turbojets

[BrokenBiker]

now, me an a mate are mulling over the idea of making a turbojet engine, more for a laugh than to power anything, although I can see it being bolted onto something with wheels at some point.

I know roughly what is needed for the build, we will be copying colin furze's build as used on the jet bbq, mainly as he shows the build being done, but he also shows the maths too, so for a first build its pretty straight forward.

now the bit that I need help with. furze shows a spark plug fitted to his jet, with the ignitors from a cooker to 'light' it. on other jets I have seen on youtube they just spin the inlet fan with a leaf blower and it seems to fire up.

now am I correct in thinking that as the air is dragged in at high velocity it heats up casuing combustion when compressed and mixed with fuel gas (propane in my case) or does there need to be a source of ignition such as a spark plug or flame to give the initial pop?

 

[doubleboost]

You need a spark
The blower just gets the turbine spinning
Once the burner lights up the expanding gas turns the turbine which drives the compressor which makes more gas to drive the turbine
It is the initial start that is the hard bit it is very easy to melt the turbine (been there many times)
There is a fair bit of gas turbine stuff on my youtube

 

[Rig Pig]

On a real turbine there is an igniter torch that is lit electronically that then lights the burner ring.

 

[doubleboost]

On a real turbine there is an igniter torch that is lit electronically that then lights the burner ring.

These are "real turbines" lol

 

[Rig Pig]

These are "real turbines" lol

Ah! I meant real as in produce useful reliable power!

 

[doubleboost]

Ah! I meant real as in produce useful reliable power!

lol

 

[CRB]

?Pulsejet?

Less complexity.

 

[atomant48]

Maybe try to salvage the APU from an old aircraft I think in the 60s there were a few car manufacturers tinkering with turbines which ended up serving as APUs.

 

[julianf]

two jets last weekend - one diy (which was made quickly, by someone who had never used a stick welder in their life before....) and a kit one.

unfortunately, the diy one did not fire, but the kit one was so loud! the size of your fist, and ear piercing...

i think it would be fun to build a turbo unit one, but i just cant work out what id do with it!

 

[julianf]

ps. igniter needed for start.

 

[BrokenBiker]

i thought i would need an igniter, rc glowplug might do it?

 

[BrokenBiker]

?Pulsejet?

Less complexity.

wrong noise...lol

 

[CRB]

two jets last weekend - one diy (which was made quickly, by someone who had never used a stick welder in their life before....) and a kit one.

unfortunately, the diy one did not fire, but the kit one was so loud! the size of your fist, and ear piercing...

i think it would be fun to build a turbo unit one, but i just cant work out what id do with it!

?What on earth lit up the tree to the left behind the grey/green belly? I think we would like to see that one.

 

[500e]

Melting a exhaust turbo is ok doing it on the real thing is real bad news "tens of thousands £/$" It was the thing drummed into me while learning,you have to have an igniter box it runs as long as you have finger on start button, at 60% N1 turbine becomes self sustaining

 

[KemppiFrog]

Maybe try to salvage the APU from an old aircraft I think in the 60s there were a few car manufacturers tinkering with turbines which ended up serving as APUs.

Rover made turbines (50s/60s). There are still a few fire pumps with them, hand start too. Then there was the Rover BRM Le Mans car and I saw one in a boat. I imagine all APUs on jets are turbines, just to use the same fuel.

500e. Mate had a very expensive hot start on his Bell 206.

 

[daleyd]

Rover made turbines (50s/60s). There are still a few fire pumps with them, hand start too. Then there was the Rover BRM Le Mans car and I saw one in a boat. I imagine all APUs on jets are turbines, just to use the same fuel.

500e. Mate had a very expensive hot start on his Bell 206.

Rover fire pumps were used as emergency fire pumps in the RN, you had to be careful where you stood when starting so as not to end up with your leg on fire. The noise in an enclosed space was phenomenal, usually towards the aft end end next to an external door.

 

[Cal]

I used to work at Rolls-Royce on gas turbines, you use an igniter plug until the turbune will self sustain.

A spark plug will do.