[Diy_efi] Greenfire spark plugs... thought experiment, Adam ?

[Mike]

Adam,

Since you are still selectively posting <cough> ;-)

Did you not get this email ?

Do you have any observations ?

Has anything here made sense to you ?


Regards from


Mike Massen
Perth, Western Australia
VL Commodore Fuse Rail that wont warp or melt !
http://niche.iinet.net.au



At 06:23 AM 25/06/05, you wrote:
>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