Tin Can Turbine 1st flame test..

Well the title kinda speaks for itself. I wish the results were more impressive, but at least the video has fire in it.  Enjoy : )

Ok….the bad:

Too much fuel…..thats obvious

Too much mechanical friction. The re-worked compressor lost a blade which fouled the mechanism. A new re-re-worked compressor will be constructed. Also, attempts to reduce friction and weight of the turbine shaft and fans will be re-thunked. Yes, I’m inventing new words….I’m aware.

And Conversely….the good:

All of the materials used are actually withstanding these temperatures well.

We have a better starting proceedure

The fuel system (so far) seems quite adequate.

More to come when refinements are accomplished…..

Turbine progress continues…

So after some refinement, as well as component searching, the development of the jet turbine is still moving forward. Below are some images from the start till the current date.

 

The above are images of the original conceptualization of the Compressor and turbine fans, all mounted on the central shaft that runs through the entire engine. As I mentioned earlier, after further research it was discovered that a radial compressor fan, as opposed to an axial, (as we were first intending to use and as is seen above), would be a better choice if we had any hope of success. So we designed our first radial compressor fan from plywood, above right. This seems strange in a flame breathing jet engine, but when the engine is running or at least being spooled up to some rpm by an air compressor prior to running, all the flame will be directed out the backside and away from this compressor fan, so plywood has been used succesfully in the past on some small units. We unfortunately, misjudged the rapidity of our fuel delivery system, which lit in the combustion chamber much quicker, and more profusely than we expected, and again as mentioned earlier, by the time we got around to jetting in the compressed air for starting, the compressor was…….well, toast. Ahhhhh, live and learn. Add this to the list of things we figure out to do only once in life…..like licking 9-volt batteries……don’t ask. But I don’t recommend it. : )

On a side note, in the images above you can also see the internal shaft connector, just behind the fan blades to the right, that melted, and which we seem to have found a suitable replacement for. Turns out, it was made of aluminum. This is a no-no, as it will in no way withstand the temperatures inside this unit. At this point we are hoping the metals that we are intending to use here will withstand these temperatures. I’m not sure yet, and if they do, what their duration will be. But aluminum….no way.

You also may be asking yourself why a radial instead of an axial compressor. Our goal is simplicity, and quite simply a radial compressor is more simple and efficient than an axial. To get an axial that will produce the same pressure increase that we would get from a radial, we would need three fan blades in sequence and a specially shaped duct to accomplish the same thing we get from the single radial fan slamming the air outward against the sidewalls of the can housing. It still may not be enough to allow this unit to work, but it’s by far the best choice.

Anyway….some more shots.

 

These above shots are of the construction of the new all metal compressor fan unit. This one shouldn’t burn no matter how stupid I am in the starting process! All very simple to fabricate by the way out of the same tin can stock.

 

And finally above is the unit on the impromptu test stand we are using for run tests. The shot to the right shows the tail with the turbine fan clearly visible. The shot on the left is the intake where the new metal compressor will be inserted. The “horns” on the outside are the fuel inlet ports, the inserts in these regulate the fuel flow and have been adjusted to reduce this flow so that the next run won’t be quite so flooded. If, and thats a big if, we can even get this unit to self sustain and run, I will then work on attaching a compressing exhaust tube to the tail of the unit in an attempt to gain some thrust and efficiency. First things first though……if this thing will even self sustain and not burn up or mechanically fail in the process…..I will be amazed and impressed.

Simple Gas Turbine Project

Yes….I know the word Simple, and Jet Turbine are truly oxymorons and generally do not belong anywhere near each other in the same sentence, but my goal with this experiment is to see if it is at all possible to make a working jet turbine out of common everyday materials and without any over complexity…..in essence….so the average person can make one. I figured climbing Everest in surfing attire with a Sumo wrestler on my back was too small a challenge….so I settled for this instead. Here are some images of its inception:

 

Here are some images of the preliminary fitting of the turbine fan, and the basic design which is crafted from readily available materials….. so far simple cans from the grocery store, and nuts and bolts to create the central turbine shaft.

After this fitting, more research was done and a radial compressor was constructed, as well as a more refined turbine fan. The design is intended to use an alcohol based fuel, and its internals (right now a secret) were constructed in such a way as to attempt to maximize this usage. The unit once completely assembled was dry tested with an aircompressor and spooled up well prior to its first flame test, so fast in fact that it almost sounded like a pneumatic dentist drill.

The first flame test, was conducted last evening, and two flaws were discovered:

1st:  The compressor fan which normaly doesn’t see much heat and was therefore constructed of lite plywood, needs to be made of metal. The starting proceedure was as follows. Fuel was connected, inside burner was lit, small air supply was then turned on after flames exited both ends of the jet…(we didn’t expect this and were suprised at how fast and effective the fuel delivery was, this may have to be reduced….but that was a success at least!)…after turning on the air and beginning to direct it onto the compressor fan inside the jet for starting we noticed the ply compressor blade was already catching on fire. If we had already had the compressor spinning and then “lit” the engine, perhaps we would have avoided this and been able to go further, but, seeing as how things seldom go as planned with experimental designs, recreating the compressor fan in mostly metal seems a good idea for the future.

2nd After dissassembling the engine after it’s first run attempt, we noticed the connector thimble…a threaded tube that accepts both ends of the drive shaft through the middle of the motor, had simply melted into a glob. Since turbines tend to not like melted globs of metal  inside of themselves that once used to connect components spinning at ridiculous rpm’s, we will have to find a suitable, yet simple solution for this before we proceed.

More to come once solutions are found!!!