Re: Sparklength inquiry

To: tesla-at-pupman-dot-com
Subject: Re: Sparklength inquiry
From: Greg Leyh <lod-at-pacbell-dot-net> (by way of Terry Fritz <terryf-at-verinet-dot-com>)
Date: Fri, 25 Sep 1998 17:39:57 -0600
Approved: terryf-at-verinet-dot-com

> Original Poster: "John H. Couture" <couturejh-at-worldnet.att-dot-net>

>   Power Input     JohnF    JHCTES
>   680 W           42"      15"
>   2100 W          64"      35"
>   8400 W          128"     97"
>   10 KW           15'      9.3'
>   26 KW           25'      18.3'
>   33.6 KW         21'      23'
>   67 KW           31'      38'
>   109 KW          45'      55'
>   134 KW          42'      64'
>   538 KW          84'      180'
> 
>   Note that both curves cross at about 33.6 KW with a 21 and 23 ft spark
> length. The streamer sparks are longer below this level and shorter above
> compared to the controlled sparks. The JHCTES data is from the computer
> program and the Fig 2 graph in the TC Design Manual. This graph is based on
> power levels to only 60 KW and has been extended to higher power levels
> without actual test confirmation.

Just curious, what were the specs on the 60kW coil?


>   It should be noted that the square root curve flattens out and ends up
> with very little increase in spark length regardless of power input. This
> would make a lightning bolt a couple miles long almost impossible? The
> average lightning bolt has about 150 joules of energy.


150 Joules???!!!  Perhaps an umbrella is all you need after all!

See Page 215, 'Lightning', by Uman.  
The typical energy in a strike is approximately 100kJ/m.
Therefore a 2 mile strike would therefore dissipate about 
_322 MILLION_ Joules.

I'm beginning to think that this thread is 'flame bait',
and so I will bow out at this point.  The book is very
good reading, you should pick up a copy.
-- 


-GL
www.lod-dot-org