WW1 Aviation

[mmartin798]

As I too have been looking at lighter than air ships, I can share some of the things and misinformation I have found. It's not an easy topic.

First there is the choice of lifting gas. There are three main choices with different safety, efficiency and economic factors. The safest is Helium. Helium is non-flammable and is only 8% less efficient than Hydrogen. It is also the most expensive many orders of magnitude because of it's scarcity. Hydrogen is the most efficient lifting gas, it is cheap and easily made in flight, but it is very flammable. The third gas is the least efficient, but it is also non-flammable and cheap to produce in flight. That gas is steam. Hot air zeppelins were used and the gas created as a byproduct of the engines running. As late as 1973 there were airships being made using steam.

The gas loss is one that I can get the numbers to calculate, but this is also where I found some surprising misinformation. Both Helium and Hydrogen have significant gas loss, but the gas loss from Helium is greater than Hydrogen. I did find an article online that said the opposite, so watch your sources. The gas loss from steam is very low through the material, but since lift is more from the heat, that is really not a concern

Right now, I am considering an airship with a hybrid lifting gas system. It would be a rigid design with interleaved gas bag that would contain either H2 or steam. The thought being the H2 bags would give it neutral buoyancy when the engines are not running, but when the engines starts, you could quickly get some steam going and fire up the H2 generators to gain altitude quickly while minimizing the risks involved with strictly H2 as the lifting gas. It's performance would not be the best, but it is a compromise afterall.