Tip Jet helicopters

[Luc]

Hi again guys,

Originally posted by poze4
my friend goody and i have decided on a tip-jet helicopter rather than the prop-copter, the design seems simpler(except jets) and more legitimate
this is the site we have purchased the plans off
http://alternative-technologies.org/aircraft.html

Good choice guys.

Now, don't be concern about the "Jet Engine" If it's a pressure jet ... You have the right guys here and it is not that hard to do.

I am more concern about your plans and especially the engine in it. You need to know, that most of the plans present on the Net, are copys of someone else, which are copys of copys of copys. The Net is the perfect place for stealing copys of copys. Strangely, the plans you have ... I have them here. The chopper is not that bad but the engine .... Hummmmm .... Good luck.

Ask your self one question ... Galvanized steel pipes ... For an internal combustion jet engine which bound to burn that fuel in the areas above 1000°F ... Better think twice about it if you plan to fly for more then 30 seconds.

Better think more in terms of ... Stainlees steel 321 or at least ... 316L.

Just ask the right questions at the right place and you guys will be flying soon.

Cya,

Luc

[Luc]

Okey,

That enough for my first day here. I am done destroying posting ... He he he. Sorry about that guys, but I could'nt help it.

May I make a sound recommendation????

Before we go any further on pulse jets, pressure jets or RAM jets, may I recommend that we all go back to the basic and start over, because I have no intention of destroying everything that will be posted next.

There are 2 very good information sources with nice peoples that will take pleasure assisting you in your projects, venture and questions.

The first one is www.glc-inc.ca and its forum members and the second one is www.pulse-jets.com

Best regards,

Luc

[lightweight]

I have heard of many people using ram jets or the ram-type jets used in the German WWII V-1 buzz bomb google it and you will find many sites offering plans


In the eternal search for the ultimate ultralight
-Lightweight

[Luc]

Hi lightweight,

First, the German V1 Bomb did not use a RAM jet, but an Argus Pulse jet.

Using RAM jet is not something you will often see unless you can find a user that can accelerate this engine above the 400 Mph mark. Before that speed, I don't beleive you will see a RAM jet operate or operate properly at least, because this is exactly the inherent pathology of this engine. It can operate on its own below this speed.

Now, you have to be very carefull with the "Many sites offering plans". Like I said before, alot of these sites have taken or copied these plans from other sites and most often, they have been modified or tampered with.

Months ago, we had a "Plan regeneration program" where we used to take most of the popular plans, verify and validate their integrety and offered them for free to users interested in building. We had to quit that for lack of time doing our own stuff.

Just for the pressure jets plans, you can't imaging the numbers of iterations, modifications and misleading dimensions we found just for on engine.

Just be carefull with those.

Cya,

Luc

[Bob Kelly]

Luc
Very interesting ! do you have plans on the net for your engine or do you sell the plans or something ? or a web site to visit ? i'ed be interested in it !
....
INteresting about the pattent ! i bet it took a lot of experimenting to figure it all out ... Good work !

I've been experimenting with ram jets mostly here at my place just trying to get one to work with no success ... I guess the tollarances are more critical than i figured !!!!!

C ya !
Bob............

[Luc]

Hi Bob,

Originally posted by Bob Kelly
Luc
Very interesting ! do you have plans on the net for your engine or do you sell the plans or something ? or a web site to visit ? i'ed be interested in it !
....
INteresting about the pattent ! i bet it took a lot of experimenting to figure it all out ... Good work !

I've been experimenting with ram jets mostly here at my place just trying to get one to work with no success ... I guess the tollarances are more critical than i figured !!!!!

C ya !
Bob............

Welll ... As for selling plans, you need to understand that first, we are a commercial company that manufacture the engines for industrial applications and it would not be good pratice to scaters plans across the net, especially knowing that there are few peoples that would love to put their hands on those even if they are "Patent Pending". We mostly sell complete engines or parts as peoples need them.

But we do help individuals build their engines as long as it is for own personal use. The first thing you have to do is to select an engine model thrust wise. Then, we can send you a set of "Copyrights released" plans of the first generation selected engine. Afterwhat, we guide you in what you must not do and what you can do. You need to remember that the first generation pressure jets plans available on the Net, will not allow you to build a fully operational engine, but we can provide you with parts or tricks that will make this engine work properly.

As for you comments on our patents and the good work, it actually took 5 years working with these engines, over 1/4 million $$$ in investments and more then 15,000 liters of propane to get there and crack the secret code . Eugene was a very clever guy you know.

As for the RAM, it is not all about tolerance you know, but more about the operating conditions. Unless you can provide this engine with sufficient inlet air velocity, this engine will not run ... End of the road. You can bend the rules but you can't break them.

