A small gas turbine with Axial Flow Compressor!

[Mike Everman]

OK, now I'm not comfortable helping. I'm trying to give you the benefit of doubt, but helping a Persian Gulf person make a power plant that only lasts one minute? C'mon.
I'm out.
This is NOT a weapons development forum!

[Arman_awn]

Mike Everman, What are you really talking about?
Did I say anything about WEAPON DEVELOPMENT?

Please do know this, The persian gulf people and of course IRANIANS were the people that led the world to nowadays level of development.
Remember "People in glass houses shouldn't throw..."
By the way, I want my engine to run only one minute for the first time, and I will increase time of operating on other tests.
I'm sorry I said something OFF TOPIC, and I prefer to return to the main subject of the topic, dear Mike.


Thanks,

Arman.

[El-Kablooey]

I think he meant that as a joke. A pretty funny one too. You should try to have a better sense of humor. Anyway, please put down your machine gun and chill out.

[Mike Everman]

I would never deny that the Persian gulf is the seat of civilization, nor do I suspect every middle eastern person I meet of being war-like. God knows, we Americans can no longer call anyone else in this world a war-monger with good conscience. You should know that most people here are shamed by our "foreign policy".

I apologize. You see, we may even be tested by our own government, to see if we will help a middle eastern person create a missile or cruise missile powerplant. For all we really know, what looks like a perfectly nice young Iranian jet enthusiast is really an American NSA agent testing our "patriotism". I wouldn't put it past our Homeland Security agency, come to think of it; they have a lot of money to figure out how to spend.

Good luck with your project. Turns out I'm not much help in this area anyway. ;-)

[NickC]

they have a lot of money to figure out how to spend.

since there is no such thing as social security anymore, they have decided to use the money to create robots that try to build axial flow gas turbines :D

[tufty]

Go on Ben.

Tell us how many IPs per week hitting the site resolve to .mil / .gov

:)

Arman. I personally would be very worried about using 1mm aluminium at significant speeds, especially cut and twisted disks. It's a grenade waiting to happen, as Mike says.

Doesn't mean it's wasted effort, though; you could use it to at least get a feel for what sort of performance a similar design in more "sturdy" materials might give by ducting it up, spinning it up mechanically to (say) 25% of expected rpm and measuring (from a distance) compression ratios. That would give you a chance to play with various duct configurations, too.

Getting anywhere near rated speeds would likely be a spectacularly destructive exercise, though.

Simon

[Arman_awn]

Dear Mike Everman,Ok, Ok, Now I know why you are not willing to help me in progress of this projetc.

Although WE Iranians also are always tested in order not to even interact an american, But BE SURE, this is our gov that is a war-base gov, not the civilized Iranians. Iran has been always known as the rising place for most of the great scientists. As you know, Dr. Firooz Naderi who is an iranian is head of NASA JPL or Jet Propulsion Labratory.
This is not our downside that our bad bad gov has intarduced us to the world as bad people. When the 1979 revolution happend and shah, one of the closest friends of USA, forced to get outta iran, our country never returned to that level of world respect. But do know that iranians are graetly seprate from iranian gov.

By the way, I'm an expert in aviation tech and also the jet propulsion, and I'm the writer for three country-wide published monthly magazines in iran. This project I just started, is only a researchive project and be assured, I will never develop something to kill people.


tufty, Thank you for your response. Now I'm aware of the risk of using 1mm Aluminium for the compressor blades. What metrial do you suggest?

Thanks,

Arman.

[Mike Everman]

Welcome to the forum, Arman. I meant I do not have any experience with turbojet building, being a valveless pulse-jet man. You sound like a fascinating character, and I would like to start over.

[Arman_awn]

Dear Mike, You've just pointed to the thing I wanted to mention.
Im here, You're here to be together, to help each other.

Im not interested in pulse jet engines, but primarily I wanna thank you for your help.

I'm going to build the turbine wheel out of 5mm Iron sheet. What is your opinion about that?

thanks,

Arman.

