whos got the most far fetched idea?

[Zippiot]

who has an idea for an internal combustion engine but doesnt have the time or such to build one?


my crazy idea is about 6 valveless pulsejets, in a sumwut linear form, arranged in a circle attatched to a drive shaft. the exhaust of each engine is slightly bent in the same way, so when the jets fire they make the driveshaft spin. at the front of the driveshaft there is a big compressor, so once these things move fast enough they perform a ram style operation. turbines cant operate safely past mach 3 beacuase the rear parts melt, but an arrangement of small valveless pulsejets that sustain ram operation should be able to hold firm above mach 3, if the engine gets there in the firstpalce.
to ensure that there is enough air the driveshaft will have a planetary gearbox...but im not sure if it will need to be a low gear ratio or a high one...depends on how much air the compressor puts in.

of course it must be spun up to operating speed before starting it, but barring a few technical problems i see no major obstacles (cept the math for figuring out how much air the compressors will feed in)

now that i read the first part i see its hard to visualize, the pulse/rams will be bolted around a driveshaft, so if you look at it from the front all u will see is a shaft in the middle and the intakes of the pulse/rams....still sounds weird

ok lets try this, the main bodies of the pulse/rams will face the same direction of the shaft...thats better but i still need to make a pic

[Zippiot]

a refinement:
after watching the history channel it apears that germany had an idea about a plane that acted like a dragonfly, vertical takeoff and horizontal flight. it was pretty much a ram jet tipped helicopter, it never was built because the war ended.

my idea is to refine my other idea, each pulse/ram attatched to the driveshaft is now jsut straight instead of having a cocked tailpipe, but now a way to throttle is will be to pitch the pulse/rams, at idle and startup they are at an extreme angle to achieve low speed flight they are brought closer to parallel with the driveshaft, and for high speed operation they are near parallel with the driveshaft. maybe keep the tailpipe slightly cocked so that at full throttle the pulse/rams can be parallel with the driveshaft but the tailpipe slightly cocked so it still creates spinning force. i am working on a few drawings of my idea and i encourange everyone to post their own crazy thought

ps i gotta leave soon so this post wont be spell checked...sry

[Zippiot]

i call it (drum roll):

THE RAMBINE!!!

ok first thing is revisions and such

the ramjets are not traditional rams anymore, it is now a giant wheel that looks like a compressor, but each square section will be modified with a type of flameholder, intake and nozzle, and fuel delivery. essentially, each segment of the compressor wheel is now a tiny ramjet!! this wheel will be attatched, by planetary gearbox, to a giant cone. this cone is covered in turbine styled blades, as you move further fron the point of the cone the more extreme the angle gets on the blades, so as it spins and compresses the air it also speeds the air up. from the gearbox the cone will spin opposite to the ram wheel, ratios and such still need to be calculated.

there are a few more thigns to it but this seems to be plausible in my head...
i am trying to get in a drawing but the way the rambine works changes everytime i try to draw it up, but i am still tryin to draw one up to help visualize it for u guys

[Mike Everman]

Yeah, way to go, though. Nice bits. There's pulse wheels and ram wheels by some company up in the pacific northwest somewhere as I recall.
I like the idea of a pulse turbine and am working on one now. Here's an old one that was good for a bit of discussion:

[Bruno Ogorelec]

Maybe not quite an engine idea, but for being farfetched, my father's railway cart powered by a pulsejet burning vaporized butter takes some beating. Circa 1970 or so.

My own most farfetched idea was a wood-burning wood-boring pulsejet. I imagined it as a copper spike with internals of a pulsejet -- like a Tharratt, for instance. Copper conducts heat really well and I thought its heat might turn wood it into flammable gas.

You'd drive the spike into a log, light it up with methanol or kerosene and wait for it to become really hot. Heat would turn wood into fuel gas, which would power the jet, and its thrust would be driving the spike ever deeper into the wood.

Of course, the thing would never produce enough flammable gas to power a pulsejet, which is a fuel-thirsty device, but the idea did amuse me. I could imagine loggers speeding down rivers on big jet-powered logs etc....

[Jonny69]

I had this crazy idea for an engine once. Luckily it was just before my final year at university and I thought what if...? So I made it as my major project (dissertation):





I present you the pulsejet turbine by Jonny69 - tadah! I want to know what happens if you use a tesla turbine on the end, the normal turbine drops the pitch right down and I reckon you can run it very short, but would a Tesla do the same?

[Mike Everman]

Again, that's ssssweet, Jonny.

[larry cottrill]

My ill-fated Synchrodyne(TM) engine. The actual build was to a MUCH larger L/D ratio than the drawing, but the length proportions are almost perfectly accurate.

Here's how it was supposed to work:

The air-fuel blast drove the tailpipe mass rearward, but at the same time was supposed to pressurize the front chamber. When the chamber area aft of the venturi reached low pressure, the front chamber was supposed to be starting to rebound compressed gas back through the narrow venturi (which was simply formed by MAJOR flattening of the tube at that point), supposedly creating low static pressure at the port (due to the high velocity there), and drawing in the next charge of fuel and air through the intake bell.

