Seems like the Egg of Columbus” to me, but I’ve been told I have an uncanny grasp of the obvious.
Given the huge volume of the pressure envelope and abundance and dependability of sunlight above the clouds, Hydrogen could be produced on board by photo-voltaic cells.
Could this BAA actually land with MORE FUEL than it had at take-off?
BMW has a Hydrogen Engine in a limited-production 760 series sedan.
And Germany is producing NT (New Technology) Zeppelins.
6 hours ago
John, your answer was so thorough that nobody else was answering. so I started new. I seen to get my best response in the first hour.
How can I give you “Best Answer” when it is the only answer?
Who would answer the Question after that?
And if you don’t think I can take criticisms, you haven’t read many answers to my questions.
They run 10-1 negative and often insulting. I seldom insult back.
One Response
Why do you keep reposting this? If you post a question, you’ll get answers; if you post an idea, you’ll get criticisms. If you can’t stand the criticisms, well grow up, don’t repost.
There were two high altitude photo-voltaic projects, both no longer exist.
One is a photo-voltaic blimp that acts as a communication and surveillance platform and it does convert water to hydrogen stored in the gas envelope in order to provide power through fuel cells during the night. This because hydrogen has a high gravimetric energy density but a low volumetric energy density, only the large volume of the blimp makes energy storage by hydrogen feasible. As it is at high altitude, the balloonets are large to allow the buoyant gas room to expand hence such an airship would have very little buoyancy at lower altitudes where the pressure needs to be increased in order to maintain structural integrity. Since at altitude, balloonets are mostly empty, only the remaining volume of the balloonets are available for the storage of hydrogen fuel. Because of this, such a vessel is not suited for production of hydrogen at altitude and delivery of said hydrogen to a lower altitude. This is simple physics, you can crunch the numbers to see where the cross over is but it’s likely not to be practical.
The other project is a very lightweight heavier than air craft that derives lift through aerodynamic means. This means a more power is needed to keep it aloft both during the day and at night and the shape reduces places volume restraints hence lithium ion batteries are used for energy storage. As more power is needed just to stay aloft and energy storage options are more limited, the aerodynamic option is also likely to not be practical to deliver fuel to lower altitudes.
What you are proposing is a hybrid where the craft is still heavier than air but offset somewhat by buoyancy. Yes there is aerodynamic lift and the shape allows more volume than the heavier than air option but less then the lighter than air option and the shape imposes much greater drag though at altitude that drops off with the air pressure. The ability of such a craft’s ability to physically deliver hydrogen fuel to lower altitudes will be somewhere’s between the airship and the aircraft options. Note that the average of “not likely to be practical” and “not likely to be practical” is “not likely to be practical”.
Note that the high altitude blimp program has been canceled and the NASA Helios heavier than air high altutude photovoltaic aircraft was lost in flight.