T-Pain Is On A Boat: Re: [Electric Boats] Innovation and Resonance

Hi Roger

- Software is only as good as the person who programmed it as it doesn't reach it's answers by it's own real world experiences but only those of others, sound familiar?

- I used to work for an overseas division of Pentair years ago and we were given software to use from a University somewhere in the USA, and while it was good at predicting/modeling the "usual" stuff it was a bit hit and miss on the more unusual e.g. a head of air somewhere in the system that compressed and expanded giving odd pressure readings that come and go etc.

- When we had a factory situation where a 1.5mm wall stainless pipe was neatly split open 300mm from a bend, it had no idea, as nor did we at first. We put pressure transducers in a few places, changed pump impellers and generally shuffled our feet. It wasn't until we were lucky enough to be there when a 3-way valve was changed over that we stood and watched (didn't need the transducers) as the pressure wave in the pipework got stronger and stronger until the whole 6 meter length we were looking at was physically moving in it's brackets. Someone sprinted to the valve and changed it back and it disappeared. That was not a slam shut valve, as it was operated by hand and was quite stiff so was impossible to slam it shut and create a water hammer situation.

- Long story short an arrester in the system would have to have been pretty big, but my boss who'd seen most everything made what at the time seemed a bit naive but in hindsight was the best option, simply change the length of the pipe run, move a bend or in some other way change the geometry or mass of the flow, We re routed the pipe work and shortened it by around a meter and that was the end of that.

- The software (USD$15K from memory) was as oblivious afterward as it had been before.

- I have also tried software modeling of the parallel resonant tank circuit used in Inductive heating but again it's limitation seemed to have be humanly imposed, i.e. it's a common misconception that the minute you try to use or extract energy from a resonant circuit the oscillations die away and so the power input need rises in proportion to the output power used.

- This may be the case if you were passing tank circuit current through an external circuit, but in the case where the tank coil is the "work coil" and acts as a transformer primary, very real power can be used to heat/melt metals close coupled to and acting as that same transformers secondary.

- The "work" done to heat a given piece of metal depends on many many things, e.g. coupling, metal type, metel geometry, operating frequency etc etc, but if even only moderate care is taken, heating levels/speeds 5 times those that can be achieved with resistive heating drawing the same current at the same voltage are easily obtained. I can't remember if the software I used was Tina or Labcenter (it wasn't mine and it was a year or two ago) but it in no way accurately represented what we were watching happen in the real world.

- I'm not sure how modeling software is written, I would expect true AI modeling is still a way off and not considered accurate enough for engineering, so it is currently based on someone's real world experiences, which as we should know there is precious little of any more. So we could well be using software that is based on zero empirical knowledge, how wonderful.

- So everyone is now learning from people with little to no empirical knowledge, using software written by people with little to no empirical knowledge.

- It reminds me a little to much of Rudyard Kipling's Bandar-Log "We all say so, and so it must be true"

Cheers, Julian

On 23 May 2013 16:59, Roger L <rogerlov@ix.netcom.com> wrote:

Julian, I agree with a lot of what you say about the importance of not ignoring innovative solutions. And agree that way too little has been done with operation at resonance. But is that necessary anymore? With today's computers and free programs anyone can solve resonance problems overnight.

This is innovative intellectual freedom of the best kind!!

A BIT ABOUT MATH:

Resonant mathematics exist and are quite well understood. The mathematics of resonance used to require a lot of study, although the path to that understanding was well known even a hundred years ago. Now a home computer running inexpensive programs that will solve resonant problems in dynamic systems quickly and simply. Today anyone with a good or better high school education can set up and let the computer solve resonant problems overnight......the same problems that just 20/30 years ago required a year of Ph.D. time.

Yes, you are correct that there is no symbol for resonance in traditional calculations. There couldn't really be a symbol for it because mathematical resonance isn't something that exists by itself. It is simply a special condition that exists throughout a set of answers when a differential equation describing a dynamic system is solved for frequency. There is no single solution. What happens mathematically is that sometimes a portion of a dynamic solution set "blows up" in one energy realm or another and that is what is popularly come to be called "resonance".

A SITE WORTH LOOKING AT (but not too long...):

I'm no teacher, just a retired engineer who needed to consider resonance now and again. For folks that enjoy math, go to this site for a great introduction to old style resonance calculations. Believe it or not, engineers actually used to do this sort of thing with a pencil and paper. Some of us are so old that we remember when hand calculators came out! What an advance that was!

http://www.ncl.ac.uk/students/mathsaid/resources/academic/ode_resonance.htm

"(warning, there is some deep stuff there). If you want to do it an easier way just read on........

NOW ANYONE CAN INNOVATE AND INVENT THE EASY WAY!

That website was weird, beautiful, and yuk all at the same time. But the important thing is how our society has progressed. Spending years to do that kind of thinking is now optional.

It's no longer necessary to waste innovative energy.

Nifty and fun tho' those hand calculations can be, it is simply is not necessary to do things longhand anymore and also equally unnecessary to spend years learning math and physics. Now anyone and everyone can innovate. All it takes is a home computer, download a dynamic modeling program , spend an evening figuring how to work it, model something, and get to dreaming. The program will handle calculations and advise of errors. Innovation is what people do best anyway.

Roger L.

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----- Original Message -----

From: Julian Webb

To: electricboats@yahoogroups.com

Sent: Thursday, May 23, 2013 3:11 AM

Subject: Re: [Electric Boats] "Batteries Not Included"

SNIP...

- To cut a long story short unless the importance of electrical and mechanical resonance in systems is appreciated, (which has no place, constant or symbol in any traditional calculations or formulas that I have ever seen) they cannot be understood or replicated.