Naturally, at that time I had no idea of the importance of the intake length or that its own resonance would matter. I had never "lurked" the forums, just found them, joined up and began blasting away.

This was the very first design I posted, built and tested on the forums, away back in 2001. Of course, I've probably had a few more far-fetched ideas since then, so this isn't necessarily the "best", just the earliest. For some reason, I can't seem to find my photos of the finished engine - I'll post them if I run across them.

L Cottrill

[Mark]

In some way, I thought I would probably have the most farfetched ideas of anyone, but I see I have a lot of competition. ha I can't even win in that catagory! I try so hard, lately with my heart valve which instead of cycles per second, I'm working on beats per minute.
Or how about perpetual motion, look all around you, things are moving about, where did the energy come from, you don't get something for nothing? Or do you? The big bang or the god of your choice still doesn't explain that small detail any more than saying it has always been here or that it was created out of nothingness. Maybe I wouldn't want to know?
Mark

[Zippiot]

bruno that idea might actually work. look up a video of how they make coal for blacksmiths. once u get the wood burning it burns so rapidly that its almsot impossible to blow it out. and once its all turned to coal, well then u have coal as a fuel. these way it works is to light the fire, and circulate the exhaust (or smoke for that matter) back into the fire, as wood bunrs it releases expanding gasses, so once u get the fire running, route the expanding gasses through a tiny jet. but, it would take 1/2 a wood pile just to get things started...

larry im having a hard time visualizing ur Synchrodyne(TM), do you have any other pics?

[Zippiot]

i apologize for the bad hand writting, and the abrely visible lines, but this was the best i could do since my solid works subscription ran out...

on the right is the key
1. cement/graphite
2. flameholder
3. planetary gearbox
4. turbine blade
5. air
6. compressed air
7. direction of rotation

also towards the bottom it says angle of blades, it shows that as you move further in the rambine the angle of attack is increased to boost airspeed. the planetary gearbox also makes the cone spin the opposite direction of the ram wheel, havent decided which one needs to move faster yet...it can go either way really...
pretty much you gotta spin it up to get it started, just like a normal turbine, but this time instead of having the flame tubes stationry they are fitted like ramjets and they provide the spinning force to move the turbine. it should self sustain once up to speed, and wont (hopefully) have the problem that ordinary turnines do where the rear blade overheat and melt...

[larry cottrill]

larry im having a hard time visualizing ur Synchrodyne(TM), do you have any other pics?

It might be clearer if I could find my very last photos of it. The two little pipes in the intake bell are supposed to be fuel and starting air. Fueling relied on carburetion, with camp stove "white" gasoline as fuel. Ether was also tried. It was made from an approx. 2 ft length of 1/2-inch rigid steel conduit, with the butt of a CO2 cylinder for the nose. The venturi section is just a flattened zone in the tube, and the port is an oval hole cut and filed across. The intake bell was then added on; it's made from a short length of 0.5 inch chrome-moly tubing.

L Cottrill

[Zippiot]

wut is the heating characteristics of chro-mo? i have an aluminum co2 tank and a chro-mo tank, the chro-mo tak is not only smaller for the same amount of liquid but it has a logner life. little heavier though. u can braze chro-mo right u dun need to weld it?

if that is so then maybe i can make a more advanced design, my friend with the mig is away at college so im stuck with pipe fittings for now

[larry cottrill]

wut is the heating characteristics of chro-mo? i have an aluminum co2 tank and a chro-mo tank, the chro-mo tak is not only smaller for the same amount of liquid but it has a logner life. little heavier though. u can braze chro-mo right u dun need to weld it?

Yes, you can braze it - that's how lugged and brazed bike frames are put together. But, it welds as easily as mild steel, and much cleaner since it is of much higher purity. Aircraft A&P mechanics traditionally weld chrome moly tubing with oxyacetylene and copper coated mild steel filler rod, which alloys perfectly with the chrome-moly. The only special caution you need to take is to not allow the finished weld to chill unnaturally fast (like, blowing air on it or something), which will make the steel brittle up close to the weld. It is the most perfect steel for welding ever devised - it will really spoil you against anything else. It is considered a high strength steel, of course, and is expensive - it is what most high pressure cylinders are made of.

L Cottrill

[Zippiot]

i love to tig, mig scares me cause i got less control over it. over the sumemr i ahd to do a lot of mig work with cheap aluminum...worst welds you have ever seen!!

so chrome molly is a good metal for jets, and i assume easier to weld than thin stainless, but how well does it withhold heat? ss just seems to get red hot, and even though it stays hot for a while not much warping or anything, if the joints of chrome molly have copepr in them is there a risk of heat making it warp?

plus any more out there jet ideas? or other internal combustion?