This engineering project was about a variety of elements that pertain to a “home- made” turbine. The mall purpose of the turbine project was to design and construct a turbine using material around the lab, while maintaining the project requirements. The turbine was to be completed in one week, where it would be ready to be tested for power, stiffness, and weight. Everyone in the group would have to work together to make sure the turbine would be completed on time. In addition to the turbine structure, a motor blade Is needed with ample efficiency to produce power.
The design of the blade was done using the Inventor Program 201 2 and the blade was made by the lab assistant. Overall, the final product had to withstand the force of a 25 MPH gust wind, while still outputting an efficient amount of RPM to light up 7 light bulbs, and having the least amount of displacement as possible. The project seemed very exciting to the group at first. The team was eager to get started on the design of the turbine structure, while of course keeping in mind the guidelines that were stated.
Initially they thought of Just using balsa wood for the entire structure, but after having a discussion, the team decided to be more unique and use a more hollow substance. The team then realized that Principles Cans were the perfect balance between light and stiffness because of the hollow interior and perfect cylinder shape which made a good center for the structure. The team used one full Principles can and about h of another can, which added up to exactly 17. 03 inches when stacked on top of each other.
The full Principles can was mounted to the base board using hot glue. Then, we hot glued the smaller can on top of the full can. To top It off, we hot glued the top board on the smaller can and screwed two hooks on the bottom of the small board. The team used only the tools that were provided in the lab to build the structure. Most of the materials were bought outside of the lab. The materials consisted of two Principles cans, four pieces of fishing wire, and eight hooks, In addition to the bottom and top boards, the blade, and the motor.
Putting their engineering minds to work, they all put their input on how the structure would come about and the different techniques on how to make the design of the structure. Figure 1: The front view of the fleshed turbine product The final product was exactly 17. 03 inches tall and weighed 345 grams. There were a total of 1 8 elements (materials that was used to build the structure and keep It stiff. The peak power output was 1 1. 4 mm and occurred during the 4th light bulb load. During the peak power output the speed of the blade was about 4900 RPM.
This mm from the fan to the blade. In addition to the power output, the final displacement was 0. 43 mm with a 1. 20 Keg (1 1 . 768 N) weight with the stiffness of the structure being 27. 775 warn. Overall the team had mixed feeling about the results of our wind turbine. The team was happy with the design and stiffness (displacement) of our structure which was one of the stiffest compared to the rest of the groups in the lab section. Although, the team was not very pleased with our power output, compared to the other groups in our lab section.
The power was not as the team expected, mainly because the team obtained a random turbine blade due to poor embossing. The learning experience was very positive. The team experienced a lot of “do’s and don’t” on making a wind turbine. The team recommends for future projects to make sure to emboss their turbine blade correctly, in order to receive the correct blade for testing. In addition, the team recommends testing the turbine power output several times before the final testing lab day occurs.
In conclusion the team had a very enjoyable time designing and constructing the turbine structure and blade. Introduction General Objectives Two major goals were to be achieved by the end of the wind turbine project. The most important goal was to design and construct a wind turbine that would allow students to gain more knowledge about the engineering principles involved. Some of those principles include designing and fabricating the turbine rotor blades and the support tower, calculating the power output of the turbine, and measuring the stiffness of the support tower.
The other chief goal was to build oral presentation and communication skills because they are an essential tool in becoming a successful engineer. Specific Objectives Learning How to Design with Solid Modeling Software Three-dimensional computer-aided design was a new concept for most people in the group. So, in order to become more familiarized with the program Inventor 2008, dents were instructed to go through several tutorials to learn about the different tools in the program. When the group was able to use these tools, the designing process for the turbine rotor blades began.
Designing and Fabricating the Turbine Rotor Blades From experience on Inventor 2012 and previous research on wind turbines, the group was to design and have the turbine rotor blades fabricated. The group number of blades, blade shape, and angle of attack were all major factors that the group decided on. The group determined that the turbine should have three blades because it was the most cost efficient. The blade shape and angle of attack were Just based off the example given in the Powering because it was thought that the efficiency was already at a good level.