Now, a RAM jet will only start operating in the areas of 400 Mph. (586 Ft/sec.) and that's the lower limit. Unless you have a damn good air blower or leaf blower to acheive that figure, don't even think about it. After that, your RAM jet needs to incorporate a sort of flame holder or a set of air flow restriction tubes inside the chamber to create turbulence and slow down that air to speeds below the flame propagation speed, which is below the 98 Ft/sec. mark, depending on the fuel type used. After that, it is only a question of shape and areas.

And of coarse, there are always those Web genius that will claim having the perfect set of plans for home built RAM jets, for $30.00. They really make me laft you know .

Before you buy any Website RAM jet's magical set of plans, always ask your self this question Bob ... "Why would I be able to make a RAM jet with $30.00 plans set, when NASA invested Millions just to discover that a RAM Jet is a pathology below 400 Mph.

All this said, you can still build one. But stick to the rules, don't try to break them ... And most of all, peoples need to stop seeing the magical solution everytime they see a Website saying ... "BUILD YOUR OWN RAM JET".

If you go to the NASA Website and search for the Hyper-X project or X-43, there is very good documentations about RAM Jets, SCRAM Jets and PDE engines. Read them and only then, you will be bound to more successfull trials with your Baby.

Regards,

Luc

[lightweight]

LUC

If you look, you will find that some are ram TYPE Also, there is a few special subsonic ramjets that only need to go 100 mph, the better ones less

[Luc]

Hi,

Originally posted by lightweight
LUC

If you look, you will find that some are ram TYPE Also, there is a few special subsonic ramjets that only need to go 100 mph, the better ones less

Yeap ... Maybe. But then, when those RAM jets get to higher speed, the flame holders can not slow down the air below flame propagation speed and you end-up blowing your flame front out. And they sure can not acheive supersonic speed.

Also, these slow speed RAM jets are very sensitive to inlet air speed changes. Just a litle crosswind in the intake and that's it ... Combustion's out or destabilize.

Good RAM jets are good and built for supersonic speed and works with the above figures. But if you want a slower one ... Heyyyy ... be my guest. But what's the point of having such slow speed RAM jet. You might as well get your hand on a good pulse jet or pressure jet.

You can also build a steam rocket you know ... But they never used them to go in space.

Cya,

Luc

[Bob Kelly]

well Luc the reason I started experimenting with a ram jet in the first place was its simplisity .... the use i had invisioned for it was for a helicopter
Jet tiped rotor ...
i built it way too small for that but i built it out of the meterial I had at hand
3" pipe to be exact... I tried a pulse jet but never did get a good seal for the reeds , I thought of makeing the entire cone a slideing valve to close off the explosion but that needed a lathe to make
which i don't have so I tried a few other methods of the valves but got busy with other projects and never got back to it .
I am courious as to the design of a presure jet that i could build for the rotor tips , to me they seam to have a carberator type inlet off to the side .. at least Vortech's do anyway ,
and that kind of makes my head hurt to think about that design ... it to ME just won't work.... because if the thing ever did ignite it would blow out the intake just as much as the exhost pipe ...
I realise the incomeing air is supposed to keep that from happening but I know what explosions do ,,,, they will defeet any deflectors you try to control them with ... at least thats been my experience ! <grin>
so how do you keep a fresh supply of air comeing into a pressure jet and keep it burning at the same time ?

there would be alot of folks useing jet tip rotors if they were realy available
started easy and actually worked !
the 20 pound ones on your site would probly do the trick I would think for most small single place helo's
but what do they cost ? it simply doesn't say anything about it
...
In the Avaition circles I have learned if you have to ask what it costs you simply can't afford it ! i fear its the same there as well
thanks for your input

Bob......

[Luc]

Hi Bob,

As for your interogations about the intake stack of a pressure jet, trust me, it works fine.

The stack work under 3 concept at once.
1) As a series of ejectors
2) A series of resonant tubes coupled together to maximize air pumping
3) The 3rd stage inlet tube is a diffuser and as you know, a diffuser slows down air and increase pressure

Now, take all thos 3 concepts, make them work together at the same time and what you get is a hudge air/fuel mixture mass under pressure inside the 3rd stage, which fights the combustion process.

You need to understand that a pressure jet breath, compress, burns and expell.

As it breath, the intake stack push the mixture inside the chamber.
As it compress, the intake stack block the compression for coming out.
As it burns, the intake stack block the combustion for coming out.
As the engine expells, its also start its breathing process again and the intake stack push more mixture in and the cycle starts again.

There is more to a pressure jet then the ruff explanation I just did. But ruffly, that how it works.

