history flew around the globe without landing at the same gas station.

The development of the theory also affected the sails that gave birth to the original wing quite significantly. “Live” aerodynamics allowed the yachts to operate in winds of 8 knots. stand on hydrofoils (see figure); to accelerate such a monster to the required speed with a propeller, an engine of at least 100 hp is required. Racing catamarans sail at a speed of about 30 knots in the same wind. (55 km/h).

There are also finds that are completely non-trivial. Fans of the rarest and most extreme sport - base jumping - wearing a special wing suit, wingsuit, fly without a motor, maneuvering at a speed of more than 200 km/h (picture on the right), and then smoothly land in a pre-selected place. In which fairy tale do people fly on their own?

Many mysteries of nature were also resolved; in particular, the flight of a beetle. According to classical aerodynamics, it is not capable of flying. Just like the founder of the stealth aircraft, the F-117, with its diamond-shaped wing, is also unable to take off. And the MIG-29 and Su-27, which can fly tail first for some time, do not fit into any idea at all.

And why then, when working on wind turbines, is it not fun and not a tool for destroying one’s own kind, but a source of life? important resource, is it necessary to dance away from the theory of weak flows with its flat wind model? Is there really no way to move forward?

What to expect from the classics?

However, one should not abandon the classics under any circumstances. It provides a foundation without which one cannot rise higher without relying on it. Just as set theory does not abolish the multiplication table, and quantum chromodynamics will not make apples fly up from the trees.

So, what can you expect with the classical approach? Let's look at the picture. On the left are types of rotors; they are depicted conditionally. 1 – vertical carousel, 2 – vertical orthogonal ( wind turbine); 2-5 – bladed rotors with different quantities blades with optimized profiles.

On the right along the horizontal axis is the relative speed of the rotor, i.e., the ratio of the linear speed of the blade to the wind speed. Vertical up - KIEV. And down - again, relative torque. A single (100%) torque is considered to be that which is created by a rotor forcibly braked in the flow with 100% KIEV, i.e. when all the flow energy is converted into rotating force.

This approach allows us to draw far-reaching conclusions. For example, the number of blades must be selected not only and not so much according to the desired rotation speed: 3- and 4-blades immediately lose a lot in terms of KIEV and torque compared to 2- and 6-blades that work well in approximately the same speed range. And the outwardly similar carousel and orthogonal have fundamentally different properties.

In general, preference should be given to bladed rotors, except in cases where extreme low cost, simplicity, maintenance-free self-starting without automation are required, and lifting onto a mast is impossible.

Note: Let's talk about sailing rotors in particular - they don't seem to fit into the classics.

Verticals

APU with vertical axis rotations have an undeniable advantage for everyday life: their units that require maintenance are concentrated at the bottom and there is no need to go upstairs. There remains, and even then not always, a thrust-support self-aligning bearing, but it is strong and durable. Therefore, when designing a simple wind generator, the selection of options should begin with verticals. Their main types are presented in Fig.

Sun

In the first position is the simplest one, most often called the Savonius rotor. In fact, it was invented in 1924 in the USSR by J. A. and A. A. Voronin, and the Finnish industrialist Sigurd Savonius shamelessly appropriated the invention, ignoring the Soviet copyright certificate, and began serial production. But the introduction of an invention in the future means a lot, so in order not to stir up the past and not disturb the ashes of the deceased, we will call this windmill a Voronin-Savonius rotor, or for short, VS.

The aircraft is good for the home-made man, except for the “locomotive” KIEV at 10-18%. However, in the USSR they worked a lot on it, and there are developments. Below we will look at an improved design, not much more complex, but according to KIEV, it gives bladers a head start.

Note: the two-blade aircraft does not spin, but jerks jerkily; The 4-blade is only slightly smoother, but loses a lot in KIEV. To improve, 4-trough blades are most often divided into two floors - a pair of blades below, and another pair, rotated 90 degrees horizontally, above them. KIEV is preserved, and the lateral loads on the mechanics weaken, but the bending loads increase somewhat, and with a wind of more than 25 m/s such an APU is on the shaft, i.e. without a bearing stretched by cables above the rotor, it “tears down the tower.”

