User:Kylekmcd8/enes100/hovercraft

Write problem/project Goal
My goal would be take a previous design for a successful hovercraft and make it more efficient. With the help of our instructor, we made a test that our hovercraft design is going to have to pass. So it will be a measurable quantity that later groups can see and judge how efficient our design is compared to others. Therefore it is okay if our hovercraft design does not pass our test.

My First Task
To start out, I looked at what other groups, that have worked on this project, have achieved. I learned that many groups struggled with the propulsion of the hovercraft, while a few carelessly started building prototypes without knowing how they worked.

I also researched online to figure out the background of hovercrafts in general and how they work. I found this website to be very useful: http://ap-physics-b-project.wikispaces.com/Aerodynamics+of+Hovercraft+-+Horowitz+&+Lopez. I found that the physics required for a hovercraft to be understood involve air pressure, lift, propulsion, volume, and friction. This website goes into detail explaining each one. It contains a hovercraft lift calculator, a formula to calculate air pressure (P=F/A, P being air pressure, F being force of weight, and A being area of the hovercraft). It is important that there is the right amount of air pressure, because if there is too much then the craft could tip over. And once there is the right amount of lift, there should be no contact with the ground at all causing no friction force to occur. All of these aspects of physics are quite necessary for a hovercraft to function properly.

Summary of actual work over first weekend
It was suggested to our group to measure the efficiency of our hovercraft design by calculating the masses of each object and the power each design puts out. We used a triple beam balance and started weighing parts of the old design and our new hovercraft design, but seeing how we have not finished our new design yet, we do not have a complete table of mass values for the efficiency test.



Week1 Narrative
Now that we know more about hovercrafts and what we need to accomplish we can start brainstorming ideas of what our design is going to look like. We all individually came up with some ideas about how to design our hovercraft. I came up with the idea that our design should be tilted, meaning that instead of the air flow being parallel to the surface, it would be at an angle. I got this concept from my physics class, because the last group that worked on this project had trouble propelling their hovercraft forward. The solution to that problem could be as simple as tilting the air flow so that instead of the air flow only pushing in the vertical direction, it would push vertically and horizontally (acting as two force vectors instead of one). However this is just a theory, which should work but might not be compatible with our air pump and power supply. I came up with three designs, two of which are tilted and the other is flat. The top left design uses the same shape as past groups only tilted. The top right design is a flat rectangular shape that contains no horizontal propulsion. The bottom design is a rectangular shape and is tilted, which contains aspects of both top designs, however this design is not compatible with our current air flow supply. Only one of these designs would be compatible with the materials that we currently posses, but would be easy to collect more materials.

My Second Task
Once we get together as a group again, we should have more prototypes to look at and discuss about. We still need to calculate the power output of our air pump and see if it will be enough for our purposes and even if it will be enough for my tilted hovercraft design that would be able to lift and propel itself under its own power. Once these calculations are made we can make our design, test it, and determine if it is more efficient than the hovercraft built by past groups.

Summary of actual work over second weekend
How is what you did different than what you planned?

Week2 Narrative
Tell a detailed story describing what you did for your team over the weekend.

My Third task
Record what you are planning on doing for the team during the third weekend.

Summary of actual work over third weekend
After getting together as a group, we made a decision matrix that helped us decide which or our designs would be the most efficient. The datum for our matrix, for all our designs to be compared to, will be the hovercraft design that the last group created which is made from the structure of a Frisbee and is relatively cheap because they already had most of their materials. From this matrix we decided that the tilted circle design would be best.



Week3 Narrative
Since our design will be significantly lighter because it made mostly of Styrofoam, it should be able to move around more easily and with less friction. Our tilted circular design consists of a 1 inch thick 12 inch diameter disk, and is tilted at a 19.5 degree angle lifting it 4 inches off the ground in the rear of the hovercraft. The air pump, which produces the air flow for the lift and propulsion, draws air through a hole in the center of the disk and pushes it downward into a cushion made out of bubble wrap which inflates and pushes the air down causing lift and out the rear causing propulsion. The air pump will be powered by either 1 or 3 nine volt batteries, which ever one give the best output for our design. This is of course is the theory, because the bubble wrap cushion has not been applied yet because the glue that keeps the hovercraft frame together has not dried yet. However once the bubble wrap cushion is placed under the air pump, then we will test it and it should work.

My Fourth task
Unfortunately, I was unable to gain a consensus with my group when I was finishing the frame of the hovercraft design, so it might not be up to standards with some of my teammates. I took the steps of finishing the frame because I did not see a way that we could finish the design, test it, make revisions if needed, and make it presentable by the due date. Next we need to work as a group to get the bubble wrap air cushion under the air pump so that we can test it as soon as possible. Hopefully, if we divide up the work properly we can get the poster and multiple parts of the team page presentable soon.

Summary of actual work over fourth weekend
After applying the skirt and testing our design, we were disappointed that the air pump did not create enough lift for hovercraft to hover. We were also puzzled by the fact that using one 9 volt battery gave better results from the air pump that three 9 volt batteries together. We decided to modify our design to make it lighter and more sturdy since our tilted design seemed too unstable due to the tilt. Our second design consisted of the same circular disk, but with no tilted aspect therefore in order to travel under its own power it would need a external fan to provide propulsion. The problem with adding an external fan of course would be the added weight. This second design also used the same skirt design, but was created with a thinner material.

Week4 Narrative
After testing our second design with little to no success, we decided that instead of a new frame design, we should focus more on creating a new skirt design. Therefore, we back and did more research on different skirt designs and found that the height of the skirt and power of the fan will determine how much lift the hovercraft will get off the ground. Therefore, our third design with this new skirt, made of duck tape, would focus more on providing the amount of lift necessary instead of weighing less. The sides of the skirt were approximately 3 inches tall, and along the bottom of the skirt were several holes created with screws that allowed air to escape from and provide lift. After testing this design, it was determined that there was less friction but the air pump was not strong enough to lift this design. We concluded that this skirt design was our most efficient hovercraft, even though it did not hover to the extent that we wanted.

Complete Team Page
Fill out the Team Form (should have already copied the form, created the team page, linked to it and started filling it out).