Re: The Freau number...

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Malcolm Watts" <m.j.watts@xxxxxxxxxxxx>

Hi Terry,
          You shouldn't have asked ;) .......

On 17 Jun 2005, at 17:55, Tesla list wrote:

> Original poster: Terry Fritz <teslalist@xxxxxxxxxxxxxxxxxxxxxxx>
>
> Hi All,
>
> With all this modeling stuff going on, we seem to need to solidify a
> constant...
>
> John Freau has this equation:
>
>          spark length (inches) = 1.7*sqrt input power (wallplug watts)
>
> That "1.7" seems to be a pretty important number given all this DRSSTC
> and streamer energy rise time stuff...  But that number changes
> depending on coil type and apparently Streamer Energy Rise Time (SERT)
> ;-)
>
> I would suggest the constant "F" as this:
>
>          Spark length (meters) = F x SQRT(bang energy x BPS)
>
> "F" would stand for "Freau" so John will be eternally famous!!  I
> would suggest going to meters just to keep things "scientific".  BPS
> would be assumed to be the optimal optimal number, but it should be in
> there since many have 50Hz power and the DRSSTC can have any BPS it
> wants...
>
> The units of "F" would be "meters / SQRT (bang power(watts))"
>
> John used "wallplug" watts but that is not quite fair for those that
> are running lights and fans ;-))  Bang energy is the energy on the
> primary cap at firing for a conventional coil or the input energy for
> a DRSSTC.  ScanTesla makes that easy to find now...
>
> Obviously, we would want to make our coils with as high of "Freau
> number" as possible...  "Freau" is fairly unique so it would not get
> confused with anything else...
>
> Comments, observations, thoughts, suggestions....??

A qualification is needed to apply John's equation, that being that
it describes the best you can do under certain circumstances. It does
not say that you will always get "x" sparklength for every possible
combination of E x BPS. To demonstrate by way of an extreme example,
it most unlikely that 0.1J x 10,000BPS = 10J x 100BPS in terms of
sparklength. What we are really running into are some inherent
characteristics of ionized air (a specific mix of gases) at some
specific ATP when stressed by some specifically tailored electric
fields. It appears to me that the "F" constant arises because of
these properties, sort of like other universal constants. Interesting
to think too that while there are questions in some circles as to how
constant some of those constants actually are (when considered over a
long time span), our "F" might also be subject to modification at
some finer level as the atmospheric mixture changes over time.

Malcolm