[NickC]

from what I've read on axial compressors, you'd probably need something more like titanium or inconel. A high strength steel would atleast be better than aluminum, i'd stay away from iron though. If you can find titanium or inconel it will be your best bet.

[Anders Troberg]

Correct me if I'm wrong, but isn't the server owned and operated by a Danish citizen?

In that case, current US policy may at the very most apply to members who are US citizens. Until anything else is proven, I trust the word of Arman_awn when he assures us that it is not for military use. I have lived long enough in the middle east to know the great value placed on honesty there.

It's an interesting project, and I'd love to see how it turns out. As others have said, be careful about the aluminium. It's difficult to see from the images, but it looks like you've cut it from sheet metal and twisted the fan blades. Is this made by hand, and in that case, how exact is it? Is it properly balanced (not just weight, each blade must also provide the sam pull)? Imbalances here could greatly reduce the risk of spectacular failure.

[tufty]

It's an interesting project, and I'd love to see how it turns out. As others have said, be careful about the aluminium. It's difficult to see from the images, but it looks like you've cut it from sheet metal and twisted the fan blades. Is this made by hand, and in that case, how exact is it? Is it properly balanced (not just weight, each blade must also provide the sam pull)? Imbalances here could greatly reduce the risk of spectacular failure.

I'd like to know that too. Also, how were the blades cut? if not through something like laser cutting, there's a good chance of additional cracks and stress fractures, especially at at the blade roots, which would be a bad thing. Even more so if the blades have then been twisted to shape. Just the centrifugal forces of spinning it at 100,000+ rpm are going to load it massively, and then there's the "pull" of the blades to consider.

Simon

[Arman_awn]

Thank you all my friends for your responses,

I know that the load on the blades in 100,000 RPM will damage them, because they are made from 1mm aluminium, but isn't it possible to run the engine at lower RPMs(15,000 or 20,000 RPM)? Please be aware this engine is being prepared for very very basic tests only, I'm not aiming at reaching the max thrust. Tell me wether it is possible to run the engine at 20,000 RPM using this hand-cut 1mm aluminum blades or not.

I've said somthing about the turbine wheel. I wanna build the axial turbine wheel from 5mm iron sheet. When the turbine wheel is ready, I will prepare the turbine blades (made from 3mm iron sheet) and I'll weld the blades to the wheel. Inform me if there is somthing wrong with my plan.

Thanks,

Arman.

[NickC]

go ahead and build it, but put maybe a little box of polycarbonate around it incase i blows up or make the walls of the engine sorta thick in case it grenade. No one really tests when an obviously improperly built engine will blow up though, so you probably wont get an answer...

[Anders Troberg]

You can probably get a rough idea if it's balanced or not by spinning it up using forced air. Any vibrations means that you need to balance it better. What you feel as a vibration at 1000 rpm will make it tear itself apart at operating speed.

I've said somthing about the turbine wheel. I wanna build the axial turbine wheel from 5mm iron sheet. When the turbine wheel is ready, I will prepare the turbine blades (made from 3mm iron sheet) and I'll weld the blades to the wheel. Inform me if there is somthing wrong with my plan.

Frankly, I think you'll have huge problems getting the needed precision. It's too early in the morning for me to do the math, but sufficient to say, even the smallest imbalance or assymetry in the blades will cause extreme stress at 100 000 rpm.

The best way to do it is to find someone who has the machinery needed to cut the entire turbine from one piece of metal in an automated process. I suspect that's the only way to get the needed precision.

If the thing blows up, most (but not all!) of the shrapnel will be thrown sideways or backwards, so keep in front of it and try to keep a healthy distance until you have made enough test runs to trust it. Run it outdoors, as there will be less surfaces that will cause ricochets that will throw shrapnel all over the place.

Take care, you can always build another engine if you don't feel certain that it will be safe, but you can't go back if you run it anyway and end up dead.