On the way to school today I spotted some large-scale (big enough to hold people in the gondola) hot air balloons floating above our fair city. This really got me excited to get to work on our project in class! Balloon Fiesta is on its way; look to the skies in the morning to see hot air balloons in action.
Today we worked on prototypes in class. We worked out a pattern for our design using the triangle model as can be seen as a link on Isabel's blog ( http://vimeo.com/8557013 - this is a link to the video). The shape will have an equilateral triangle as the base (which will end up being the top of the balloon). Using some volume formulas from our bookmarks we have determined that the base triangle will have to be about two feet minimum on each side for there to be enough volume inside the balloon to create lift.
Please look at the pictures that Isabel has posted for today's lab-work: http://unknown-scienceclass.blogspot.com/2011/09/prototype-mockups.html
In the first two pictures you can see our tiny-scale pattern for our initial concept of the design. This model is constructed of equilateral triangles that are of the same size. The base triangle is two inches on each side. The four triangles together create a larger equilateral triangle with four inches for each side. The next picture is of our first functional prototype test subject in its not-yet-constructed form. This design is slightly altered from the tiny-scale design in that we changed the angle of the side triangles (to 70 degrees instead of 60 degrees) and cut off the tips (so that there would be an area to put the fuel source). We did this to increase the volume of air contained within the vessel and to increase the distance between the top of the balloon and the fuel source. The next two pictures are of the construction process. The final picture is from after our first attempt at checking for balloon buoyancy. We used four candles, and preformed our experiment in the "Center of the Universe." The inside of the vessel did get hotter than that of the atmospheric temperature. Based on our collection of formulas (contained in our bookmarks) we believe that the reason that our balloon did not float well is because there was not enough lift for the weight of the construction materials.
As can be seen, this prototype caught fire. We did not use alum-paper for this prototype, but this experiment shows how the alum-paper would be of benefit for our next production model. Also finding a way to centralize the heat source would help prevent the sides of our balloon from catching fire. We still have yet to address how to attach the fuel source to our balloon. We have put some thought into a design for this, and once we construct the proper size balloon we should be able to work on getting our fuel attached to the rest of the construction.
We'll get some images of alum's awesome fire-retardant powers up soon!
Wednesday, September 28, 2011
Monday, September 26, 2011
Some pictures
The first picture is of the mess I made while trying to help make our first attempt at a fuel source. The second picture is one of the methods we tried for creating alum paper. The picture with me and the hair dryer is of a different method we tried for making alum paper.
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Balloon Project #1
This is my first blog for our hot air balloon project. We've done some at home experimenting. We constructed some geodesic domes out of different materials (printing paper, parchment, and tissue paper) and used clear tape to hold them together. Through this process we have determined that we need to make the paper portion fire-retardant, and figure out some other way to attach the pieces of paper together. The paper becomes too hot and will catch fire without a "fire proofing" method. The heat causes the tape to melt and loose its cohesion even before the paper starts to scorch. Also the melting tape seems to concentrate the heat onto the paper, contributing to the paper catching on fire.
Today in class we did some experimenting with Alum (used in picking, clothes dying, and paper marbling). We found that soaking paper in an alum-water solution does in fact make the paper much more fire resistant. We made some sheets of fire-retardant alum paper out of tissue paper and some newsprint.
We did some experimenting with wax and cotton for the fuel source. From the various examples of functioning balloons I have seen, this could be an effective method for heating the air inside our balloon. This method does create quite a bit of heat. Also, it stinks and produces some soot and smoke. The other method I have seen for heating small scale balloons is birthday candles. This might be a good method because the formula we found on the Internet for lift used birthday candle count for the heat source (number of candles per amount of cubic space for amount of lift in weight).
Our group is leaning away from using the geodesic dome design. The math is much more complicated than I had anticipated for figuring out lift. There is a much larger amount of surface area to contend with (in terms of connecting the many pieces together) for the dome than some of the other shapes I have seen used. We can try some different shapes once we have a dry supply of alum-paper. The tetragon shape might be the simplest to construct, but we should look for some kind of pattern to determine the length of the sides of the triangles. The other idea would be to make a cylinder, yet attaching a top to this shape might prove challenging.
