Friday, October 05, 2007

A Steam-Powered Model Airship Project

Recently I started a new project. Many of my old projects may have gone by the wayside, but this one should stick. You see, I intend to build a steam-powered model airship, and have it be functional. I will be building this airship with parts I have around the home, putting them together, and then finally have it move under it's own steam power when I'm finished.

The Engine
I started by working out a design for the engine. The steam engine is perhaps the most important part of this project, as it will be the central power core. I based the design off of a model steam engine I saw for sale on eBay, and changed it from a piston engine to a turbine. Why a turbine? Because it's actually easier to build than a traditional piston engine, particularly at that size. ^_^

I originally intended to have the engine built together in the gondola, and then run a drive belt between the turbine drive axle an a new axle that would run the full length of the airship's envelope. That would of course require multiple gas bladders in the envelope, and make inflating very complicated.

The nice thing about the turbine is that it doesn't matter where the axle is located, as long as steam can get to it. So, I can move the turbine portion of the engine to the back of the air ship's envelope, as long as I have a tube running from the main boiler to the turbine.

Now the question comes to what power source to use. I had originally wanted to use a candle, but I am unsure if the head would be enough to build steam. There are a couple of other options, one of which is using an alcohol based fire. This is something that I will be working on this next week.

The Lift
Once the weight of the engine (and water, and fuel) has been figured out, I can calculate how much helium would be necessary. Helium has a lift factor of 1.113 grams per liter, meaning that it's weight is that much more lighter than air. So, from that I should be able to calculate how many liters of helium would be required to lift the engine and enclosing envelope. Then it is just a matter of building the envelope, and the gas bladder.

The Envelope
I intend to build a semi-rigid envelope, built out of paper-maché. The frame will be made with twine dipped in either starch or paper-maché glue. Either way, it will be roughly the shape of a Zepplin, though I reserve the right to make changes if necessary. ^_^

The rigid design will allow the turbine in the back to function with little addition to the weight of the air ship.

Future Plans
Once the initial design has worked, I plan to add a generator to the turbine (in a new design), and add electric servos and a radio control. That way, it will still be steam powered, but I can do more with it than move in one direction. I will also enclose the turbine, and recycle the steam into water, reheating it and making the engine more efficient.

Perhaps, once I can get the design worked out, I will hold a race with anyone else who is so inclined to build their own steam-powered airship. ^_^


Robert said...

I've been trying to figure out what sort of engine design to use for a similar project, would you perhaps share where you found the basis for your design?

Danish Mishra said...

I am planning to make an airship for my minor project which is a part of my undergrad curiculum. Perhaps you can help me by sharing the blueprints of your design.
Will appreciate your help