Thermodynamics B/C

[Crtomir]

Hello I came here because I have a few questions
1). i see aerogels are a abig thing for thermo, but im confused because i see alot of pictures of them seeing them in a pebble like form but i also see picture of it being one sheet. How exactly do aerogels work?

2).in the rules it says the beaker has to be roughly ratio'ed at 1.4 times the diameter, ive been looking all around abd the closest ive seen is 1.2 , does anyone know where i can buy one with that ratio?

Takuramen if you REALLY wish to buy aerogels you can find blanket type ones like Pyrogel here
http://www.buyaerogel.com/product/pyrogel-xt-e-blanket/
make sure they're hydrophobic (waterproof) or else it will catastrophically degrade. But a small been said by others, the test and prediction is more important to your score.
Edit: I have been informed by Alex RHC that many contain fiberglass so read the MDS closely

Yes, this aero-gel "blanket" does contain fiberglass, which is forbidden by the event rules. We did not purchase this product for this very reason.

[Crtomir]

With all this talk about aero-gels, most of the ones that are cheap enough are aero-gel beads, not monolithic blocks of aero-gel. A 20x20 cm monolithic block of aero-gel is prohibitively expensive. Filling up a box with aero-gel beads leaves a lot of interstitial space between the beads that is filled with just air. I am wondering if, in the end, aero-gel beads actually work better than just a solid styrofoam block or if, because of the air gaps, the composite system becomes less insulative than just a simple solid styrofoam block? Has anyone taken any real data on this to PROVE that aero-gel beads packed in a box perform better than a solid block of styrofoam?

[arv101]

Where can you find more practice problems to do? Also, where is the best place to learn how to do the actual problem problems, which involve math.

[JoeyC]

I tend to just find college level textbooks (like Schuam's outlines) and learn off of those.

[lamppost]

Anyone know a good place to get polyurethane foam? Can't really find any good places

[LittyWap]

Anyone know a good place to get polyurethane foam? Can't really find any good places

SmoothOn makes a lot of pourable urethane foams. All you have to do is mix parts A and B and pour the solution into a mold of some kind. I made a mold around my beaker and made a very good insulating device in an hour's time.

[Tesel]

I see people talking about using aluminum foil or similar materials to trap heat radiation. Is that your outer layer, as in a lining for whatever you use as a box? Also, what solutions have you found to make a rigid layer around your beaker?

[retired1]

Personal opinion-- Silvered mylar would work a lot more efficiently. Think of coffee bags for stiffer material and some chip bags for thinner material.

For the foam question- Why not us a can of spray insulating foam from any big box store. A lot simpler to use and very probably cheaper..
If you want it to touch the beaker, spray the beaker with cooking spray or WD-40. The cooking spray is a lot easier to clean up.

[Alex-RCHS]

Anyone know a good place to get polyurethane foam? Can't really find any good places

SmoothOn makes a lot of pourable urethane foams. All you have to do is mix parts A and B and pour the solution into a mold of some kind. I made a mold around my beaker and made a very good insulating device in an hour's time.

That sounds like urethane rubber rather than polyurethane foam. Can you provide a link?

[retired1]

It is polyurethane. Just one example is Great Stuff from home depot.