These turbines are useful when wetravel to remote locations where the electrical outlets are not available andare capable of charging our devices anytime. They are also useful when used atlocations such as highways where the artificial air velocity created due tomovement of vehicles on both sides of the turbines is capitalized to rotate theturbines and generate the electricity to lighten up the highways as well as torun the sign-boards.
These turbines produce a poweroutput of 11.85 W at a wind speed of 5 m/s. This power is enough to charge twosmall portable devices or one high power device at a time. This eliminates therequirement of continues power source. The aim of this research paperwas to design a portable MWTs using folding mechanism.
The MWTs are designed byusing the tripod stand folding mechanism and telescopic folding mechanism. Theturbines have an original height of one meter and convert into the total heightof 0.5 meters for transportation.
All parts of the turbines are detachable fromeach other. Hence, the total setup changes into three parts with 0.5-meterslength. VI.
Conclusion The side arms, blades andvertical shaft are detachable from each other. The length of each part is 0.5meters, which makes it compact enough to place inside the rucksack or thetraveling bags. They are handy to carry when traveling by car as they easilyaccommodate in the backside of the car. These wind turbines use tripodstand mechanism for legs and telescopic folding mechanism for side arms. Thetripod stand brings extra stability to the turbines while installation and theside arms grant great variation in the projected area.
B. Portability of wind turbinesThis power generated by theturbines is directly proportional to the wind velocity. Hence, it increaseswith the increase in the wind speed. Itgives a power output of 94.815 W and 320W at a wind speed of 10 m/s and 15m/srespectively.
= 11.85W = 0.5x 1.29 x 0.
5 x 53 x 0.294 = 0.5? A Cp The values of air density (1.29)and power coefficient (0.294) at the sea level have been considered forcalculations.
Now, for designed turbines, if the air is blowing at the speedof 5 m/s, then the power generated bythe turbines is 11.85 watts (W). Cp= Power Coefficient.
10V = wind speed (m/s)A = projected area ( )? = air density (kg/ ) = power (W)Where, = 0.5? A CpPower is also an important factorfor the designed turbines. They must be powerful enough to charge the devices.The electric power generated by VAWTs is calculated by using the followingformula.A. Power calculationsV. Results Figure 7: design of micro VAWT * The movement of the blades resultinto rotation of the vertical shaft that generates electricity. The electricitygenerated is stored in the batteries.
Two charging outlets of 5 W capacity andone charging outlet of 10W capacity are placed at the bottom of the verticalshaft. This increases the ease of connecting devices to the turbines forcharging.The micro VAWTs with acombination of a telescopic mechanism and a tripod stand mechanism, asdiscussed above, is shown in figure 7. It consists of three symmetricallyarranged Darrieus airfoils. They are mounted on the telescopic side arms, whichare flexible in length.
The battery and the generator are situated inside thevertical shaft, and the power outlets are provided at the bottom part of thevertical shaft. The vertical shaft is circular in shape, which helps inaccommodation of the battery and generator. IV. Design Figure 6: Tripod stand mechanism, (SIRUI T2204X4-Section Al (2)) 8Selecting a tripod stand mechanism improves the stability of the MicroVAWT. And it is also helpful in accommodating the vertical shaft. Moreover, itsimplifies the location of charging outlets. The side arms and blades are madedetachable from the vertical shaft to make it convenient to carry.4) Tripod stand mechanismFigure 5: Telescopic mechanism, (ESTOConnectors) 3 In case of Darrieus VAWT, the blades are mounted on the Vertical shaftwith the help of a side arms.
To make it portable during transport, reducingthe length of side arms is necessary. The telescopic mechanism is used toadjust the length of the arms. Also, it provides us with the flexibility of thecross-section area of the wind turbine. 3) Telescopic folding mechanismAfter observing these available portable WTs,the combination of the folding mechanisms (telescopic mechanism, tripod stand mechanism)is selected.”Poweroutput obviously varies depending on wind-speed, but the turbine can reportedlyproduce a constant output of 5 watts if the wind is blowing at 18 km/h (11mph).” 6Figure 4: Nil’s Ferber Foldingturbine.
(Folding turbine makes smartphone charging in the wild breeze ) 6 Nils Ferber has built this turbine as the project for his Master’scourse of product design at the Ecole Cantonale d’art Lausanne (ECAL). Itweighs 1 kg. The umbrella folding mechanism is used to make the Savonius bladesportable. The turbine installed by pulling on the telescopic shaft based ontension and compression.
It is secured with the help of guide ropes.2) Nils Ferber’s folding WTs for charging smartphones.figure 3: Trinityturbine 1 Itholds a 15W generator and a 15,000 mAh battery inside the vertical shaft. Ithas a weight of about 1.8 kg. The use of tripod stand mechanism helps to reducethe height of Trinity wind turbine to 12″ from a total height of 23″. 2Skajaquoda has designed the Trinity wind turbine.
It consists of legsand three blades made up of aluminum and plastic. Trinity uses tripod standfolding mechanism for legs to make it portable. It is basically a Savonius windturbine.
1) The Trinity wind turbinesThe folding mechanism plays avital role to make VAWT portable. The folding mechanisms used in existingportable WTs are studied. They are as follows:C. Selection of folding mechanisms The available portable WTs are Savonius WTs.Instead of having high start-up velocity, Darrieus WTs have better efficiencythan that of Savonius WTs. Darrieus WT is the one which should be taken intoconsideration. Hence Darrieus WT is selected.Figure 2:Darrieus wind turbine 4 This turbine consists of two or three bladesmounted on the rotating shaft or framework.