Look ... Our 20 lbs. presure jet actually generate 45 Lbs. of thrust, tested and prooven. So, obviously, the concept work very fine, or we would not try to build a buisness over it.

I can't say the same for the other pressure jets marketed on the Net today. But like I said, this will be history very soon.

Now, if you want pricing, please process your request trough our Website's contact page. But I will tell you, a pressure jet entirely built using SST-321, assembled, tested and certified is not cheap.

But if you consider the time and efforts you would put in building one, without any waranty it will work, the engine we sell are a safe and justified investment.

Anyway, bring your request trough our Website and we will see.

Cya,

Luc

[chaznc28607]

Ya know, I was thinking, been reading up on tip jet helicopters for a while, anything from the Hiller hornet, to peroxide fueled craft. Just wondering with the advanced electrical engines in ducted fans for RC craft. Would an electric ducted fan work better, even a prop motor.

I was thinking of laying tracks that a rotor spins on, connected to negative, and positive. Kinda like how toy electric train sets work, powering the electric fans, turning the rotors. Still in theory, me, and a bunch of friends sitting on our laptops think tanking stuff out.

Worst case you wouldn't want to be struck by lightning high up, but we believe it could be built as an ultra light, only need 20 pounds of thrust per rotor, and I am sure there are electric fan motors that can produce more then that.
And could be powered by a gas generator.
Ice breakers in the arctic use electric generators to power, electric motors all the time.
Let me know what you think?

[BBerson]

Ya know, I was thinking, been reading up on tip jet helicopters for a while, anything from the Hiller hornet, to peroxide fueled craft. Just wondering with the advanced electrical engines in ducted fans for RC craft. Would an electric ducted fan work better, even a prop motor.

I was thinking of laying tracks that a rotor spins on, connected to negative, and positive. Kinda like how toy electric train sets work, powering the electric fans, turning the rotors. Still in theory, me, and a bunch of friends sitting on our laptops think tanking stuff out.

Worst case you wouldn't want to be struck by lightning high up, but we believe it could be built as an ultra light, only need 20 pounds of thrust per rotor, and I am sure there are electric fan motors that can produce more then that.
And could be powered by a gas generator.
Ice breakers in the arctic use electric generators to power, electric motors all the time.
Let me know what you think?

The fan would have a significant gyro force to consider as it spins around on the rotor. But it might work.

[Dan Thomas]

Ya know, I was thinking, been reading up on tip jet helicopters for a while, anything from the Hiller hornet, to peroxide fueled craft. Just wondering with the advanced electrical engines in ducted fans for RC craft. Would an electric ducted fan work better, even a prop motor.

Worst case you wouldn't want to be struck by lightning high up, but we believe it could be built as an ultra light, only need 20 pounds of thrust per rotor, and I am sure there are electric fan motors that can produce more then that.
And could be powered by a gas generator.
Ice breakers in the arctic use electric generators to power, electric motors all the time.
Let me know what you think?

Several problems here: First 20 pounds of thrust, even if it worked, isn't the whole story. It has to maintain that thrust at something like 400 mph at the rotor tips. People with more skills in Physics can figure out the horsepower involved here. At any rate, the torque required to turn the rotor of a "normal" helicopter is enormous.

Secondly, the gyroscopic precession of the fans as the rotor turns will twist that rotor blade so much that it won't work. Don't forget that A helicopter's rotor blades are being repitched twice in a single revolution in forward flight, so that the mass of the motor and fan also has to change position. It's weight will resist that and cause enormous lag on top of the precession.

Third, electric generators and motors are heavy. Even high-efficiency stuff is heavy. That's why we find them in places like railroad locomotives and huge mine trucks and ships. Weight isn't a critical factor in machines like that, and is actually welcomed in locomotives, where traction is an issue, or in an icebreaker where momentum might be important. Airplanes and helicopters are a totally different animal.

Look around and see what's in common use. That's what works. There have been numerous attempts to use other technologies like electrics or hydraulics, but all of those just add weight, failure points, and efficiency losses. Direct mechanical drive is extremely hard to beat.


Dan

[BBerson]

What about steam jet? Just for liftoff, of course. The aircraft would need to convert into an airplane for forward flight because the water used for liftoff would provide for only a few seconds of vertical lift.

[Dan Thomas]

What about steam jet? Just for liftoff, of course. The aircraft would need to convert into an airplane for forward flight because the water used for liftoff would provide for only a few seconds of vertical lift.

We don't see any production helicopters using tip-driven rotors. None at all. That one thing tells me that it's been tried and found wanting.

Howard Hughes built a large tipjet-driven machine in the '50s, I think. It used an obscene amount of fuel and its range was only 40 miles. It was abandoned as impractical. There have been machines built using Gluhareff's jets but they aren't seen anywhere either.

Dan