WW1 Aviation

[ArmySGT.]

Ok, so a source for another encounter group and much fun.

Oh yeah, and a TMP easter egg buried in there, fans!

http://www.stripes.com/military-life/military-history/world-war-i-aviation-still-alive-at-aerodrome-in-new-york-1.296401

[welsh]

Awesome! A vintage flying circus and Morrow likes it! Now, if we can only have airships...
I heard somewhere these guy were thinking making a replica zeppelin. http://www.zeppelin-museum.de/home_en.0.html

Or maybe it was these guys- http://en.wikipedia.org/wiki/Zeppelin_NT

[ArmySGT.]

Consider the much lower tech level required to make WW1 aircraft and hot air balloons.

[kato13]

Semi related topic.

Given the anniversary of WWI there have been lots of documentaries on lighter than air ships.

One interviewed a pilot of a modern blimp and he happened to mention that even with modern technology Helium Airships lose 10% of their volume weekly. He also said this was only a small improvement over the WWI era ships which used cow intestine lining as a barrier.

Contrasting that I saw a supporter the US military using airships claiming that there is only a 3% loss annually when using the best materials.

Obviously a 520% loss and a 3% loss would lead to radically different annual logistical requirements. Because of this I have put any thoughts of lighter than air ships for my project on the back burner.

My google-fu has not helped me resolve this contradiction. I know the cube-square law would make it variable depending on size so I know there will not be a hard number, but I was wondering if anyone had any insight on this subject.

[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.