Daria

Next is the Daria rotor; KIEV – up to 20%. It is even simpler: the blades are made of a simple elastic tape without any profile. The theory of the Darrieus rotor is not yet sufficiently developed. It is only clear that it begins to unwind due to the difference aerodynamic drag hump and pocket of the tape, and then becomes sort of high-speed, forming its own circulation.

The torque is small, and in the starting positions of the rotor parallel and perpendicular to the wind it is completely absent, so self-spin is possible only with an odd number of blades (wings?) In any case, the load from the generator must be disconnected during spin-up.

The Daria rotor has two more bad qualities. Firstly, when rotating, the thrust vector of the blade describes a full rotation relative to its aerodynamic focus, and not smoothly, but jerkily. Therefore, the Darrieus rotor quickly breaks down its mechanics even in a steady wind.

Secondly, Daria not only makes noise, but screams and squeals, to the point that the tape breaks. This happens due to its vibration. And the more blades, the stronger the roar. So, if they make a Daria, it is with two blades, from expensive high-strength sound-absorbing materials (carbon, mylar), and a small aircraft is used for spinning in the middle of the mast-pole.

Orthogonal

At pos. 3 – orthogonal vertical rotor with profiled blades. Orthogonal because the wings stick out vertically. The transition from BC to orthogonal is illustrated in Fig. left.

The angle of installation of the blades relative to the tangent to the circle touching the aerodynamic foci of the wings can be either positive (in the figure) or negative, depending on the wind force. Sometimes the blades are made rotating and weather vanes are placed on them, automatically holding the “alpha”, but such structures often break.

The central body (blue in the figure) allows you to increase the KIEV to almost 50%. In a three-blade orthogonal, it should have the shape of a triangle in cross-section with slightly convex sides and rounded corners, and with a larger number of blades, a simple cylinder is sufficient. But the theory for the orthogonal gives an unambiguous optimal number of blades: there should be exactly 3 of them.

Orthogonal refers to high-speed wind turbines with OSS, i.e. necessarily requires promotion during commissioning and after calm. According to the orthogonal scheme, serial maintenance-free APUs with a power of up to 20 kW are produced.

Helicoid

Helicoidal rotor, or Gorlov rotor (item 4) is a type of orthogonal that ensures uniform rotation; an orthogonal with straight wings “tears” only slightly weaker than a two-bladed aircraft. Bending the blades along a helicoid allows one to avoid losses of CIEV due to their curvature. Although the curved blade rejects part of the flow without using it, it also scoops part into the zone of highest linear speed, compensating for losses. Helicoids are used less often than other wind turbines, because Due to the complexity of manufacturing, they are more expensive than their counterparts of equal quality.

Barrel raking

For 5 pos. – BC type rotor surrounded by a guide vane; its diagram is shown in Fig. on right. IN industrial version It is rare because expensive land acquisition does not compensate for the increase in capacity, and the material consumption and complexity of production are high. But a do-it-yourselfer who is afraid of work is no longer a master, but a consumer, and if you need no more than 0.5-1.5 kW, then for him a “barrel-raking” is a tidbit:

• A rotor of this type is absolutely safe, silent, does not create vibrations and can be installed anywhere, even on a playground.
• Bending a galvanized “trough” and welding a frame of pipes is nonsense work.
• Rotation is absolutely uniform, mechanical parts can be taken from the cheapest or from the trash.
• Not afraid of hurricanes - too strong a wind cannot push into the “barrel”; a streamlined vortex cocoon appears around it (we will encounter this effect later).
• And the most important thing is that since the surface of the “barrel” is several times larger than that of the rotor inside, the KIEV can be over-unit, and the rotational moment already at 3 m/s for a “barrel” of three-meter diameter is such that a 1 kW generator with a maximum load of They say it’s better not to twitch.

Video: Lenz wind generator

In the 60s in the USSR, E. S. Biryukov patented a carousel APU with a KIEV of 46%. A little later, V. Blinov achieved 58% KIEV from a design based on the same principle, but there is no data on its testing. And full-scale tests of Biryukov’s APU were carried out by employees of the magazine “Inventor and Innovator”. A two-story rotor with a diameter of 0.75 m and a height of 2 m in a fresh wind spun a 1.2 kW asynchronous generator to full power and withstood 30 m/s without breakdown. Drawings of Biryukov's APU are shown in Fig.

