This project focused on the concepts of aerodynamics. We learned how to use wind tunnels to help us calculate the drag of two airfoils and our CO2 car. We designed our car by keeping in mind the factors of aerodynamics that would possibly help or prevent our car from having a high speed when it was in action. We built our car using pine, wheels, and rods to connect the wheels. We designed the shape of our car to have two bumps and a small, pinched front end. By streamlining our design, we hoped that drag would be reduced as much as possible, allowing the car to move fast.
Technological Concepts
The technological concepts of aerodynamics were related to this project. We had to make sure that when a thrust- a push suddenly or violently in a direction- was applied from the puncturing of a CO2 cartridge, our car would travel fast along the fishing line. We tried to reduce the amount of drag, that would work against our car, as much as possible.
Learning Goals
Our goals in this project were to figure out the best design for a CO2-powered car that would allow it to travel as fast as possible. We had to learn which designs worked best by testing everyone's different models. I was wondering how the slightest differences in shape would affect the cars' performances. Also, I hoped to better understand how drag will be affected by the shape of a car, including pointed tips, curved tops, and more.
Description of Project:
Our car had a pretty basic design in the way that it was not shaped in an abnormal way, but we did include a bump in its front and then a curve that rose towards the back. We figured the air would be able to accelerate down the bump and then rush up the ramp. At first, the car we made was pretty big and heavy, and its race time was slow- about 3.5 seconds. We decided to sandit down a ton in order to make it smaller and lighter, and that really improved its performance- its final time was 2.9 seconds.
Positive Feedback
The best thing about our car was that it was the result of our problem solving. We built the car, tested it, and realized that it moved extremely slowly because of its large mass. We decided to sand as much as we could, and helped the car to have a reduced mass, a lower time, and a greater speed. Although our design seemed simple, it performed pretty well. I was quite relieved that our car's performance matched up very closely with that of the other cars, because they had such different, rounder, and smaller designs.
Redesign Paragraph
If I were to do this project over again, I would try to make the car even smaller. My partner and I tried to follow the size requirements in the first place, but our car was still much bigger than everyone else's. If we had built it to be smaller, it could have gone faster. Also, I would like to try to make a more different design for the car and see how that fares, compared to the original design. This probably would include a pointed tip and maybe a hollowed-out section.
Technological Resources
We used tools like the drill press, hand saw, and sander to make our car. We had never used the hand saw before, and it really helped us to shape our car the way we wanted while we cut it out of the wood block. In addition, the sander was our savior when we made our car smaller and lighter. It shaved down a great deal of mass.
Biggest Challenge
The biggest challenge about this project was following the size requirements while also making our car fast enough compared to others. There were length and weight requirements and we also had to be smart about the shape of the car. Our car was much bigger than the other groups', but once we shaved it down, its speed compared closely to those of the other cars.
What I Learned From This Project
I learned that when you want something to have speed, design is important, but mass may be even more important. A wooden car will not roll speedily if it is really heavy. Now we know that we must always take size into account when working on projects. Also, I learned about the many different concepts of aerodynamics and how they affect airfoils.
