Electrical conductivity of flames (OT?)

[Bill Sloman]

We figured that we're 2 levels from the heads of state of Europe; we
slightly know Lisa Schlein. I used to work with her husband Peter,
physicist at UCLA/CERN... designed some CERN detector stuff for him.

Willy Brown knows everybody, like the Clintons and Obamas. We don't
actually know him, but Mo knows his kid, and she once broke into
Willy's Jaguar with a coat hanger.

Mo also knows a guy who used to work for Glenn Seaborg.

I've met Peter Alfke, Jim Williams, and Bob Pease, all gone now.

I met Barry Gilbert once - Analog Devices were running him around
their more significant customers, and Cambridge Instruments qualified.
John Larkin won't have heard of Charles Oately who pretty much
invented scanning electron microscopy, and had a bunch of graduate
students who made it work progressively better - I met him there and
two of the graduate students, Alec Broers and Graham Plows.

EMI Central Research was more fertile ground. I met Bill Percival, who
invented the Percival Distributed Amplifier back in 1936, Godfrey
Hounsfield who invented the brain scanner and C.A.G. Lemay who
invented the reconstruction algorithm which made it practical. I also
met the wireman who wired up EMI's first colour television camera - as
soon as he'd got the job done, and the camera had been shown to work,
the camera was dismantled again, in stages, and photographed at a
every stage, to document what he'd done. The guy was a genius wireman,
but not great at documentation.

 

[Fred Abse]

I met Barry Gilbert once

*Barrie* Gilbert.

 

[Bill Sloman]

*Barrie* Gilbert.

True. But he answers to Barry.

 

[George Herold]

I believe it is detecting the quasi random nature of the flame by
measuring its varying conduction.

--
Mike Perkins
Video Solutions Ltdwww.videosolutions.ltd.uk- Hide quoted text -

- Show quoted text -

Well at the risk of sticking my 'plasmonic' foot in my mouth again. I
think they are refering to a resonance at the plasma frequency.

https://en.wikipedia.org/wiki/Plasma_oscillation

But I could be very wrong. When I try putting in numbers (for the
electron density) I get frequencies in the 10^9 to 10^14 range... So
if the above link says that the resonance is in the kHz range... that
must mean very low electron density... (like 1 per cm^3?)
That seems hard to believe. But at low denisty the flame is not even
be a plasma.. so perhaps the above equations don't apply. Some
collective oscillation of the of the entire flame?

George H.

 

[Bill Sloman]

Flames are turbulent. If there is conductivity, it will be very noisy at low
frequencies, low audio range.

http://authors.library.caltech.edu/21398/1/223_Kumar_RN_1975.pdf

shows a few examples with quite obvious peaks in the acoustic spectral
output at frequencies up to a few kHz, but that probably has more to
do with the scale of the experimental set-up than the time-scale of
the processes amplifying the pressure fluctuations.