Ryan Sauer 10/26/15 Aerospace Engineering
Glider design
We entered how the parts of the plane are shaped, where different things are placed on the plane, and how much mass is on the nose of the plane. We had different constraints we had to use when we put our glider into AERY, so we could not make it gigantic or make it have a big nose mass. We made the measurements non decimals so it would be easy to construct the model glider.
Benefits of computer based models
The AERY software provides information on how your plane will fly, and if it does not fly it tells you what to change to make it fly. This info is very helpful when trying to build a glider because instead of building and testing it you can out all the information into AERY and it will tell you how good it flies or what can be improved. Some of these calculations that AERY provides are center of gravity, neutral point location, estimated mass, throwing velocity, flight angle of attack, estimated glide angle, estimated stall velocity and estimated stall angle. These could be calculated using formulas, but using AERY is much faster and easier. The picture below shows different info AERY gives you like the center of gravity and neutral point location.
Build pictures
Glider contruction
To construct a glider follow the measurements AERY gave you very strictly to make it fly how it is supposed to. Make sure you use the right measurements and measure more then once before you cut. Make sure you place the wing, horizontal stabilizer, and vertical stabilizer in the correct position and make sure it is centered on the fuselage. If you do not do all of these your glider will not fly how AERY said it would, so in most cases it will fly worse.
Final glider picture
flight Videos
erin and ryan flight data
Conclusion questions
- Explain which glider or aircraft term were difficult to understand and the correct definition. Root Chord- Part of an airplane wing, side of wing attached to fuselage Taper Ratio- Used to approximate elliptical span wise load distribution
- Explain any challenges if someone else were to construct your design using the AERY print. If someone tried to construct our design they would have to be very precise to calculate angles and ratios
- Explain any challenges faced using the AERY software and how you overcame those challenges. One of the major challenges with the software was that it long for us to get the software up and running. Another problem was the instructions given about why the plane wouldn't fly were vague, which meant we had to mess with the numbers until the plane could fly.
- Explain difficulties faced with this second design challenge compared with the first challenge. Because we had to refine the design for the second time, we had to be more precise. The first time, all we had to do was get the plane to fly, but the second challenge wanted me to refine and improve my original design. So we had to experimentally change parts without changing the whole design concept.
- Explain how these constraints impacted your glider design compared to the first. The 2nd glider design was more efficient/effective. The plane flew better (more stable) the second time compared to the first. This means it had better pitch and directional stability.
- Funding for a new project is always limited in some way. How does the proposal process ensure that the idea being proposed will satisfy the project requirements? The proposal process allows someone to share their ideas and test if they would work, and if it did not work they are allowed to fix it to the constraints given. Plus a project is more likely to be funded if it meets all project requirements. They are also more competitive, one would want their idea to be the best it can be so it has a better chance of being selected.
- Projects fail not due to a lack of solid designs but instead due to other issues. Describe these issues and explain how the proposal process ensures that the design with the highest likelihood of success can be selected. Some issues include lack of money, lack of planning, lack of resources etc. The proposal process creates competition and allows different designs to be compared, and the one with the least amount of issues wins/gets accepted.
- Describe the most persuasive elements of your proposal. The most persuasive elements of my proposal are the high evaluation number (140) that proves it will fly if constructed correctly. Our plane is also very easy and fast to construct.
- Explain why someone would have either a positive or negative impression after reading through your proposal for the first time. Someone would have a positive impression after reading through our proposal because they would see how easy it is to construct and that it will be able to fly when built properly.
- Was the glider as stable as you expected? Why or why not might this be so? Yes, the glider was just as stable as expected. This is because we built the glider to the exact constraints as shown using the AERY software. We built the glider to be balanced on all sides, and so it flew balanced.
- What techniques did you use to “trim” the glider for straight and gently descending flight? We used clay to act as an extra weight on whatever part of the glider needed to be balanced. For example, to make the glider gently descend, we had to add some clay to the nose of the glider to give it a little more weight. We also sanded some edges off to make it more aerodynamic.
- How many test flights were required to get the glider trimmed for long distance, straight-line flight? Was this expected? Why or why not? About 12 test flights were required to get the glider trimmed. This was expected because we had to test it originally, and then test the glider after each alteration was made, to figure out if the change helped or harmed the flight of the glider.
- Explain the strengths and weaknesses of a competitive trial as a method to identify an optimal design. The strengths of a competitive trial include being able to see what design flies the best, is most durable etc. The weaknesses include not being able to conduct a fair competition, because of all the diversity in designs, as well as not being able to compare all the strengths and weaknesses of each design.
- Explain differences between your glider’s performance through flight-testing that was unexpected based on the AERY software predicted flight characteristic. Our glider's performance during flight-testing was a lot better than what was predicted through AERY software. Our glider flew a lot better than most other gliders from our class, despite the fact that our AERY evaluation number was a lot lower than the other gliders built. For example, the glider we designed had an evaluation number of 140 and flew 50 ft. Another glider had an evaluation number of 230 but only flew 38 ft.
- Based on the entire flight test data, from every group, explain conclusion that you can make about optimal glider designs for long distance flight. An optimal glider design, for long distance flight, needs to be balanced on all sides, with a lot of surface area exposed for the wings. The wings should be curved to be more aerodynamic and to decrease friction and drag. The glider itself should be larger in size, without weighing a lot. This ensures the glider will be stable enough during flight and also that it can withstand the forces of drag and weight to travel a long distance.