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Igniter Testing

PostPosted: Sun Sep 06, 2009 6:17 am
by Iain
Just started testing of our LPRE igniter, picture attached (hopefully) and youtube video here,
http://www.youtube.com/watch?v=NHx7x9CGsNE
Got some mods to make before we test again but expect V1.5 soon!!

Iain

Re: Igniter Testing

PostPosted: Mon Sep 07, 2009 1:50 pm
by pauldear
Nice one! Can you explain what it's doing (for dumbos like me)?

Re: Igniter Testing

PostPosted: Tue Sep 08, 2009 6:13 am
by Iain
The concept is pretty much a tiny rocket motor to light the larger one!

I used GOX and Propane ignited by the sparkplug, I had a few issues though which as you can see in the video looks like more a series of little explosions rather than sustained igniton.
My fuel/ox oriffice sizing was too big and was blowing out the fire, so to speak,so would only ignite when the sparkplug fired, I think the impingment might have been abit off as well, and my sparkplug was not pulsing enough, I had it hooked up to an electric fence unit, was abit slow. So next test, smaller oriffices, faster pulse and see what happens!
If not I got another design which I'll machine up over the weekend which should work for sure anyhow!!

Should be exactly like this (Masten) next time I try!
http://www.youtube.com/watch?v=AzFPvko1 ... annel_page

Stay posted!!


Iain

Re: Igniter Testing

PostPosted: Tue Sep 08, 2009 8:58 pm
by pauldear
aha - now it all makes sense! Thanks. And keep up the good work on the photos too.

Best,
Paul

Re: Igniter Testing

PostPosted: Sat Sep 12, 2009 10:26 am
by Iain
Just tested again tonight, 100% successfull, although a little on the ox rich side.

I'm happy, picture below, video posted soon....


Iain

Re: Igniter Testing

PostPosted: Sun Sep 13, 2009 9:25 am
by Iain

Re: Igniter Testing

PostPosted: Sun Sep 13, 2009 6:39 pm
by pauldear
Oooh - if there's one thing I like more than flames, it's engineering that works. It looks good.

What's the nozzle made of, and what temperatures will it take? How long will it need to fire for?

Re: Igniter Testing

PostPosted: Wed Sep 16, 2009 11:26 am
by Iain
Thanks!

The entire thing is made from a solid bit of Stainless rod that I machined out, its only designed to fire for about 2sec, to keep it below the melting point of SS as its not cooled and just long enough to ignite the main propellants and then shut off.
It can take a fair bit of heat as you see in the video, SS melts at about 1500 Deg C so its getting fairly well up there for acouple of seconds but not long enough to do much if any damage........hopefully!


Iain

Re: Igniter Testing

PostPosted: Mon Sep 28, 2009 12:06 pm
by Peter (Nebula)
Hi Iain

Sorry, I meant to post earlier but I got sidetracked. Nice videos :)

One of the things that gets demonstrated very nicely here is just one of the problems that has to be overcome when miniaturising engines, ie. thermal management. I know this is an igniter rather than a thruster, but it does show up what happens when the phsysics and temperatures stay the same but the radiative surface area decreases.

The injectors you're using look like they're from a Nox system - have you cannibalised a car? ;) Looking forward to comparing engines!

Best

Peter

Re: Igniter Testing

PostPosted: Tue Sep 29, 2009 1:40 pm
by Monroe
Holy Cow! Way to go Iain! Hey, thay make a 2-stroke spark plug called a surface gap that you may like? An ingniter circut from a home heating unit (furnace) may provide a cheap soultion for a higher power long duration start? If your interested in some ideas? Good Work! Go Kiwi!

Monroe