just some thoughts on stans wfc concentric tubes:

the inner and outer tubes have the resonant electrical frequency of the series inductor capacitor ( water) hitting them. So zero to max voltage on each tube ( positive on one tube/negative on the other). You want one tube to be hitting minimum voltage at same time as other tube is hitting max voltage....so synchronising the ringing inductors on each side of the wfc. So one inductor is variable to get the same resonant frequency on both sides of the wfc.....but....
 
Question: Is getting the same resonant frequency on both sides of the wfc enough to get  the max/min voltages synchronised on each side of the tube at  exact same time...?

Also just a thought : why stan had notches on some tubes:
Each inner and outer tube will have its own resonant vibrational frequency ( acoustic), hit each tube and it will ring acoustically with a certain note, like a guitar string.
 The inner tube will have a different frequency to the outer tube. Stan might have been trying to give the inner and outer tubes the same acoustic resonant note.

What would be typical frequency of each tube? I have no idea...will it be in the khz range where stan had his electrical ringing frequency?

I doubt the vibrational ( acoustic ) resonant frequency has to match the electrical resonant frequency of the inductor/capacitor electrically ringing circuit. It doesn't seem to play any role in the injector wfc ( there doesn't appear to be any attempt to get the inner/outer cone shapes of the injector wfc to be matched acoustically).

I think it may have been more experimental in nature rather than something that proved to be important.

Is there any advantage , to match the acoustic resonant frequency of the wfc ( tube or injector) to the electrical resonant frequency?
My guess is its not important, if you could match those frequencies the wfc tubes should make quite a noise, the same should apply to the injectors also. Really I have no idea if its important or not, my guess is it the electrical frequencies that are important and the acoustic frequencies are irrelevant......I could be wrong.

Human hearing  goes up to about 20khz which is certainly in the range where stan was pulsing,  what sort of frequency do the stainless tubes of lengths stan used resonate at?
If its in the 10-20khz range then maybe there is some value in matching acoustic/electrical
frequencies?

here you can hear 10-20khz range....find where your own hearing cuts out.......i hear nothing at 19khz

https://www.youtube.com/watch?v=00y198cE-IU

here is 10khz note

https://www.youtube.com/watch?v=_GQlAbM7NK8

anywhere near stans wfc tubes?

the water misters use about 1.6-1.7mhz to make small droplets of water mist.

The water injectors would have much higher frequency if its important at all. Do the inner and outer
portions of the injector wfc ring at the same note?

Something I didn't understand about series resonant circuits, at resonance the voltage drop across the inductor is zero. So I assume the 200omhn resistor stan uses in some circuits becomes the current limiter?
Circuit dia from this article
http://www.electronics-tutorials.ws/accircuits/series-resonance.html
( it has some examples for calculations at bottom of page also)

there is some discussion on this page
http://tesla3.com/free_websites/wf_meyer_ravi.html
which suggests 5.65khz is acoustic resonance for 12.5 to 13cm long tubes ( calculations wont be 100% accurate as its concentric tubes
not just a single tube.
It is also reported that dave lawton got best gas production at 5.7khz, near the acoustic resonance of the tubes.
So there might be some value using acoustic resonant frequency of the tubes ( matching to the series inductor/capacitor circuit ringing freq)

I realise alot has been discussed about acoustic resonance of stans tubes here and on other forums.
Somethings of interest: some organ pipes are tuned using a vertical slit, the slit removes that portion of the tube from the resonant vibration ( harmonic) and increases frequency by effectively shortening the tube.

resonant freq of tube closed at one end is
f = v/4L
f=freq v=vel in water L=length of tube

from http://www.uq.edu.au/_School_Science_Lessons/UNPh26.1.html

calculating using data from stans estate, for electrical frequency of his series LC circuit:
using  f=1/ ( 2pi*sprt(L*C))
f=resonant freq, L=inductance of coil, C=capacitance of water tube
( data: @100hz L=0.607henries, C=24.85microFarad)(from dynodon data)
Gives f=41Hertz
So if my calcs are correct stan was pulsing at around 41hz ( that seems very low)

( forgot stan had 9? tubes in series, so my calcs are a bit out)
adding together capacitors in series using correct formula gives:
1/totalC=1/c1+1/c2...etc
gives
1/totalC= (1/24.85)*9=0.362
totalC=2.76microfarad
freq=123hz
( perhaps the data i used has some problem? ) or there is some other error i'm not aware of, the resonant frequency seems extremely low. Perhaps the 200ohmn resistors stan used need to be taken into account?

