AC : WIND TURBINE FOR AUTOMOBILES

Transcription

1 AC : WIND TURBINE FOR AUTOMOBILES Sham Tickoo, Purdue University, Calumet (Tech) Sham Tickoo is a professor in the Department of Mechanical Engineering Technology at Purdue University Calumet, USA. He has been teaching CAD/CAM, AutoCAD, Drafting, and Design since His general research interests are in the design and development of wind turbines. He has authored/coauthored several books on CAD like CATIA, NX, Pro/E, SolidWorks, Solid Edge, Autodesk Inventor, 3ds max, ANYS, and AutoCAD. c American Society for Engineering Education, 2011 Page

2 Wind Turbine for Automobiles Prof. Sham Tickoo Purdue University Calumet 2200, 169 th Avenue Hammond, IN CADCIM Technologies 525 Saint Andrews Drive Schererville, IN Introduction When teaching design related courses, the projects, exercises, or assignments that are given in the class room may not challenge the students to come up with innovative ideas. Therefore, it is important to get students involved in challenging team projects, especially the projects that solve some important problems that we are facing as a society. The Wind Turbine (Vertical Axis Wind Turbine) for Automobiles (Figure 1) is one such project that can get the graduate and undergraduate students involved and excited. Figure 1: The Wind Turbine mounted at the top of an automobile The increased use of gasoline for powering automobiles has raised concern for environmental issues such as pollution, global warming, and depletion of ozone layer. Moreover, running the gasoline powered vehicles causes exhaustion of natural resources. As a possible solution to these problems, some companies have introduced electric powered and hybrid vehicles. However, these vehicles also have some limitations or drawbacks due to limited power storage capacity of the batteries. According to some published reports, several automobile companies are working on developing vehicles that will be powered by batteries or hybrid engines and will run miles on a Page

3 single initial charge. And when the batteries run out of charge, the gasoline engine will kick in to run the car and charge the batteries at the same time. However, this will again require gasoline for running the vehicle. As mentioned earlier, the electric powered vehicles can also be used as an alternative to gasoline powered vehicles, but these vehicles also have certain limitations. One of the limitations of these vehicles is that the charge can last for a limited time; after that the batteries need to be recharged. This gives rise to the need of a system that can constantly charge the batteries so that the vehicle runs without any interruption. Keeping all these limitations in view, some companies have designed devices that harness the wind power to generate power to charge the batteries. However, these devices also have some drawbacks and therefore, a lot of research is being done to improvise upon them and come up with new devices to charge the batteries. In continuation to these efforts, the proposed design of the Wind Turbine might help to solve some of these issues. This Wind Turbine will be mounted at the top of the car so that the wind strikes the blades of the turbine, thus generating power that can be used to charge the batteries of an automobile. Initial Concept and Design The Wind Turbine (Vertical Axis Wind Turbine) primarily consists of the Bottom Plate, Top Plate, Top Deflector, Front Deflectors, Side Deflectors, and Rear Deflectors (Figure 2). These components, when assembled, form an enclosure wherein the turbine blades rotate. This design is such that it divides the enclosure in two sections, Left Section and Right Section. The wind that enters into the Right Section of the wind turbine directly hits the blades at high speed and thus causes the rotation of the blades in the counterclockwise direction. The wind that enters the wind turbine in the Left Section is deflected towards the right side and exerts additional pressure on the blades, thus reinforcing the rotation in the counterclockwise direction. Also, the Front Deflectors prevent the wind from entering into the Left Section of the turbine and therefore, the wind entering from the left does not create any resistance to the rotation of the turbine. The Front Deflectors actually deflect the wind at an angle that further pushes the blades in the counterclockwise direction. As a result, the pressure starts building at -20 degrees, thereby increasing the effective power cycle Figure 2: Different components of Wind Turbine Page

4 In addition to the wind entering from the front, the Side Deflectors will also facilitate the entry of wind from the sides of the Wind Turbine. Moreover, the shape of the slots in the side deflectors will guide the wind to enter the turbine in such a way that will increase the pressure on the turbine blades and cause them to rotate faster. Apart from the wind entering the turbine from the front (Figure 3) and the sides, part of the wind moving out of the turbine will also be deflected back into the turbine with the help of the Rear Right and Rear Left deflectors. Consequently, the blades will be pushed, not only from the front and the sides, but also from the back. This will make the blades rotate much faster and more power will be generated.when the car travels, especially at moderate to high speed, the wind will enter the turbine with high kinetic energy from the front in the horizontal direction and strike the blades of the Wind Turbine. This will make the blades rotate at high RPM. In this device, the blades are mounted on the rotor coupled with the generator/alternator through a shaft. The power thus generated will charge the batteries. The proposed device Vertical Axis Wind Turbine overcomes the deficiencies that exist in the devices bearing the US Patent numbers 7,135,786 and 5,920,127. The proposed Wind Turbine will be placed in the horizontal plane and therefore only a small area of the Wind Turbine will be in contact with the flow of the wind. As a result, this device will cause less resistance to the air flow and the amount of drag developed will be significantly less. So, as long as the car moves, its batteries will get continuous supply of power. Advantages of the Wind Turbine Figure 3: Direction of the wind The proposed Wind Turbine has numerous advantages over a conventional turbine. This has been made possible by designing a mechanism that deflects the wind in the desired area of the turbine and over a larger angle. Also, the drag component of the wind force is significantly reduced and the design maximizes the utilization of the wind. Following are some of the key advantages of this Wind Turbine: Page

