[Diy_efi] Greenfire spark plugs... thought experiment

[Ernest Buckler]

you DID go to the Smart Plug website, right?  Same deal, except further 
complicated by lack of a timeable spark event!!!
Ernie



----- Original Message ----- 
From: "Mike" <niche at iinet.net.au>
To: <diy_efi at diy-efi.org>
Sent: Friday, June 24, 2005 7:23 AM
Subject: [Diy_efi] Greenfire spark plugs... thought experiment


> ok chaps,
>
> Here tis that simple thought experiment.
>
> Preface.
> This is not intended to prove the greenfire plug
> works better, its designed to illustrate pressure causing flow
> and how this can apply to ignition in a recessed plug. Nor
> is it to be taken literally, its indicative of the principle which
> I perceive has been glossed over by Adam Wade and I
> am hoping will go some way to articulate a reason for
> his unwillingness to accept there could ever be such flow.
>
> Whats interesting is once you think over this for a while
> and imagine whats going on with some interesting variations
> in tube design it might well suggest a mechanism to markedly
> improve operation, I'll leave that one for the entrepreneurs...  ;-)
>
> Steel tube 100 units long, say 10 units dia. Closed at position 0
> and plunger at position 100 where pressure is to be applied.
> Gas 'A' in position range from 0 to 50 and gas 'B' in position
> range from 50 to 100. Marked on position 30 where one might
> consider is approx position of the exposed end of the high voltage
> electrode. The closed end represents the 'blind' end which
> Adam Wade has remonstrated about and position 100 is the
> open end where gases move to and from.
>
> Now, move the plunger down to position 10.
>
> Q1.     Does the 'mix' line between gas 'A' and gas 'B' also move down
>        by same proportion ?
>        (rhetorical question - mostly ;-)
>
> Q2.     Is gas 'B' now exposed to the end of the high voltage electrode
>        at position 30 ?
>
> Q3.     If gas 'B' is combustible then will it ignite ?
>
> Q4      Can one extend the thought experiment for the converse side
>        when there is exhaust from the plug into the chamber following
>        (a possible) ignition  ?
>
> However,
> One thing that has me a tad curious is the issue of the overall
> efficiency and energy of the propogation of the flame front through
> the 5 or so peripheral holes - not just the gas, I see no problem with gas
> exit, but the actual flame front as I have little conception of the 
> relative
> velocities or depth of  thickness or speed of this flame front...
>
> ie.
> I understand there is a relationship between the hole
> diameter, its material temperature and the issue of pressure differential
> across the hole but I recall one safety issue regarding the davy
> lamp used in mines in respect of methane meant the flame
> front wouldnt propogate [easily]  through a small hole but would
> provide visible light, hence its safety value...From what I recall of the
> one davy lamp I held at school, the holes were less than 0.5mm, the
> holes in the periphery of the greenfire plug are maybe 4 times that etc.
>
> Does anyone know the particular relationship of flame front
> size for pressure gradient which allows the davy lamp to
> be relatively safe at 1atm yet allow this flame front principle to
> propogate through the peripheral holes of the greenfire plug ?
>
>
> Lets take it from there chaps, I got work to get on with...
>
> cyahs in a few days,
>
>
> Regards from
>
>
> Mike Massen
> Perth, Western Australia
> VL Commodore Fuse Rail that wont warp or melt !
> http://niche.iinet.net.au
>
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