The goal was to design a blade that would be able to spin at high rams and generate plenty of energy. Figure 2: Finished Wind Turbine Blade Design Designing and Fabricating the Wind Turbine Support Tower Every group of students was given a base and an upper support plate where the motor would be placed. Everything in between needed to be designed by the teams as the support for their wind turbines. It was decided that a Principles can be used on count of its stiffness. From the Ole lecture, the professor had shown a slide where it said that hollow structures tend to be stiffer.
The structure needed to be as close to 17 inches tall as possible. The group ended up using two Principles cans adhered together to meet this requirement. The goal was to build a support structure that was lightweight, stiff, and cost-efficient. Performance Testing of the Wind Turbine and Tower All students needed to weigh their structures, measure its height, and demonstrate the power output from the turbines and stiffness of the support structure. The goal of the group was to perform well in all the categories.
Although, the group put lightweight over all the other categories because it was thought that it would make it stand out. The structure needed to be lightweight, be 17 inches high, generate good amounts of energy, and be able to withstand a 25 MPH wind with minimal structural displacement. Presentation In a 5 to 10 minute presentation, every group had to explain their findings during their experience with the wind turbine project. The group wanted to score well on every part of the grading rubric and bring a well-developed and cohesive oral reservation.
To do this, a different part or aspect of the presentation was assigned to one member of the group. Each member had to know everything about the project but more importantly become an expert at his part of the presentation. The goal was to build presentation and communication skills. Support Structure and Stiffness From the experiment instructions, it was said to create a structure that can be lightweight, stiff, and effective in supporting the wind turbine blade and motor that height would include the lower support plate, the upper support plate, and the support structure itself.
Figure 3: The guidelines to makes the support structure. The goals that the team had to accomplish were, finding materials that were light, and stiff, and necessary. With these goals to follow the team had to make a structure that overall was light, no taller than The materials that were used in the development of the support structure were Principles cans, eye hooks, fishing line, and balsa wood. The Principles cans were used as the main support structure. Fishing line and the balsa wood were used to keep the Principles cans in place when the structure faced high winds.
Figure 4 and 5: The support structure of the wind turbine. From the pictures above you can see the design of the support structure. The team chose to use Principles cans because of its stiffness capabilities. Based on what was taught in the lectures, hallow structures have less weight and are more stiff then structures that are not hallow. Pricing cans seem to be the most reasonable object to use because of its abundance around campus and its stiffness. The structure used one full Principles can as well as h of another. Fishing line was used to help keep the part of the structure in place when high winds occur.
Because the slope of the stiffness line was very low we can say that the stiffness of the structure was pretty stiff. Turbine Blade Design Blade Type and Design Limitations The program Inventor 2012 was used to design the blades of the turbine. The limitations of the blade in this project were the diameter of the swept area, the blade thickness, and the type of blade to be designed. The diameter of the swept area cannot exceed 152. 4 mm and the blade thickness could not exceed 6. 35 mm. This project required the blade to operate on a horizontal axis with a lift design.
A horizontal type axis means that the turbine blades will be rotated along the x-axis, which should be parallel to the ground. A blade with a lift design is an airfoil blade animal to that of the wings of an airplane. The wind hitting the blades is split, causing a difference in wind speed pressure. The air pressure at the top of the blade is lower, so the pressure beneath the blade will push upward, lifting the blade. Creating the Blade Using the hub file provided, Inventor 2012 was opened so that the blade design can be started. After the hub was fully loaded, the next step was to display the Y-Z plane.
Once this plane is visible, an offset plane can be created 6. 25 mm away. To create a better working environment, we projected the geometry of the hub and suppressed its features as shown in Figure 8. Figure 8: The projected geometry of the hub Now that the work environment is set, a vertical line needs to be drawn at the midpoint of the projected geometry, which is on the offset work plane that was previously created. Two lines need to be drawn parallel to the vertical midpoint line. The first line will be 9 mm to the left of the midpoint, and the second will be the same distance away, but in the opposite direction.
The sketch should now look like two small rectangles as shown in Figure 9. Imagining the two rectangles as one large rectangle, a diagonal line needs to drawn from one corner of the rectangle to the opposite corner. This will serve as the bottom of turbine blade. Figure 9: What the offset plane should look like after drawing the two vertical lines mm apart from the midpoint. To create the rounded curve of the turbine blade, the spine command needs to end of the diagonal line, and the third point will be the opposite end of the diagonal line. The second point is the point that determines the curvature of the turbine blade.
