3 ms·

Why not fill the wings with helium or other lighter than air solid. ~Lift increases by the cube, weight by the square. I'm waiting for someone to invent an ext

Why not fill the wings with helium or other lighter than air solid. ~Lift increases by the cube, weight by the square. I'm waiting for someone to invent an extremely cheap lighter than air solid which can act like a battery.

hayksaakian 14y ago
> Lighter than air solid Is this even possible at normal temperature? I can't imagine this at 1 atm. and room temperature... after some googl-ing: http://en.wikipedia.org/wiki/Aerogel http://en.wikipedia.org/wiki/Aerogel
RobertHoudin 14y ago
The amount of lift you would get from such a small amount of helium would be practically negligible compared to the weight of the aircraft. Lighter-than-air craft require an enormous volume of helium/hydrogen - due to the cross-section of such a craft, the speed of travel is severely limited by drag. Basically, an aircraft uses wings OR lighter-than-air gas - it can't use both.
evgen 14y ago
Because now you need to make the wings airtight (no, not just air-tight but helium-tight) which adds more weight than the lighter-than-air material is offsetting.
ChuckMcM 14y ago
Well one of the challenges of both helium and hydrogen is that they are really very small molecules, and they tend to slip out through the smallest gaps. This is why the metalized aluminum skin was on the Hindenberg in the first place, and ultimately doomed it. Lighter than air solids have the issue that if you remove the air from the spaces in those solids and try to hold it out you create a pressure differential that crushes them. There was some speculation that given an ability to precisely manipulate carbon you could build dodecahedrons out of pentagons of diamond in a vacuum and then when you removed them from the vacuum they would have a net density lower than that of air, but the density ratio is so small (assuming you could build them) that you'r talking about a massive airship that ascends to maybe 3,000' on a cold day. Exploiting air density is a challenging path that has not had much success of late.

hayksaakian 14y ago

> Lighter than air solid Is this even possible at normal temperature? I can't imagine this at 1 atm. and room temperature... after some googl-ing: http://en.wikipedia.org/wiki/Aerogel http://en.wikipedia.org/wiki/Aerogel

RobertHoudin 14y ago

The amount of lift you would get from such a small amount of helium would be practically negligible compared to the weight of the aircraft. Lighter-than-air craft require an enormous volume of helium/hydrogen - due to the cross-section of such a craft, the speed of travel is severely limited by drag. Basically, an aircraft uses wings OR lighter-than-air gas - it can't use both.

evgen 14y ago

Because now you need to make the wings airtight (no, not just air-tight but helium-tight) which adds more weight than the lighter-than-air material is offsetting.

ChuckMcM 14y ago

Well one of the challenges of both helium and hydrogen is that they are really very small molecules, and they tend to slip out through the smallest gaps. This is why the metalized aluminum skin was on the Hindenberg in the first place, and ultimately doomed it. Lighter than air solids have the issue that if you remove the air from the spaces in those solids and try to hold it out you create a pressure differential that crushes them. There was some speculation that given an ability to precisely manipulate carbon you could build dodecahedrons out of pentagons of diamond in a vacuum and then when you removed them from the vacuum they would have a net density lower than that of air, but the density ratio is so small (assuming you could build them) that you'r talking about a massive airship that ascends to maybe 3,000' on a cold day. Exploiting air density is a challenging path that has not had much success of late.