Report.docx

Bladeless windmill

Abstract Today, India is top amongst the list of developing countries in terms of economic development. Hence the energy requirement is increasing rapidly. To meet these energy requirements non-renewable energy sources are used excessively but due to limited storage of this sources there is a need for generation of clean energy through renewable energy sources. India is having fifth largest installed wind power capacity in the world. As the region of high speed wind is limited and also the area required for installation of conventional windmill is high, bladeless windmill based on vortex induced vibrations can provide the solution for these disadvantages of the conventional windmill. Bladeless windmill basically works on the vortex shedding effect. The device is composed of a single structural component, and given its morphological simplicity, its manufacturing, transport, storage and installation has clear advantages. The new wind turbine design has no bearings, gears, so the maintenance requirements could be drastically reduced and their lifespan is expected to be higher than traditional wind turbines. Generally structures are designed to avoid vortex induced vibrations in order to minimize the mechanical failures. But here, we try to increase the vibrations to increase the generation of electricity

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Bladeless windmill

Introduction

As we know that the sun is the source of energy. We get the energy from sun as well as other sources but still people's are facing the problems of energy crisis that is the available sources of energy is insufficient satisfy the needs of the customers. In 21th century it is important to satisfy the increasing demand of the industries & people's working in other professions. In order to satisfy this increasing demand of the customers we cannot totally depend on only one source of energy hence we need to find alternate sources with sun like wind. Then the wind is used as a alternate source. The windmills are install in hilly areas at a certain heights. Windmill converts the kinetic energy of the wind into the rotational energy of blade & after electrical devices the required electrical energy is obtained. The annual growth rate of India for wind energy generation only 21% & the Denmark is only the place who utilizes the large amount wind energy for their demand. The annual growth rate of Denmark is about 42.24% which more than India but Denmark uses more advance technology than India.

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Bladeless windmill

Fig 1

As we see the graph of electrical energy obtained from windmill since 2006 to 2018 there is increase in wind power generation from 7850MW to 34.294GW.This is better growth of our economy which is required for our sustainable development but it has also some problems like it requires certain height for installation & it produces low frequency signals which are hazardous for human health. The many birds die due to blades of windmills hence we need to protect human life as well as birds. To protect our environment bodies bladeless windmills plays very important role. The energy generation from traditional wind mill is very costly because it requires more maintenance & it is also difficult to transport. IT also affects our rainfall conditions which creates barrier for our rainfall due to his tall heights. But the bladeless windmill requires considerably less space than traditional one. It doesn't affect our environmental conditions & it doesn't harm birds. It creates 10times more energy than traditional one is the main benefit of his. The bladeless windmill is 40% more efficient than conventional windmill. It changes its direction according to the air flow conditions & produce energy. Bladeless windmill shack back & forth about its central conditions & transfer its motion totheir mechanisms for energy generation. The main advantage of this is that it has less number of moving parts which doesn't act as a hindrance for operation. construction is also simple & the maintenance cost of the windmill is also less. It helps to improve the economical growth of our nation & also satisfy the needs of our nation.

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Bladeless windmill

Study Of Vortex Induced Vibrations VIV Theory : VIV is a result of vortex shedding phenomenon which generally occurs nearly on any bluff body when submerged into fluid flow. Normally, irregular vortex shedding will occur. Flow behind the bodyresulting in the fluctuating pressure differential which produces liftforce perpendicular to the direction of the flow. The oscillatingmotion on the body is due to alternating lift forces.

Reynolds Number: In general, flow parameter that affects the behavior of vortexshedding has been observed to be the Reynolds number of flow asRe = (U D)/ν (1) U is the free-stream velocity, D is the cylinder diameter and ν is the fluid kinematic viscosity. The regime that is targeted in this project isknown as the “fully turbulent vortex street”, with Reynolds numberin the range of (300
Strouhal Number: The Strouhal Number, St is a non-dimensional parameter thatdescribes the vortex shedding frequency to the oscillating flowmechanism . St = (fs D)/U (2) Where, fsis vortex shedding frequency. Strouhal number will be used as a constant value in this project asthe Reynolds number falls in the middle of constant Strouhal numberregion which is 0.2 for subcritical flow. Lock In Phenomenon: A phenomenon known as “lock in” is a condition when the vortexshedding frequency becomes close to the natural frequency of the body. It has the potential to enlarge the amplitudes of bodies’ oscillation which is similar to linear resonance.

