Solar Cooker ProjectGoals of the Project
The Project Goal of this project is to maximize the internal temperature of a standard hot dog while also maximizing the thermal efficiency of the cooker. Efficiency means that for every watt of sun power entering the cooker, an amount of that watt hits the hot dog. For example, if 1000 watts enter the cooker, only 200 of that 1000 may enter the hot dog. This means that the cooker has an efficiency of 20%. The overarching questions are: 1. What is efficiency? 2. What specific factors impact efficiency? 3. What is your cooker's efficiency and how did you calculate your cooker's efficiency? 4. How do we best use (focus) the sun's energy? 5. How did you determine your cooker profile and how did you get this onto your cooker? 6. How did you decide where to put and how to orient the hot dog in your cooker? Solar Cooker Profile
After cutting out the supports, we evenly spaced them by using pizza slice shaped pieces of cardboard and hot glued these together to create the finished skeleton.
The finished skeleton
To lay the foil on, we had to spread Elmer's glue around the cardboard first. After we had all of the pieces cut out and decked out with aluminum foil, we went to placing them on the cooker. This was by far the most difficult part of this project, because the shapes weren't perfectly aligned, and all the shapes were a little different in size. We ended up having to cut off a little bit of the edges of some pieces, and it was difficult to fit them all together. but it ended up working out.
Cut out shapes on the cooker
How it turned out
In the end, our solar cooker turned out okay. It got pretty hot, the third hottest in the class, but it was also the third worst efficiency in the class. Overarching questions: 1. What is efficiency? Efficiency means that for every watt of sun power entering the cooker, an amount of that watt hits the hot dog. For example, if 1000 watts enter the cooker, only 200 of that 1000 may enter the hot dog. This means that the cooker has an efficiency of 20%. 2. What specific factors impact efficiency? Some specific factors that impact efficiency are: the energy the sun is giving off, the area of intake of your cooker, how well the cooker is designed to maximize the amount of sun rays being reflected into the hot dog. 3. What is your cooker's efficiency and how did you calculate your cooker's efficiency? Our cooker's efficiency was 1.78%. we calculated this by using the efficiency equation. The information you need for this is the change in temperature, the time, the area of intake of the cooker, and the amount of watts the sun is giving off. Now at first glance, this number seems extremely small, and it is. However, many other classmate's percentages were around this and the highest was 5%. 4. How do we best use (focus) the sun's energy? We can best focus the sun's energy by making a parabolic shape, to reflect the sun's energy into the hot dog. 5. How did you determine your cooker profile and how did you get this onto your cooker? We determined our cooker profile by deciding that we would use a semi sphere shape. We then drew out our profile to figure out where the sun's rays would reflect. 6. How did you decide where to put and how to orient the hot dog in your cooker? We decided to orient our hot dog straight up and down because all of the rays would meet in the middle, but it would also take advantage of human error. We decided to place our cooker near the middle because it took up half the length of the cooker and that is where our profile said most of the rays would reflect. |
How we did this project
The first step of completing this project was to sketch a profile of the shape of our cooker and how the angles would reflect. This was important in order to figure out where the sun's rays would reflect inside our cooker and where we should position the hot dog. We decided that a half circle shape would be the simplest way to make an efficient cooker. The next step of this project was to start cutting out shapes of cardboard from an 8 foot by 4 foot sheet. We decided that we would cut out six semicircular supports and from those we would place the cardboard lining and aluminum foil. Now it was time to cut out the cardboard lining pieces. This was a difficult part of the project because we had to cut out a good shape so that it would fit with the curvature of the cooker. We decided to cut out large pizza slice shapes and lay them down parallel to each other around the cooker. We also decided to place aluminum foil on the pieces right after cutting them out, and before placing them on the cooker.
Pizza slice shaped piece with aluminum foil
After getting all the shapes on the cooker, we finalized the design by just laying down aluminum foil over any gaps. This decision ended up working very well with our end product.
End product of solar cooker
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