well originally you asked:
so It was natural to think that that was what you were what you were looking for. As my previous post suggests, that is probably not possible. If you want to reduce the volume significantly, I think the way to go is to reduce the weight of the balloon, not the gas...
The lifting capacity of He and H2 are very similar, and not close to a factor of 4. The following example explaines why.
Lets say we have a balloon with exactly one mole of gas inside which will have volume of around 24l. If we fill the balloon with H2, the mass of the gas inside the it will be...
Oops instead of: For a symmetric profile the moment around the center of gravity will be zero, It should be: For a symmetric profile the moment around the aerodynamic center will be zero
I am going to hold a lecture on aerodynamics for a group of high school students, after which a competition on constructing the best glider is held. I think the planes will be made of sheets of balsa wood, and they are therefore likely to have flat wings. To help them succeed, I plan on telling...