1. rotor made of galvanized roofing;
2. self-aligning double row ball bearing;
3. shrouds – 5 mm steel cable;
4. axis-shaft – steel pipe with a wall thickness of 1.5-2.5 mm;
5. aerodynamic speed control levers;
6. speed control blades – 3-4 mm plywood or sheet plastic;
7. speed control rods;
8. speed controller load, its weight determines the rotation speed;
9. drive pulley - a bicycle wheel without a tire with a tube;
10. thrust bearing - thrust bearing;
11. driven pulley – standard generator pulley;
12. generator.

Biryukov received several copyright certificates for his Armed Forces. First, pay attention to the cut of the rotor. When accelerating, it works like an aircraft, creating a large starting torque. As it spins, a vortex cushion is created in the outer pockets of the blades. From the wind's point of view, the blades become profiled and the rotor becomes a high-speed orthogonal, with the virtual profile changing according to the wind strength.

Secondly, the profiled channel between the blades acts as a central body in the operating speed range. If the wind intensifies, then a vortex cushion is also created in it, extending beyond the rotor. The same vortex cocoon appears as around the APU with a guide vane. The energy for its creation is taken from the wind, and it is no longer enough to break the windmill.

Thirdly, the speed controller is intended primarily for the turbine. It keeps its speed optimal from the KIEV point of view. And the optimum generator rotation speed is ensured by choosing gear ratio mechanics.

Note: after publications in the IR for 1965, the Armed Forces of Ukraine Biryukova sank into oblivion. The author never received a response from the authorities. The fate of many Soviet inventions. They say that some Japanese became a billionaire by regularly reading Soviet popular-technical magazines and patenting everything worthy of attention.

Lopastniki

As stated, according to the classics, a horizontal wind generator with a bladed rotor is the best. But, firstly, it needs a stable wind of at least medium strength. Secondly, the design for a do-it-yourselfer is fraught with many pitfalls, which is why often the fruit of long hard work, at best, illuminates a toilet, hallway or porch, or even turns out to only be able to unwind itself.

According to the diagrams in Fig. Let's take a closer look; positions:

• Fig. A:

1. rotor blades;
2. generator;
3. generator frame;
4. protective weather vane (hurricane shovel);
5. current collector;
6. chassis;
7. swivel unit;
8. working weather vane;
9. mast;
10. clamp for the shrouds.

• Fig. B, top view:

1. protective weather vane;
2. working weather vane;
3. protective weather vane spring tension regulator.

• Fig. G, current collector:

1. collector with copper continuous ring busbars;
2. spring-loaded copper-graphite brushes.

Note: Hurricane protection for a horizontal blade with a diameter of more than 1 m is absolutely necessary, because he is not capable of creating a vortex cocoon around himself. With smaller sizes, it is possible to achieve a rotor endurance of up to 30 m/s with propylene blades.

So, where do we stumble?

Blades

Expect to achieve power on the generator shaft of more than 150-200 W on blades of any size cut from thick-walled plastic pipe, as is often advised, are the hopes of a hopeless amateur. A pipe blade (unless it is so thick that it is simply used as a blank) will have a segmented profile, i.e. its top or both surfaces will be arcs of a circle.

Segmented profiles are suitable for incompressible media, say hydrofoils or blades propeller. For gases, a blade of variable profile and pitch is needed, for an example, see Fig.; span - 2 m. This will be a complex and labor-intensive product, requiring painstaking calculations in full theory, blowing in a pipe and full-scale testing.

Generator

If the rotor is mounted directly on its shaft, the standard bearing will soon break - there is no equal load on all the blades in windmills. You need an intermediate shaft with a special support bearing and a mechanical transmission from it to the generator. For large windmills, the support bearing is a self-aligning double-row one; V best models– three-tiered, Fig. D in Fig. higher. This allows the rotor shaft not only to bend slightly, but also to move slightly from side to side or up and down.

Note: It took about 30 years to develop a support bearing for the EuroWind type APU.

Emergency weather vane

The principle of its operation is shown in Fig. B. The wind, intensifying, puts pressure on the shovel, the spring stretches, the rotor warps, its speed drops and eventually it becomes parallel to the flow. Everything seems to be fine, but it was smooth on paper...

On a windy day, try holding a boiler lid or a large saucepan by the handle parallel to the wind. Just be careful - the fidgety piece of iron can hit you in the face so hard that it breaks your nose, cuts your lip, or even knocks out your eye.

