CO2 Dragster
Conceptual Model
Identify the problem: Designing and building the quickest and most aerodynamic CO2 dragster possible.
Generating Ideas:
- Brainstorming Notes:
- Relevant and non-relevant thoughts: I think that having a spoiler will be good in making the car more aerodynamic.
I think that the dipped and pointy front end of the car will also be good for aerodynamics. I'm still not sure on whether to go with four wheels or three wheels.
- Ideas that focus on a specific part of the problem:
Constraints:
Generating Ideas:
- Brainstorming Notes:
- Spoilers
- Round edges all-around
- Dipped front end
- 4-wheels
- Relevant and non-relevant thoughts: I think that having a spoiler will be good in making the car more aerodynamic.
I think that the dipped and pointy front end of the car will also be good for aerodynamics. I'm still not sure on whether to go with four wheels or three wheels.
- Ideas that focus on a specific part of the problem:
- Sanding the final product down to the highest grit to make it as smooth as possible; helps with reducing drag
Constraints:
Criteria:
- Body Shape (smoothness for best speed)
- Speed
- Aerodynamics (least drag)
- Weight (lightest weight)
- Stability (won't turn, all weight is even and goes straight)
Research:
- Theoretical: Spoilers on cars help to stop the wheels from lifting up when going at high speeds. There are many factors that come into play when building a CO2 dragster, and you want to have the least amount of mass, drag, and friction.
Documentation:
George, Patrick E.. "How Aerodynamics Work" 17 March 2009. HowStuffWorks.com. <http://auto.howstuffworks.com/fuel-efficiency/fuel-economy/aerodynamics.htm> 29 April 2015.
George, Patrick E.. "How CO2-powered Dragsters Work" 22 March 2011. HowStuffWorks.com. <http://auto.howstuffworks.com/auto-racing/motorsports/co2-powered-dragster.htm> 29 April 2015.
- Empirical: There has been no empirical research done yet.
Possible Solutions/Sketch:
- Torpedo
- Dragster
Idea matrix:
Summary: I chose the dragster because it scored best on the idea matrix and because based on the research that I gathered and personal thoughts, it should turn out to work very well.
- Body Shape (smoothness for best speed)
- Speed
- Aerodynamics (least drag)
- Weight (lightest weight)
- Stability (won't turn, all weight is even and goes straight)
Research:
- Theoretical: Spoilers on cars help to stop the wheels from lifting up when going at high speeds. There are many factors that come into play when building a CO2 dragster, and you want to have the least amount of mass, drag, and friction.
Documentation:
George, Patrick E.. "How Aerodynamics Work" 17 March 2009. HowStuffWorks.com. <http://auto.howstuffworks.com/fuel-efficiency/fuel-economy/aerodynamics.htm> 29 April 2015.
George, Patrick E.. "How CO2-powered Dragsters Work" 22 March 2011. HowStuffWorks.com. <http://auto.howstuffworks.com/auto-racing/motorsports/co2-powered-dragster.htm> 29 April 2015.
- Empirical: There has been no empirical research done yet.
Possible Solutions/Sketch:
- Torpedo
- Dragster
Idea matrix:
Summary: I chose the dragster because it scored best on the idea matrix and because based on the research that I gathered and personal thoughts, it should turn out to work very well.
Graphical Model
Working Model
The Beginning
Just the starting piece of balsa wood that we were given.
Just the starting piece of balsa wood that we were given.
The Transformation
After finishing my graphical model, I sketched out the measurements on a sheet of paper, and then put that paper on both sides of the original piece, and drew around the dragster to mark where I would cut through. I also drew perpendicular lines to mark where I would drew my axle holes, which was the first thing that I did when I worked with the equipment. After drilling my axle holes, I used the band saw to cut through where I had made the marks (also made sure to apply relief cuts) to get my rough overall dragster. I didn't get it perfect, and used both the flat and round sanding equipment to get it to what I wanted it to look like. From there, I moved on to hand sanding. Moving up from the smallest grit up, I tediously made my CO2 dragster as smooth as possible.
After finishing my graphical model, I sketched out the measurements on a sheet of paper, and then put that paper on both sides of the original piece, and drew around the dragster to mark where I would cut through. I also drew perpendicular lines to mark where I would drew my axle holes, which was the first thing that I did when I worked with the equipment. After drilling my axle holes, I used the band saw to cut through where I had made the marks (also made sure to apply relief cuts) to get my rough overall dragster. I didn't get it perfect, and used both the flat and round sanding equipment to get it to what I wanted it to look like. From there, I moved on to hand sanding. Moving up from the smallest grit up, I tediously made my CO2 dragster as smooth as possible.
Finalizing the product
After sandpapering the dragster to the highest grit, I painted it with one coat of red, let it dry, and then applied another red coat. Once that dried up, I repeated the process with the black dash. After all the painting was done, I put the axle through the axle holes, popped the wheels on, screwed in my fishing line holes, and finished my CO2 dragster. Check it out in action :)
After sandpapering the dragster to the highest grit, I painted it with one coat of red, let it dry, and then applied another red coat. Once that dried up, I repeated the process with the black dash. After all the painting was done, I put the axle through the axle holes, popped the wheels on, screwed in my fishing line holes, and finished my CO2 dragster. Check it out in action :)
Mathematical Model
Using measurement and time trail data, I made a mathematical model of what feature the fastest cars had. According to my graphs, the fastest car would have as follows: Shortest body lengths, larger body heights with wheels, least amount of weight, body width at axles (front and back) shortest widths, largest widths (including wheels), largest distance between bottom of axles hole to bottom of car, shortest distance from rear of car to rear axle hole, longest distance at Wheelbase (axle distance apart at farthest points), and shortest distance between the Lowest point of CO2 chamber diameter to race surface (with wheels). Personally, I think that weight was the most important factor in deciding times. Less weight = better times.
Body length: This graph shows that shorter body lengths generally meant shorter times.
Body Height with Wheels: This graph shoes that generally larger body heights meant shorter times. Complete Car Body Mass: This graph shows that generally less weight meant shorter times. Body Width at Axles (front and back): This graph shows that smaller body widths at axles meant faster times. Vehicle Total Widths (including wheels): This graph shows that larger widths meant better times. Bottom of axles hole to bottom of car: This Graph shows that generally larger distances between the bottom of axle holes to the bottom of the car means faster times. Distance from front of car to front axle hole: Shorter distances mean shorter times, although there is a very insignificant difference in this category. Distance from rear of car to rear axle hole: This graph shows that shorter distances meant shorter times. Wheelbase (axle distance apart at farthest points): This graph shows that longer distances meant shorter times. Lowest point of CO2 chamber diameter to race surface (with wheels): This graph shows that shorter distances meant shorter times. |