for stans inner tube:
length=13cm
velocity=1484m/s (sound in water)
f=v/4L
f=2.853khz (res freq)
previously calculated electrical freq was 41hz, seems very different values.
( I suspect my 41hz value maybe something wrong with the calculations or data used)

seems there is another acoustic resonance inbetween the tubes,  calculated using closed end tube formula ( 1/2wavelength for 1st harmonic), gives 370khz according to this post ( for 2mm gap)

https://groups.yahoo.com/neo/groups/meyer_wfc_replication/conversations/messages/3806

so if resonance acoustically plays a role, how would you determine the resonant acoustic frequency of the injector? That might be quite difficult.
You can use a mic on a computer and a program to find resonant frequencies of objects.
This video shows a computer program that can be used

https://www.youtube.com/watch?v=2DUTnLv3z6U
there is a free demo version

But the injector once screwed into a car engine block, might change its frequency.
The inner cone shape in the voltage zone, might be possible to find its frequency using some formulas, its pretty close to a cylinder for which formulas are on the internet.
The inner cone might act a bit like a tuning fork end.

with regard stans injector:
memo6 and 8
( last pic on bottom of thispage
http://tesla3.com/free_websites/wf_meyer_lawton.html

clearly shows the voltage zone as an 'electrical waveguide'. There seems no mention of acoustic resonance. I'm guessing stan messed around with acoustic resonance in the tubes, but not releveant in the injectors.....I could be wrong).,
So if stan is claiming the injector acts as an electrical waveguide, it would mean a very short wavelength is required, which does not seem to be the case. Its an open ended waveguide, which would mean 1/4 wavelength as first harmonic. I forget the exact length of the cone in the voltage zone, but lets say its 5cm and the electrical waves travel at 0.11vel factor in water (using vf=1/sqrt dielectric constant)
and chromium coating on t304 dielectric constant of 30 gives vel factor of 0.18.
So the water and the stainless coating have similar velocity factors ( if my calcs are correct).
Theres not a huge refractive index from ss( coating) to water.
Anyhow:
So lets say you want a wavelength of 1cm for example ( close enough to 1/4 wavelength for the length of the cone in voltage zone)
then freq=vel/wavelength
freq = 0.18* speed of light/ 1cm
freq = 54,000,000,000 or 54ghz
way way way off stans frequencies.

So that doesn't work.
What if we use 1/2 wavelength across the gap in the voltage zone ( closed cylinder) ( 0.01inch gap) 0.01inch =  0.254mm
then 1/2 wavelength would be 0.127mm
then freq = 0.11*speed of light/  0.127mm
freq = 259 ghz
even more outrageous!

So electrical waves to be bounced inside the waveguide ( as stan illustrated) would need to be extremely energetic waves, way above the khz range that stan was using. I would guess the diagram is more symbolic than accurate. He also shows the waves passing out of the injector into free space, I have no idea if that is what occurs. Accelerating electrons do give off em radiation, Its a bit beyond my understanding.

From all this rambling I have found what might be a useful article in some way:
I've read that stans tubes might have had a chromium coating??
Well here is an article that goes in depth into chromium coatings on t403 stainless steel.
in you put below into google it will come up ( couldn't figure out how to put direct link)
URN_NBN_SI_DOC-EH3EEAPC.pdf

I think the skin effect in metals would mean most of the voltage pulse is concentrated on the outside of the metal, which would mean the chromium layers velocity factor maybe more relevant than the stainless steel itself.

 

I think my calculations in last post might be ok, I've found some info on stub resonators,
https://en.wikipedia.org/wiki/Stub_%28electronics%29

which shows some cylinderical resonators, at a length of 12.5cm ( close to stans tubes)  requires a resonant frequencies of 300mhz and thats at 1/8th wavelength.
Stans tubes are concentric but it does suggest much higher frequencies than stan was using for the tubes to act as waveguides.
So how to reconcile khz wavelengths of stan and the idea the tubes act as waveguides?

looking at coaxial cable vel factor, it seems the dielectric between the metals limits the speed of the wave,. So possibly for stans tubes its the water vel factor of 11% gives more accurate speed of the electrical waves in the tubes.

I'm puzzled by stans drawings of the injector as a waveguide, his images show a change in frequency of the wave along the tapered waveguide. A bit of research showed that frequency remains contant in a wave, and requires to be changed at the source of the wave( its the wavelength and speed that can be changed, frequency is pretty much a constant........try and think
of some example that break that rule?)
Under what circumstances can a waves frequency change? I could only think of the doppler effect, where its the relative motion of observer/object that causes a change in frequency,
That led to an interesting find:
an acoustic-opto modulator
https://en.wikipedia.org/wiki/Acousto-optic_modulator

So lets assume that stans low frequency pulses ( 5-20khz), do in fact  cause an acoustic resonance. An acoustic wave is exactly what is required to cause a frequency change. So could it be possible there is an interaction between the acoustic waves and the electrical waves which might shift frequency?
Is this also occuring in the tube wfc, since acoustic waves can be used to change frequency of other waves ( similar to doppler effect).