We still need to address attaching the fuel source to the balloon. This would be in part dependant on the fuel source we decide to go with (wax-cotton wrapped in foil or birthday candle). I'm waiting on pictures to post for the experimenting we've done, please look forward to them in a future post.
Today in class we did some experimenting with Alum (used in picking, clothes dying, and paper marbling). We found that soaking paper in an alum-water solution does in fact make the paper much more fire resistant. We made some sheets of fire-retardant alum paper out of tissue paper and some newsprint.
We did some experimenting with wax and cotton for the fuel source. From the various examples of functioning balloons I have seen, this could be an effective method for heating the air inside our balloon. This method does create quite a bit of heat. Also, it stinks and produces some soot and smoke. The other method I have seen for heating small scale balloons is birthday candles. This might be a good method because the formula we found on the Internet for lift used birthday candle count for the heat source (number of candles per amount of cubic space for amount of lift in weight).
Our group is leaning away from using the geodesic dome design. The math is much more complicated than I had anticipated for figuring out lift. There is a much larger amount of surface area to contend with (in terms of connecting the many pieces together) for the dome than some of the other shapes I have seen used. We can try some different shapes once we have a dry supply of alum-paper. The tetragon shape might be the simplest to construct, but we should look for some kind of pattern to determine the length of the sides of the triangles. The other idea would be to make a cylinder, yet attaching a top to this shape might prove challenging.
We still need to address attaching the fuel source to the balloon. This would be in part dependant on the fuel source we decide to go with (wax-cotton wrapped in foil or birthday candle). I'm waiting on pictures to post for the experimenting we've done, please look forward to them in a future post.
Tuesday, September 13, 2011
Major in Education???
http://blogs.edweek.org/edweek/rick_hess_straight_up/2011/09/want_a_38_gpa_major_in_education.html
The article about majoring in education doesn't completely surprise me, but i do find it a sad situation to contemplate. There are some aspects of American education that are due for reform. I don't have all the answers, and there are aspects of what is going on with this trend and the "dumbing down" of Americans. Maybe we need to let go of making people feel like they are production models from a factory as Sir Robinson suggested, and maybe we need to re-evaluate our standards as is suggested in the article.
The article about majoring in education doesn't completely surprise me, but i do find it a sad situation to contemplate. There are some aspects of American education that are due for reform. I don't have all the answers, and there are aspects of what is going on with this trend and the "dumbing down" of Americans. Maybe we need to let go of making people feel like they are production models from a factory as Sir Robinson suggested, and maybe we need to re-evaluate our standards as is suggested in the article.
Monday, September 12, 2011
Getting the engine started....
Today in class our lab group started to construct our candle powered boat. We did some experimenting with coil heating, and have determined that our coil-shape might need some adjustments. We also spent some time discussing vessel shape and design. We'll bring our improvements to class next Wednesday.
We also got our blogs somewhat linked, as well as bookmark lists. This should help us have a stronger connection as a group.
I didn't get any pictures from class today.
We also got our blogs somewhat linked, as well as bookmark lists. This should help us have a stronger connection as a group.
I didn't get any pictures from class today.
Wednesday, September 7, 2011
candle observations
1. not currently on fire
2. 1-ish mohs rating
3. displaces 80mL of water when submerged
4. weighs 34.2 grams
5. floats
6. wet after submersion
7. not glow in the dark (without being lit)
8. when spun it, it spits water (from submersion)
9. spins on its corner
10. according to Monty Python "It's a Witch!"
11. it rolls on its side (without drugs or wheels)
12. the wick has a wire in it
13. it will roll while burning
14. it will burn while rolling
15. spinning puts out the flame
16. gets warm when burning
17. density = 0.4275g/mL3
18. wick broke and stuck to the side during spinning
19. not alive
20. unable to move independently
2. 1-ish mohs rating
3. displaces 80mL of water when submerged
4. weighs 34.2 grams
5. floats
6. wet after submersion
7. not glow in the dark (without being lit)
8. when spun it, it spits water (from submersion)
9. spins on its corner
10. according to Monty Python "It's a Witch!"
11. it rolls on its side (without drugs or wheels)
12. the wick has a wire in it
13. it will roll while burning
14. it will burn while rolling
15. spinning puts out the flame
16. gets warm when burning
17. density = 0.4275g/mL3
18. wick broke and stuck to the side during spinning
19. not alive
20. unable to move independently
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