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Bladeless windmill

Fig 2

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Bladeless windmill

Literature Survey Bladeless Wind Turbine uses a radically new approach to capturing wind energy. Our device captures the energy of vorticity, an aerodynamic effect that has plagued structural engineers and architects for ages (vortex shedding effect). As the wind bypasses a fixed structure, its flow changes and generates a cyclical pattern of vortices. Once theseforces are strong enough, the fixed structure starts oscillating, may enter into resonance with the lateral forces of the wind, and even collapse. There is a classic academic example of the Tacoma Narrows Bridge, which collapsed three months after its inauguration because of the Vortex

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Bladeless windmill

Fig 2

Research paper

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Bladeless windmill

shedding effect as well as effects of flattering and galloping. Instead of avoiding these aerodynamic instabilities our technology maximizes the Page 8 PC Polytechnic, Mechanical Department

Bladeless windmill resulting oscillation and captures that energy. Naturally, the design of such device is completely different from a traditional turbine. Instead of the usual tower, nacelle and blades, our device has a fixed mast, a power generator and a hollow, lightweight and semi-rigid fiberglass cylinder on top. The Bladeless Turbine harness vorticity, the spinning motion of air or other fluids. When wind passes one of the cylindrical turbines, it shears off the downwind side of the cylinder in a spinning whirlpool or vortex. That vortex then exerts force on the cylinder, causing it to vibrate. The kinetic energy of the oscillating cylinder is converted to electricity through a linear generator similar to those used to harness wave energy.This puts the technology at the very low range of capital intensity for such projects, it also makes it highly competitive not only against generations of alternative or renewable energy, but even compared to conventional technologies.

PROBLEM OF TRADITIONAL WINDMILL 1) Wind resource development might not be the most profitable use of the land. Land suitable for wind-turbine installation must compete with alternative uses for the land, which might be more highly valued than electricity generation. 2) Turbines might cause noise and aesthetic pollution. Although wind power plants have relatively little impact on the environment compared to conventional power plants, concern exists over the noise produced by the turbine blades and visual impacts to the landscape. 3) Turbine blades could damage local wildlife. Birds have been killed by flying into spinning turbine blades. Most of these problems Wind power must still compete with conventional generation sources on a cost basis. Depending on how energetic a wind site is, the wind farm might not be cost competitive. Even though the cost of wind power has decreased dramatically in the past 10 years, the technology requires a higher initial investment than fossil-fueled generators.

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Bladeless windmill 4) Good wind sites are often located in remote locations, far from cities where the electricity is needed. Transmission lines must be built to bring the electricity from the wind farm to the city. However, building just a few already-proposed transmission lines could significantly reduce the costs of expanding have been resolved or greatly reduced through technological development or by properly siting wind plants.

Advantages of bladeless windmill: The main advantages of this project is as follows, 1. To increase the efficiency of wind power generation. 2. To produce clean energy to meet the increasing demands. 3. To make the wind energy economical and efficient. 4. Rural electrification. 5. To reduce pollution and global warming. 6. Development of the project so that it can be used on domestic purposes. 7. To reduce the manufacturing cost of the turbine. 8. It aims to be a ‘Greener’ Wind alternative leaving less carbon footprint on the Environment

PRINCIPLE OF OPERATION (METHODOLOGY)

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Bladeless windmill The main principle behind this project is the conversion of linear oscillation of mast torotational motion. As the mast is subjected to wind energy, it tends to oscillate due to thevortices formed around the structure of the mast, which can be converted to rotational forceto generate electricity. In the bladeless wind system configuration, the mast is fixed withrespect to the ground and the rib structure at the top of the mast comprising of threadarrangement is used for pulling the threads attached to it. Energy is obtained by continuouslyoscillation of the mast. The mast utilizes wind power to pull the threads along with the chainattached to the sprockets which drive the shaft which intern rotates the alternator to generate power.