I also have some issues with stans diagrams of the injectors showing the waves propogating out of the injector ( he shows them as linear, compressional or expansive). If the electrical wave is producing VLF radio frequency waves, they would come out of the tubes or injector at right angles direction of the electrical wave, not continue in the same direction out of the injector.
If the waves he is referring to are electrical waves with a frequency shift due to acoustic waves interacting with them, then the diagram might start to make some sense.

I'm of the opinion a wave is a wave is a wave.........they all work with the same principles......
beach waves, electrical waves, optical waves, terahertz waves.....what works with one type can  be applied to the other type.

.

did a search for electro-acoustic resonators ( nothing ), but did find an article which does have some experimental results for such a phenomenon.
this link:

https://books.google.com.au/books?id=HcqOOfh6DX0C&pg=PA110&lpg=PA110&dq=acoustic+modulation+of+electric+wave&source=bl&ots=lS36loKvvI&sig=7FTrjkny5tNJKZhBLdZ2ql4CyEo&hl=en&sa=X&ved=0ahUKEwj-o5iwurXKAhVlE6YKHYwgC9U4ChDoAQgaMAA

or you type in
acoustic modulation of electric wave
into google
go down to the link starting:
Electromagnetic Material Interrogation Using Conductive.....
byBanks, Buksas and Lin
It will take you to google books link, to the experiment. I haven't read it in detail yet, but seems the effect is real.

i read the link abouve, its more concerned about acoustic waves effecting the bouncing of an electric wave off a material,  and the depth the electric wave crosses into the material, not very useful probably. But it does confirm there is an effect of acoustic waves of propogation of in an electric wave.

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

electrophoretic depostion, has some similarities to stans setup.
example
https://www.researchgate.net/publication/261384287_A_Current_Opinion_on_Electrophoretic_Deposition_in_Pulsed_and_Alternating_Fields

I've been thinking why would the electric pulse cause the tubes to vibrate, I couldn't find anything of use where the stainless steel would cause the vibration. But water does expand and contract and reacts strongly to a high voltage field.......it might seem obvious to some.....but its the water that is causing the voltage pulses into vibrational pulses.
there are many examples of water changing shape due to high voltage fields, here is one:
http://www.sciencedirect.com/science/article/pii/S0009250915000925

an advanced version of kelvin water dropper
http://www.rsc.org/images/loc/2014/PDFs/Papers/053_0326.pdf

an interesting paper on pure water between metal plates ( at very small scale with low voltages) studying the movements of ions in pure water due to the electric field.
They found that the electric fields produced by the movement of ions could be larger than the voltage of the applied field.
http://rspa.royalsocietypublishing.org/content/468/2137/18

another interesting article, concerning the bending of a stream of water near a charged rod ( or similar)
http://pubs.acs.org/doi/abs/10.1021/ed077p1520?journalCode=jceda8

Although I haven't found a pdf on the net of the whole article, the authors experiments were to determine if the high voltage electric field was acting on the polar molecules within the water.
There results are surprising, they claim its charged droplets in the water stream which are attracted or repelled by a charged rod. Without those charged droplets there is no deflection of the stream. Which seems to be not in agreement with stans theory to some degree.

Heres another experiment that supports the previous article, which shows a very high voltage potential has hardly any effect on liquid water surface. So it would seem formation of droplets is quite important in bending a water stream. I'm not sure how it relates to stans work though.

https://www.researchgate.net/publication/263006459_Electrostatic_Deformation_of_Liquid_Surfaces_by_a_Charged_Rod_and_a_Van_de_Graaff_Generator

an interesting paper on short duration electrical pulses and formation of pressure waves in water
( the paper is about how membranes on cells become damaged due to electric fields).
The last paragraph in the discussion section is particularly interesting ( seems to support stans theory of water splitting).They were using pulses around 1000v in nanosecond time scale, very short duration, and measuring the pressure waves produced in various mediums ( water based).
The pressure waves had approx speed of sound in water, but were very high frequency ( mhz).
http://www.nature.com/articles/srep15063

speed of sound in water decreases when bubbles introduced into a tube,
in this experiment in a water filled tube, speed decreased by 1/3.

https://repositories.lib.utexas.edu/bitstream/handle/2152/31138/SpeedOfSoundBubblyLiquids.pdf?sequence=1