Worklog: 8MadDog8's DIY Gas Turbine

[LostBenji]

More holes and better spacing in the combustor can. Not enough airflow to the gas (fuel) mixing area.

The idea of the holes in the combustor can is to spread airflow but also to keep the flame off the walls. Flame on walls equals excessive heat soon followed by liquid metal blowing through the rather old and rough turbine.

Spiraling the airflow heaps reduce hot-spots.

This is basic and rude but may help.
http://www.8051projects.net/jetengine/page2.php

Now look at this:
http://www.maruwa-denki.co.jp/en-service03/index.html
and see the large holes then take note of the smaller holes, these keep the flame off the walls.

http://www.enginehistory.org/G&jJBro...way%20view.JPG

http://www.enginehistory.org/G&jJBro...%208%20can.JPG

Keep the flame off the turbine wheel also or certain death will follow soon after.


Have fun.

[Carcin0Genic]

Is it just me or are there no pics?? The layout of the text looks like there should be pics.....

[abadonn]

I used to work on Gas Turbines. Ah... combustion cans... old memories. The idea being that the flame inside the can is encased in an outer layer of cooler air so it doesnt burn through the side. Cos if it burns through the can of an aircraft engine you get things like the Manchester tragedy http://en.wikipedia.org/wiki/British...urs_Flight_28M. However I'm not sure whether you'll have quite the same degree of temperature inside that can due to lower compression ratios from the compressor area.

The 1st stage Nozzle Guide Vanes (NGVs) were the first bit of serious metal to be hit by the combustion flame and were the toughest part of the engine, they were used to direct air onto the 1st turbine stage. Essentially you couldnt make an engine run hotter than the NGVs could cope with, they were the limiting factor heat wise. In operational aircraft the EGT (Exhaust Gas Temperature) at the exit from the engine would increase over time as the turbine blades and NGVs slowly deteriorated. Once it got to a certain level the engine had to be overhauled regardless of its operational time. In this engine theres quite a bit of distance betwixt flame and turbine, less efficient I suspect but much thermally safer for the turbine.

ITs a great project. dont forget to video it when you start it up. I assume guys with home turbines have said the can will survive ok? Cos its prob not made of the same stuff engine cans/chambers are.

[Shepete]

Originally Posted by Reaper_1994

Keen to see what it's used for. SUBBED!!!

For turning fuel into noise, of course. You need no other reason.
I have always had a hankering for "Pulse" jets. Never got around to building one though.
Very, very nice work. I look forward to seeing the end result.

[Davo1111]

Originally Posted by Carcin0Genic

Is it just me or are there no pics?? The layout of the text looks like there should be pics.....

you might have blocked tinypic?

yes there are pictures

[LostBenji]

Originally Posted by abadonn

I used to work on Gas Turbines. Ah... combustion cans... old memories. The idea being that the flame inside the can is encased in an outer layer of cooler air so it doesnt burn through the side. Cos if it burns through the can of an aircraft engine you get things like the Manchester tragedy http://en.wikipedia.org/wiki/British...urs_Flight_28M. However I'm not sure whether you'll have quite the same degree of temperature inside that can due to lower compression ratios from the compressor area.

The 1st stage Nozzle Guide Vanes (NGVs) were the first bit of serious metal to be hit by the combustion flame and were the toughest part of the engine, they were used to direct air onto the 1st turbine stage. Essentially you couldnt make an engine run hotter than the NGVs could cope with, they were the limiting factor heat wise. In operational aircraft the EGT (Exhaust Gas Temperature) at the exit from the engine would increase over time as the turbine blades and NGVs slowly deteriorated. Once it got to a certain level the engine had to be overhauled regardless of its operational time. In this engine theres quite a bit of distance betwixt flame and turbine, less efficient I suspect but much thermally safer for the turbine.

ITs a great project. dont forget to video it when you start it up. I assume guys with home turbines have said the can will survive ok? Cos its prob not made of the same stuff engine cans/chambers are.

Throw them some Inconel to play with....

[grrrr]

Originally Posted by Reaper_1994

Keen to see what it's used for. SUBBED!!!

look at the first websites listed..

here is a couple of jet karts powered by these jet engines.

http://youtu.be/rYDfP2uY500

[whirlybomber]

Originally Posted by 8MadDog8

Hmm 150NB pipe, 8mm plate, all fully welded, think it has a safety factor of 1000 haha
But isn't the key to being an engineer to over engineer everything

Rule 37 covers this perfectly.

[MADMAX]

man ive been wanting to build one of these for years, got right into all the info collecting a few yrs ago but got no further, now I work on a mine site and can get hold of old big ass turbos off of 20 to 100 ton dump trucks might be time to get back into to it again....

this is what you will do with it once it is complete

http://youtu.be/JE4t-o7XY6M

jet powered gokart

[Westerntribal]

It will be soooo awesome the first time you fire that thing up. I want to see that shit. Video it....please

Actually how are you going to fire it up?.. I can't wait to see this !!
If it works you could add another turbo to the exhaust gas port, and run a shaft off it to some crazy elaborate setup that generates electricity to power a pc.

[Shepete]

Originally Posted by Westerntribal

If it works you could add another turbo to the exhaust gas port, and run a shaft off it to some crazy elaborate setup that generates electricity to power a pc.

Be about as efficient as running a coal powered power plant to run a cell phone.

[IMtech]

Originally Posted by Shepete

Be about as efficient as running a coal powered power plant to run a cell phone.

Huh... Isn't it already what is done currently in OZ, except that they lower the voltage to 220V then down again via the phone's charger?

[kryzak260]

Originally Posted by Westerntribal

If it works you could add another turbo to the exhaust gas port, and run a shaft off it to some crazy elaborate setup that generates electricity to power a pc.

If you were going to do this, you would just attach the generator shaft to the shaft of the current turbo rather than run another turbo off the exhaust gas.

That is how LM6000s (aero derivative of a GE CF6-80-C2) hook it up. In the states, with 60Hz power, they hook the genny straight up to the low speed shaft, which spins at 3600RPM. In Aus, they have a reduction gearbox in-between, to gear it down to 3000RPM for 50Hz power. Air temperature, air density and availability of SPRINT dependent, this will net you between 41 and 48 megawatt...

A bit of useless info for you today

[Westerntribal]

LM6000 is a turboshaft. It has a freespooling compressor(s) attached to a seperate powershaft which is spun by the exhuast gas of the main compressor or turbine?

Anyway... god I want one of those go carts. With a afterburner !
Fucking brilliant

[kryzak260]

Originally Posted by Westerntribal

LM6000 is a turboshaft. It has a freespooling compressor(s) attached to a seperate powershaft which is spun by the exhuast gas of the main compressor or turbine?

Yeah, dont mind me. It works how you proposed he set this model up. The HP Turbine and Compressor are on a single shaft (~10,500 RPM at full load) and the LP Turbine, Compressor and the Load are driven off the LP shaft which runs through the middle of the HP shaft.

*Thou shalt not post on the intertubes after 10 beers haha