Flat wind occurs only in theoretical calculations and, with sufficient accuracy for practice, in wind tunnels. In reality, a hurricane damages windmills with a hurricane shovel more than completely defenseless ones. It’s better to change damaged blades than to do everything again. In industrial installations it is a different matter. There, the pitch of the blades, each individually, is monitored and adjusted by automation under the control of the on-board computer. And they are made from heavy-duty composites, not water pipes.

Current collector

This is a regularly serviced unit. Any power engineer knows that the commutator with brushes needs to be cleaned, lubricated, and adjusted. And the mast is from water pipe. If you can’t climb, once every month or two you’ll have to throw the entire windmill down to the ground and then pick it up again. How long will he last from such “prevention”?

Video: bladed wind generator + solar panel for power supply to a dacha

Mini and micro

But as the size of the paddle decreases, the difficulties fall according to the square of the wheel diameter. It is already possible to manufacture a horizontal bladed APU on your own with a power of up to 100 W. A 6-bladed one would be optimal. With more blades, the diameter of the rotor designed for the same power will be smaller, but they will be difficult to firmly attach to the hub. Rotors with less than 6 blades need not be taken into account: a 2-blade 100 W rotor needs a rotor with a diameter of 6.34 m, and a 4-blade of the same power needs 4.5 m. For a 6-blade, the power-diameter relationship is expressed as follows :

• 10 W – 1.16 m.
• 20 W – 1.64 m.
• 30 W – 2 m.
• 40 W – 2.32 m.
• 50 W – 2.6 m.
• 60 W – 2.84 m.
• 70 W – 3.08 m.
• 80 W – 3.28 m.
• 90 W – 3.48 m.
• 100 W – 3.68 m.
• 300 W – 6.34 m.

It would be optimal to count on a power of 10-20 W. Firstly, a plastic blade with a span of more than 0.8 m will not withstand winds of more than 20 m/s without additional protection measures. Secondly, with a blade span of up to the same 0.8 m, the linear speed of its ends will not exceed the wind speed by more than three times, and the requirements for profiling with twist are reduced by orders of magnitude; here a “trough” with a segmented pipe profile, pos. B in Fig. And 10-20 W will provide power to a tablet, recharge a smartphone, or illuminate a house-saving light bulb.

Next, select a generator. A Chinese motor is perfect - wheel hub for electric bicycles, pos. 1 in Fig. Its power as a motor is 200-300 W, but in generator mode it will give up to about 100 W. But will it suit us in terms of speed?

The speed index z for 6 blades is 3. The formula for calculating the rotation speed under load is N = v/l*z*60, where N is the rotation speed, 1/min, v is the wind speed, and l is the rotor circumference. With a blade span of 0.8 m and a wind of 5 m/s, we get 72 rpm; at 20 m/s – 288 rpm. A bicycle wheel also rotates at approximately the same speed, so we will take off our 10-20 W from a generator capable of producing 100. You can place the rotor directly on its shaft.

But here the following problem arises: after spending a lot of work and money, at least on a motor, we got... a toy! What is 10-20, well, 50 W? But you can’t make a bladed windmill capable of powering even a TV at home. Is it possible to buy a ready-made mini-wind generator, and wouldn’t it be cheaper? As much as possible, and as cheaply as possible, see pos. 4 and 5. In addition, it will also be mobile. Place it on a stump and use it.

The second option is if a stepper motor from an old 5- or 8-inch floppy drive is lying around somewhere, or from a paper drive or carriage of an unusable inkjet or dot matrix printer. It can work as a generator, and attaching a carousel rotor from cans to it (pos. 6) is easier than assembling a structure like the one shown in pos. 3.

In general, the conclusion regarding “blade blades” is clear: homemade ones are more likely for tinkering to your heart’s content, but not for real long-term energy output.

Video: the simplest wind generator for lighting a dacha

Sailboats

The sailing wind generator has been known for a long time, but soft panels on its blades (see figure) began to be made with the advent of high-strength, wear-resistant synthetic fabrics and films. Multi-bladed windmills with rigid sails are widely used around the world as a drive for low-power automatic water pumps, but their technical specifications are lower even than those of carousels.

However, a soft sail like a windmill wing, it seems, turned out to be not so simple. The point is not about wind resistance (manufacturers do not limit the maximum permissible wind speed): sailboat sailors already know that it is almost impossible for the wind to tear the panel of a Bermuda sail. Most likely, the sheet will be torn out, or the mast will be broken, or the whole vessel will make an “overkill turn.” It's about energy.