5 This Wind Turbine is designed in such a way so that the wind can enter and strike the turbine blades from several sides and in different directions. In addition to utilizing the wind that directly enters from the front, the wind will also enter the turbine through the slots on the sides that will further accelerate the blade rotation. The Wind Turbine will continue generating power and charge the batteries even if the car is parked, provided there is sufficient wind to rotate the turbine blades. If more power is needed, the width and length of the turbine blades can be easily increased. Any increase in the turbine blade width will create greater torque and therefore more power. The scaled up version of this Wind Turbine can be mounted under the trucks that have sufficient ground clearance to accommodate it. It can also be used to produce the power for homes by mounting the turbine on a tall structure like a wind mill tower. The design of the turbine makes it possible to mount several turbines on the same structure, thus producing more power economically (Figure 4). Figure 4: Multiple turbines mounted on the same structure The turbine design utilizes the low pressure regions created at the back of a moving automobile to increase the wind speed through the turbine and thus produce more power. The unused power that is accumulated in the batteries can be converted into 110V with an inverter and sold to the utility companies or used at home. The design of this turbine can be easily modified to fit on the sides, front, back, or in the trunk area of an automobile. Like the wind, the flow of water can also be utilized to rotate the turbine. Page

6 The turbine has been designed in a way that drastically reduces the drag component of the wind force and maximizes the utilization of the wind. As the equipment used in this design is inexpensive, the manufacturing cost will be significantly low. The curved shape of the blades in the Wind Turbine helps to increase the impact of wind on the blades. As a result, maximum kinetic energy of the wind is converted into mechanical energy, thus making it much more efficient. The blades are arranged in staggered manner on the rotor. This is to ensure that all blades receive the wind and produce maximum possible energy. The simple design of the device and its parts reduces the need of skilled operators as well as drastically reduces the transportation cost. Moreover, individual components of this device can be easily assembled and their servicing and maintenance is much easier. Fabrication After developing the initial design, the next challenge is to fabricate the turbine within the limited time and resources available in a typical university machine shop. This is when the students get a chance to test their ideas and understand the manufacturability of a product. The material selection and the availability of machining processes in a workshop play an important role in the fabrication. Quite often, it requires changes in the design so that the product can be manufactured at a reasonable cost while maintaining the intent of the design. The fabricated Wind Turbine prototype, mounted at the top of the car, is shown in Figure 5. Figure 5: The Wind Turbine prototype mounted on a car Page

7 Road and Wind Tests To ensure the proper functioning, the turbine was mounted on a car and taken for a road test. Additional tests were conducted in the machine shop, using two high speed leaf blowers. The blowers were arranged in two configurations to determine the effect on the RPM of the turbine. The first configuration is when both the blowers are positioned on the extreme right of the turbine. The configuration 2 is when one blower is positioned on the extreme right and one in front of the deflectors. The results obtained when the leaf blowers were positioned in the first configuration are listed below: Diameter of the Turbine=39 Reading Speed (Km/Hr) Speed of Air (KM/Hr) Turbine RPM Wind Test With Additional Weights To determine the effect of the weight of the turbine blade on the RPM of the turbine, ¼ Pound aluminum circular disks of diameter 0.5 inch were bolted to four alternate turbine blades and then the wind test was conducted. The readings obtained are as follows: Speed (Km/Hr) Speed of Air (Km/Hr) Turbine RPM Page

8 Comments and Conclusion The results obtained from the road test and the wind tests that were done in the machine shop are convincing enough to conclude that this Wind Turbine is a workable product. However, some changes are needed to increase the RPM of the turbine so that it generates sufficient current to charge a battery. One of the changes that is currently being incorporated in the design is mounting the alternator in the lower left corner. A large chain wheel will be mounted on the turbine shaft and a small sprocket on the alternator shaft. The chain wheel and the sprocket will then be connected with a bicycle chain. This arrangement is expected to increase the RPM of the alternator by a factor of 4.25, resulting in about 260 RPM for the alternator. Also, the blades need to be redesigned to increase the width of the turbine blades at the end. This will further increase the force on the blades thereby generating higher RPM. Additionally, a solar panel will be mounted at the top of the Wind Turbine to supplement the power generated by the turbine. It is evident that some drag will be developed in this device, but it will be comparatively less and its special design features will further minimize it. Consequently, this device will produce enough power to charge the batteries. Other tests like CFD (Computational Fluid Dynamics) and Virtual Reality Modeling need to be done to test and demonstrate the functionality of this product. Also, the alternator needs to be redesigned to generate sufficient current at about 150 RPM. In conclusion, the projects like Wind Turbine for automobiles can prove to be quite useful project for students to provide them an opportunity to come up with creative ideas and understand the process involved in product development and manufacturing. If any faculty member is interested in researching and developing this product further, the drawings can be obtained by contacting the authors of this paper. Biographical Information Sham Tickoo is a professor in the Department of Mechanical Engineering Technology at Purdue University Calumet, USA. He has been teaching CAD/CAM, AutoCAD, Drafting, and Design since His general research interests are in the design and development of wind turbines. He has authored/coauthored several books on CAD like CATIA, NX, Pro/E, SolidWorks, Solid Edge, Autodesk Inventor, 3ds max, ANYS, and AutoCAD. CADCIM Technologies publishes quality textbooks in the field of CAD/CAM/CAE, Civil, GIS, Animation, and Computer Applications. They also provide online training and engineering consultancy services. Page