During the oscillation of the mast, the mast tries to oscillate in any direction depending on the wind direction. The rib structure at the top of the mast is attached with six threads to absorb the energy from the wind. Each set of the thread arrangement of the rib structure corresponds to one sprocket on the shaft which is driven by the chain which is pulled by the thread. Hence three sprockets are available in the shaft out of which one of the sprockets always is always in motionduring the oscillation of the mast. The arrangement of the threads on the mast is such that the power is generated on all direction of oscillation of the mast. Each of the threads is joined with the chain which drives the sprocket attached to the shaft to generate the maximum amount of power. The thread joined with the chain is fixed with a spring mechanism, during the oscillation of the mast one of the six threads is pulled which make the chain to drive the sprocket on the shaft. After the maximum oscillation on one side is reached, the mast returns to its initial position and then continues the oscillation on the other side where in the otherarrangement of the threads and sprocket drives the shaft hence providing the continues movement of the shaft. Such operation has been developed and tested through numerical simulations, considering a quite accurate model, which takes into account the aerodynamic characteristics of the mast and the strength of the threads, and employing self-tuning

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Bladeless windmill magnetic coupling system to maximize thenet generated energy. So that it can operate in a wider range of wind speeds and also withstand the high wind velocities. This system allows maximizing the oscillation amplitudes when wind intensifies.When the wind strikes the mast, it starts to oscillate due to the vortices formed around the structure and suspension spring placed at the bottom of the mast. The energy absorbed by the spring during the oscillation of the mast contributes to the increase in the amplitude of theoscillations. The rib structure with the six thread arrangement at the top of the mast is attached to the bottom chain drives through the guide ways which helps the mast to oscillate in any direction of the wind. During the back and forth oscillation of the mast, one of the six threads is pulledfrom the rib structure of the mast depending upon the direction of the wind. The thread being pulled due to the oscillation of the mast is connected to chain which drive the sprocket on the shaft. Each set of the thread arrangement of the rib structure corresponds to one sprocket on the shaft which is driven by the chain which is pulled by the thread. Hence t three sprockets are available in the shaft out of which one of the sprockets always is always in motion during the oscillation of the mast. The thread mechanism is provided with guide ways and pulleys for maximum transfer of the pulling force from the oscillation to the sprockets of the shaft. It also helps to increase the tensile strength of the threads which is necessary to increase the conversion efficiency to the maximum extent. The shaft driven by the sprockets arrangement rotates only in clockwise direction and restricts the rotation of the shaft in the opposite direction which otherwise may cause the threads to be pulled which may disrupt the oscillation of the mast and bring it to a halt. This shaft is welded with two bicycle pedal at the end spaced 180 degrees apart and the flywheel is provided with four counter weights 90 degrees apart, the arrangement of the pedal and the counterweight helps to increase the rotation of the flywheel. As the power is generated in the half cycle of the oscillation of the mast the shaft is subjected to a jerk motion rather than a smooth motion. Sucharrangement of pedal and the counterweight helps in the smooth rotation of the flywheel trying to achieve perpetual motion

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Bladeless windmill Data Collection

Understanding the vibration The idea behind Bladeless wind turbine is that it is possible that same forces canbe exploited to produce energy. When the wind vortices match the naturalfrequency of the device’s structure it begins resonating, hence oscillating, sothe bladeless wind turbine can harness energy from that movement as aregular generator. There are lots of examples of the Vortex Shedding effect in everyday life. Based on this principle, and bearing in mind some other physical phenomena, such as Betz’s law, finite bodies’ aerodynamics, turbulence regions, wind gradient, etc… the Vortex’s team have created lots of computational models which will shed light on the proper geometry and parameters to develop and improve the efficiency of Vortex design.