Unfortunately, exact test data cannot be found. Based on user reviews, it was possible to create “synthetic” dependencies for the installation of a Taganrog-made wind turbine-4.380/220.50 with a wind wheel diameter of 5 m, a wind head weight of 160 kg and a rotation speed of up to 40 1/min; they are presented in Fig.

Of course, there can be no guarantees for 100% reliability, but it is clear that there is no smell of a flat-mechanistic model here. There is no way a 5-meter wheel in a flat wind of 3 m/s can produce about 1 kW, at 7 m/s reach a plateau in power and then maintain it until a severe storm. Manufacturers, by the way, state that the nominal 4 kW can be obtained at 3 m/s, but when installed by forces based on the results of studies of local aerology.

There is also no quantitative theory to be found; The developers' explanations are unclear. However, since people buy Taganrog wind turbines and they work, we can only assume that the declared conical circulation and propulsive effect are not a fiction. In any case, they are possible.

Then, it turns out, IN FRONT of the rotor, according to the law of conservation of momentum, a conical vortex should also arise, but expanding and slow. And such a funnel will drive the wind towards the rotor, its effective surface will be more swept, and the KIEV will be more than unity.

Field measurements of the pressure field in front of the rotor, even with a household aneroid, could shed light on this issue. If it turns out to be higher than on the sides, then, indeed, the sailing APUs work like a beetle flies.

Homemade generator

From what has been said above, it is clear that it is better for homemade craftsmen to take on either verticals or sailboats. But both are very slow, and transmission to a high-speed generator is extra work, extra costs and losses. Is it possible to make an efficient low-speed electric generator yourself?

Yes, you can, on magnets made of niobium alloy, so-called. supermagnets. The manufacturing process of the main parts is shown in Fig. Coils - each of 55 turns of 1 mm copper wire in heat-resistant high-strength enamel insulation, PEMM, PETV, etc. The height of the windings is 9 mm.

Pay attention to the grooves for the keys in the rotor halves. They must be positioned so that the magnets (they are glued to the magnetic core with epoxy or acrylic) converge with opposite poles after assembly. “Pancakes” (magnetic cores) must be made of a soft magnetic ferromagnet; Regular structural steel will do. The thickness of the “pancakes” is at least 6 mm.

In general, it is better to buy magnets with an axial hole and tighten them with screws; supermagnets attract with terrible force. For the same reason, a cylindrical spacer 12 mm high is placed on the shaft between the “pancakes”.

The windings that make up the stator sections are connected according to the diagrams also shown in Fig. The soldered ends should not be stretched, but should form loops, otherwise the epoxy with which the stator will be filled may harden and break the wires.

The stator is poured into the mold to a thickness of 10 mm. There is no need to center or balance, the stator does not rotate. The gap between the rotor and stator is 1 mm on each side. The stator in the generator housing must be securely secured not only from displacement along the axis, but also from rotation; a strong magnetic field with current in the load will pull it along with it.

Video: DIY windmill generator

Conclusion

And what do we have in the end? The interest in “blade blades” is explained rather by their spectacular appearance than real performance qualities in a homemade version and at low power. A homemade carousel APU will provide “standby” power for charging a car battery or powering a small house.

But with sailing APUs it is worth experimenting with craftsmen with a creative streak, especially in the mini version, with a wheel 1-2 m in diameter. If the developers’ assumptions are correct, then it will be possible to remove all 200-300 W from this one, using the Chinese engine-generator described above.

Andrey said:

Thank you for your free consultation... And the prices “from companies” are not really expensive, and I think that craftsmen from the outback will be able to make generators similar to yours. And Li-po batteries can be ordered from China, inverters in Chelyabinsk make very good ones (with smooth sine). And sails, blades or rotors are another reason for the flight of thought of our handy Russian men.

Ivan said:

question:
For windmills with a vertical axis (position 1) and the “Lenz” option, it is possible to add an additional part - an impeller that points in the direction of the wind, and covers the useless side from it (going towards the wind). That is, the wind will not slow down the blade, but this “screen”. Positioning downwind with the “tail” located behind the windmill itself below and above the blades (ridges). I read the article and an idea was born.

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