The profile of this plane is now constructed, so the three vertical lines can now be deleted. A new offset plane needs to be created. This new offset plane will be 63. Mm away from the previously finished plane. From the midpoint on the bottom line of the plane, a 9 mm line needs to be constructed. Create a spine starting at the start of the 9 mm line to the end of the same line. The tip of the turbine blade is now constructed. Now that the two blade profiles are completed, the loft command needs to be used. This will form the shape of the blade. The hub now needs to be brought back, so we need to unsuppressed its features.
Filleting the blade is now necessary in three places. The first is the thicker side of the blade. This side needs to be filleted by 0. 3 mm. The second place is the thinner side of the blade, and the final place is the bottom of the larger end of the blade where it meets with the hub as depicted in Figure 10. These two positions need to be filleted by 0. 15 mm and 0. 3 mm respectively. Figure 10: A clear view of the final area to fillet. The single blade is now complete and needs to be replicated. This is done by selecting the circular pattern icon and clicking on the blade.
A window will pop up and the rotation axis needs to be set to the center of the hub. Once this is complete, the number of parts needs to be set to 3 with a degree of 360. This will create 3 blades and evenly distribute them in a circle around the hub. The turbine blades are now complete. Testing the Turbine Blades To test how well the turbine generates power, we connected the blades through the hub to a small motor. The motor was connected too power meter, which was connected too load box. Using this set up, a wind of 25 MPH from a large fan will blow against the blades and generate power.
The power generated will be calculated and displayed in militants on the power meter along with the voltage in volts and current in milliamp. From the power meter, the power will flow into the dad box and light up small light bulbs. Figure 11: Top view of the power meter. Switch Input connection Figure 12: Basic depiction of the load box. Once the location has been set, the wind turbine needs to be moved there. The distance from the fan and turbine blades is then measured. To calculate the speed of the turbine, a tachometer is needed. Obtain reflective tape and stick it to one of the turbine blades close to the hub.
The tachometer is then used to determine the blade speed in RPM, or revolutions per minute. Before running the test, the load box needs to be set. The load box consists of even small light bulbs that use the power generated from the wind turbine to light up. At least one light bulb switch needs to be on before the fan is started and data is collected. After a stable turbine speed is obtained, the voltage, current, power, and RPM is recorded. An additional light bulb switch is then flipped on and data is collected again once the turbine speed becomes stable again.
All of the tools were provided to the students in class by the professor. The first thing the group did was design the blade for the wind turbine using the program Inventor 2012. This program allowed the team to create a unique three blade turbine specified to the team’s liking. Once the design process for the blade was finished, the ext task was to design the support structure for the wind turbine. Using two Principles cans, some hot glue, fishing-line, some nuts and bolts, and wood, the team built the structure from scratch.
There was a lot of guessing and checking involved with this process because the team thought the structure was not sturdy enough. At the end of this debacle, sturdiness was achieved with minimal weight. When the testing of power and stiffness occurred, the wind turbine did not perform as well as it should have. It generated less than average power, but the stiffness was decent when comparing it to how little the structure weighed. What was Learned The team learned that when attempting to design the blades for the turbine, the embodiments of the team number and section should be clearly seen and done right.
In the testing process, the blade that the team designed could not be used because there was no clear evidence of it being anybody blade. Another thing the team learned was to research more on the structural designs of real turbines. The team’s focus was on making the structure as light as possible. The Pricing can’s lightness did not do much for the wind turbine’s performance because the turbine did not generate a large amount of power compared to other groups. Even if the turbine generated the most energy it was not even the lightest one out there.
Outcomes of the Project Being able to work as a team was very helpful for every member of the group. It using fishing-line for extra support. Although the team did not actually achieve the goal of creating the lightest wind turbine, the fact that a finished product was produced was consolation. The group’s communication was excellent throughout the whole process and several meetings were held out come class to insure that everything was handled correctly. The only thing that did not work out the way as planned is trying to be creative with the project. Because of time constraints, the team decided function was more important than appearance.