A Challenge - To Any Structural/Electrical/Areo Engineers, Physicists, Scientists

[Drame22]

Hello everyone,



I am brand-new to this forum, and I signed up with a singular purpose. I wished to present a challenge that has been dogging me for years, to a community of professional and (more importantly) knowledgeable people, who could tell me A) whether this was at all practical outside of theory, and B) how expensive it would have to be, how heavy, etc. As I am no engineer, or scientist, I have no choice but to present it in a forum. If I had the know-how, I'd simply do it myself. I do have a basic understanding of physics, electrical work, mechanical and engineering work, but I am not formally educated in these matters; my knowledge comes exclusively from talking to experts.


So, let's get to it, shall we?



I have always been enamored by airships. The seeming impossibility of something so large, floating almost delicately in the sky, has always held my attention. It was a terrible shame when the entire industry was shut down by a single accident(Hindenburg). Which is why I was so excited to read articles a few years ago about a possible resurgence of airship usage, primarily for military purposes but there were mentions of civilian models. Which brings me to my post's point. I would like your help, community, to flush out an airship design(or rather, concept) that I've had rolling around my head for ages.



I'd like to run through my various ideas, and let me re-iterate that I am not an engineer. That's why I'm here; to get some professional advice, and hopefully technical help, on this theory.



I'm envisioning an airship, of a similar size to the Hindenburg, but lifted by vacuum, not by gas. It seems to me the inherent problem with gas(aside from the exploding and the dying) is the volume you need; you need bags to lift the ship, pressurized tanks to lower the ship, pumping systems, monitors, etc. I was wondering about the practicality of, say, 15 tanks of vacuum, arranged in a 3x5 down the length of the airship. This would give the captain ample control of the ship. You could, for example, "land" on a mountainside by simply pumping atmosphere into the left-hand tanks, forcing more of the ship's weight to shift left, to 'pin' it to the mountain.


I also read an article about solar panel hexes, that some countries are considering using for highways. They are very thick and sturdy, and plug into one another, creating essentially a free power grid. I had given some thought to both powering the airship and allowing for possible flight, by setting down a 'runway' of these panels along the top of the airship. That would create drag and increase weight, but would also allow helicopters, perhaps even planes, to land on the airship, like a giant flying carrier.



The reason behind all this, if you'll allow me a moment, is my desire to help humanity. A lot of people say that, when what they mean is "I want to help myself, and those I care about, succeed and thrive". I'm a shade different; I honestly want to see the world improve, for everyone, not just my city, county, or even country. And I think that modern airships have a distinct role to play. With even a diesel-powered airship, you're saving(estimated) 20% fuel costs over traditional sea shipping, just by dint of not having to force your structure through water; significant even if you aren't an international company worth billions.


What makes airships so much better than smaller craft, in my opinion, is their capacity. Even now-obsolete designs like the Hidenburg could carry multiple tons of cargo, and presuming the land was open enough, could land literally anywhere. A modern design could combine the handling of a helicopter with the capacity of a small ship. Let me put it in an example; there are many places in Siberia that are only accessible via muddy, unpaved roads. Whole towns and military bases(those are likely intentional) are completely cut-off from air/rail/sea supply routes. That's not even discussing South America, southern Asia, north Africa, etc. A fleet of such ships could easily make life better for countless millions, and in my mind, the best part is the business incentive behind it. Companies so rarely see eye-to-eye with consumers, but no one(aside from shipping companies) would disagree with a ship that can deliver it faster, cheaper, and can travel longer without needing maintenance or fuel.



I apologize for the above digression; here are my questions as concisely as possible:


-Is this idea, in theory, feasible?

-What would you change about my concept, to make it cheaper/stronger/better?

-How strong, and with what materials, would these vacuum tanks need to be designed?

-How strong, and heavy, would pumps have to be, to handle pumping out close to 100% of atmosphere from a tank?

-How large could an airship be, before it's bulk starts outweighing(no pun intended) it's use? As in, how long can an airship get before small gusts of wind shift it multiple yards before the ship's engines can compensate? That would be deadly when unloading heavy equipment.

-How much lift can you generate with vacuum? How many tons could a theoretical airship carry, past it's own weight?

-How fast could you get an airship to go(without damage), and what is the ideal shape for an airship, in terms of drag?

-Could the superstructure of such a ship be made strong enough to land on ground(as opposed to hovering just a few feet above)? My thought here was of the old airship videos, where a gust of wind would shift the entire ship before the ground crews could control it. If you vented the 'vacuum', it's own weight would keep it on the ground and steady for loading/unloading.

-In the interest of safety, what do you think would be a competent escape system? My only idea so far has been to copy-cat the Russian shuttle caps, which parachute to safety, float, and have food/water onboard in case, as well as a homing beacon. Those could line the sides of the ship, and use shaped charges to jettison it to a safe distance before the chutes deployed.






This is not a pie-in-the-sky post; I'm asking serious questions and hoping for serious answers. Ideally, I would like to walk away from this forum with a coherent plan, and maybe even a schematic, of an airship to present to investors. Who knows, if the community here is as helpful as they appear to be all over this forum, than I may just name you all co-owners of the first modern airship.




I look forward to your replies. Please, do not be soft. If I'm saying something that makes no sense, it's because I do not have education in this field. Correct me! I'm here to learn, and to flesh out this idea. I am seriously considering starting a "kick start" campaign to raise initial funds, which would fund a single 'test' airship, about half the size of my idea, but I wanted to first speak to a community of professionals and hobbyists to see if my idea would even make it off the ground (pun definitely intended). My primary concern is the concept of vacuum tanks, and on-board storage of electricity. If those concepts are addressed and fixed, the rest is fairly basic engineering, which at least I can comprehend, if not fully understand.




Regards,

[Kelly_Bramble]

A lot of words....

What you're proposing is a Vacuum Airship – this is not a unique idea... First proposed by Italian monk Francesco Lana de Terzi in 1670.

At a vacuum there would be about 14.7 psi at sea level exerting pressure on the external surfaces of the tanks. As the altitude increases the atmospheric pressure would become less.

Hot air Balloons utilize heated air with is less dense to create the buoyancy to fly. The pressure differential between the hot air and the atmosphere is what makes the hot air balloon expand and ultimately float up.

All you need to make his work is an engineering material that is strong and light enough to withstand 14.7 psi to create the buoyancy to fly.

I don’t believe any such practical engineering materials are in existence… Moreover, you would need vacuum pumps, regulator valves, and a whole lot more technology as well as an an energy source to operate all of this stuff.

Thinking and being creative is fun and you should continue this, however knowledge of engineering, physics and history of inventions that failed would help you to not have “pie-in-the-sky post”.

[jboggs]

You could test your own ideas by simply building a framework with a very thin skin and attach it to a vacuum pump. When you can build it light enough so that the entire structure weighs less than the air it displaces, it will rise and float.

You know this already but it might help your visualization of the situation to state your premise a little differently. You're not really "filling" anything with "vacuum". You are removing air from a fixed volume and not replacing it with anything. The floating effect comes from the very slightly different pressure of air at different heights. Effectively the air in contact with the lower surfaces of the airship is at a slightly higher pressure than the air in contact with the upper surfaces. That difference in pressure applied over the large area results in enough force to overcome the weight of the airship, thus causing it to rise.

Since we live in it, we don't really feel it, but 14.7 pounds of force per square inch of area is a lot of force. The skin of your frame is going to have to be very strong to withstand the force generated by a complete vacuum.