Block diagram of bladeless windmill

As shown in block diagram, when wind flows at some specific speed oscillations surrounding the pole of windmill Due to this the pole will oscillate. These oscillations Page 13 PC Polytechnic, Mechanical Department

Bladeless windmill will applied to the steady part of the windmill which is placed at the bottom. In the steady part we have placed either piezoelectric material or linear generator. Due to oscillation produced by the pole, vibrations will create in piezoelectric material. Due to vibrations there will be production of voltage which is dc in nature. We have to convert it into the ac voltage and step it up and then will give to the load. If we are going to use linear generator then the shaft of the linear generator will move horizontally due to oscillations of pole. There will be production of voltage which is ac in nature. We don’t have to use inverter when we are using the linear generator as the voltage produced is ac in nature so we can feed it to the load directly. This bladeless windmill has very high efficiency as there are minimum losses and this windmill will start energy production at very low speed of wind. This windmill will start to produce energy at speed of 1.3 meters/sec. i.e 4.6 km/hour. At this much low speed of wind the bladeless windmill starts to produce the energy. So the efficiency of this windmill is around 50% higher than the normal windmill.

Main features of bladeless turbine 1. Material selection Current wind turbine technology need to support very different load levels under variable wind speeds, which puts high mechanical demands on Bladeless wind turbines completely eliminates mechanical elements that can suffer wear by friction. so it necessary to choose proper material which can withstand that wind forces and oscillate to produces electricity. For which the vortex of turbine as should be flexible and light weight, the frame should be more effectively rigid .by considering these factors the material is to be selected.

2. Stress & Fatigue This wind turbine is not immune to fatigue and stress forces.Fatigue is defined by the weakening of a material caused due to repeatedly applied loads or forces. Vortex turbine’s rod suffers continuated flexion and a material failure could eventually occur.

3. COST-EFFECTIVENESS

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Bladeless windmill One of the main advantages of bladeless turbines are the low costs associated.this turbines are estimated for levelized cost of energy will be lower, which will allow a faster return on investment. These cost reductions come from a clever design and usage of raw materials.There is no need for a nacelle, support mechanisms, and blades, that are usually costly components in the conventional wind generators

4. GENERATION CAPACITY 5. In wind energy conversion, power generation is proportional to the swept area of the wind turbine. bladeless currently sweeps up as much as 30 % of the working area of a conventional 3-blades-based wind turbine of identical height.As a result, generally speaking we can say bladeless wind power is less power efficient than regular horizontal-axis wind turbines. On the other hand, a smaller swept area allows more bladeless turbines to be installed in the same surface area, compensating the power efficiency with space efficiency in a cheaper way.

6. Atmospheric adaptation In urban environments wind airflows are usually very turbulent, this is an issue for regular wind turbines. In addition, the wake of conventional windmills is problematic when installing several wind turbines working together in the same place On the other hand, conventional wind turbines need an orientation system to face the incident windstream. Vortex wind generators doesn’t need it anymore due to its circular cross section.

Design structure Page 15 PC Polytechnic, Mechanical Department

Bladeless windmill

Fig 3

Components 

Turbine



Rack



Bearing



Base frame



Dynamometer/DC motor



Shaft



spring

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Bladeless windmill

 Turbine: Turbine is the main part of that assembly.It is place on the top of the assembly which is to the shaft . turbine is the oscillating member of project.hence it is necessary the material of the turbine should be light in weight.It is made up of sheet metal.  Rack: Rack is used to convert the oscillating movement of turbine into the rotorymovement of the motor . It is attached to the shaft .

 Bearing There are two footstepbearings used to rotate and support the shaft vertically.

 Base frame Frame is the rigid structure which is attached to the ground surface.All the components of the turbine is mounted on the frame.

 DC motor Is used to convert the linear motion into rotory, which will produces the electricity.

 Shaft Is vertical member on which the turbine is mounted and also the rack is cooncted. Shaft is mounted in the bearing  Spring Spring is used to connect the shaft and turbine.is help turbine to oscillate the turbine.

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Bladeless windmill

components

MOTOR:

    

Speed of motor : 1000 RPM Voltage capacity: 12 V Type of current: DC Output shaft diameter: 6mm Speed of output shaft: 100 RPM

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Bladeless windmill

SPRING:

 Material : Aluminium  Length: 10cm

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Bladeless windmill BEARING:

 Manufacturer:  Inner diameter: 20mm

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Bladeless windmill RACK

 No. of Teeth: 50  Length : 23cm  Material : plastic

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