4 ms·
Squared-cubed law for tank weight and fuel weight. So hydrogen will have poor energy density at small scales. Not sure where it dips below that of batteries but
by sacrosancty 4y ago
Squared-cubed law for tank weight and fuel weight. So hydrogen will have poor energy density at small scales. Not sure where it dips below that of batteries but rockets are OK with it, so smaller than that.
Perhaps if you store it in a balloon? But then volume would bed a problem for an aeroplane.
- mattmaroon 4y agoThe square cubed law argues in favor of something that is more energy dense by weight but less by volume right? You make the wings a little bigger and the surface area increases a lot less than the volume. There’s also the potential of enlarging the fuselage and storing some there too.
- sacrosancty 4y agoIt's about the pressure vessel's weight. That goes up with the square of the linear dimension while the quantity of fuel goes with that cubed. I don't think finding space to fit it is the problem. In the case of normal fuel, there's no pressure vessel so it can be much lighter.
- pfdietz 4y agoIn a tank dominated by pressure loads, wall thickness increases in proportion to the linear dimensions of the tank, so no, tank mass is proportional to volume.
- sacrosancty 4y ago
- coderenegade 4y agoYou would use cryogenic storage for aviation, not a pressure vessel. By most metrics, LH2 delivers better performance than other fuels, but other fuels are easier to deal with and generally "good enough".
- pfdietz 4y agoRockets are in fact often not ok with that. Using hydrogen in the first stage of a launcher is a bad idea.