This arrangement is equally useful,no matter in which direction wind is blowing. It is a lift type device, and theblades are always symmetrically arranged. Their efficiency is more than that ofthe Savonius wind turbines.2) Darrieus wind turbinesFigure 1:Savonius Wind Turbines R 7 Theseblades are used to convert the force of the wind into torque on a rotatingshaft. The turbine consists of many airfoils, but not always vertically mountedon a rotating shaft or framework. It is one of the simplest turbines.Aerodynamically, it is a drag type device which consists of two or threescoops, ‘S’ shape in cross-section.
These turbines are used whenever cost orreliability is much more important than efficiency.1) Savonius wind turbinesDependingon the types of blades, there are two primary types of VAWTs: drag-type(Savonius) and lift-type (Darrieus). A drag-type turbine performs better at theinitial start-up wind speed and lift-type turbines have higher efficiency.B.
Selection of the blade type The objective is to generate a small amountof power, and the turbine should be portable enough to carry. Hence the microVAWT is selected for the desired goal. MWTs have less cost of installation comparedto other renewable energy resources and are used in places where theelectricity is not available. 5 “According to the IEC 61400-2 standard of theInternational Electrotechnical Commission (IEC), WTs are again divided into twoclasses: small WTs (SWTs), having a rotor-swept area of 200 m2 orless, and large WTs (LWTs), with a rotor-swept area larger than 200 m2.According to the Small and Medium Wind UK Market Report 2013, commerciallymanufactured SWTs are analyzed in three classes: micro WTs (MWTs), SWTs, andsmall-medium WTs (SMWTs).” 5 HAWT VAWT 1) The axis of rotation is parallel to the direction of wind flow.
1) The axis of rotation is perpendicular to the direction of wind flow. 2) Air strikes from one direction. 2) Air strikes from all directions.
3) Gearbox cannot be placed on the ground. 3) Gearbox can be placed on the ground. 4) The tower is essential; hence the cost of erecting is high. 4) The tower is not essential, hence reducing the cost of erection. 5) A yaw mechanism is required.
5) A yaw mechanism is not required. 6) Control system is required. 6) Control system is not required, hence reducing the cost of frequent maintenance.
Table1: Difference between HAWTs and VAWTs * Wind turbines are divided into two main types: Horizontal Axis WindTurbines (HAWTs) and Vertical Axis Wind Turbines (VAWTs). They are used allover the world for high-scale and low-scale power generation.A. Types of turbines III. Design of wind turbines The first step is to become familiar with different types of windturbines, blades and then select the best.
The primary focus is on the foldingmechanism. This research paper considers the existing folding mechanisms, to makethe wind turbine portable.The objective of this research is to make useof wind turbines as a never-ending source of energy to charge portable devices.To achieve this goal,folding mechanisms are selected to make it portable to carry and powerfulenough to charge the devices.II.
Methodology To charge portable devices, these WTs should become portable otherwiseit is difficult to carry them. This paper intends to research on a foldingmechanism for WTs to make them easy to carry and to provide a clean andunlimited source of power for different portable devices. Chapter threedescribes the process of selecting the type of turbines, blades and foldingmechanisms for the proposed wind turbines. Results and calculations are discussedin the later part of the paper. Wind turbines (WTs) are a cleanand unlimited source of energy. However, most of the innovations in wind energyhave been intended to produce power on a large scale. Those devices areenormous and are not useful in charging portable devices. One step closer tothe wind energy leads to the use of micro wind turbines(MWTs) to charge thesedevices using the unlimited power of the wind.
2Batteries are the primary power source ofthese devices; their capacity is one of the limiting factors. They depend on electrical outlets to power them. Mostelectrical outlets are stationary, which reduce their availability andflexibility while charging.
9Energy is input to drive and improve the life of human beings. Theconsumption of energy is directly proportional to the progress of humanity invarious forms. Nowadays, many people are using portable electronic deviceswhich are accessible and technologically advanced; hence humans have become addicted to them. They all needthe energy to run.
With our increasing dependency ontechnology and portable devices, it is impossible to keep charging thesedevices.I. Introduction Humans are using a variety of renewablesources of energy for a long time.
But, the power generation using thesesources is done on a large scale and the devices used for this purpose are hugein size. They are not available for small power generation. Today, the use ofportable devices has increased to a large extent and have become an inseparablepart of daily life. They work on electricity and must be charged whenever theyrun out of charging. Considering their daily use, they need charging every nowand then as their power source i.e.
batteries have low capacity. Wind is anunlimited source of energy and is one of the solutions to this problem. Themicro wind turbines (MWTs), are small in size and generates a small amount ofenergy. This paper works toward making the MWTs portable. These turbines aremade convenient to carry using folding mechanisms to charge the devices. Theside arms and stand are made compact using a telescopic and tripod standfolding mechanism respectively.
The designed turbines generate an electricaloutput of 11.85 watts when the wind is blowing at a velocity of 5 m/s, whichincreases with increase in wind velocity. The whole wind turbine converts intothree different parts of 0.5 meters length each for transportation and are easyto install. They are capable of charging two small portable devices at a time.This eliminates the need for an unlimited source of power to charge the devicesirrespective of the time and place.Abstract Dhiraj Umaji Devardekar South Westphalia University of Applied Sciences 10062192 [email protected] Folding Mechanism for Micro Wind Turbines