Yes indeed. I'm serious about not being able to accurately
mathematically model flow in a pipe. Just a plain old straight pipe.
Once the flow departs from pure laminar into turbulence it becomes
impossible to calculate. In real life experiments some components of
turbulent flow are moving backwards. If you think about it for just a
second that becomes obvious.
Lots of stuff can't be reliably modeled. Departure from nucleate
boiling to film boiling in a nuclear plant for instance. Endless work
on the supercomputers of the day--lots of Crays. In the end the
problem was deemed "intractable" which is expensive engineering lingo
for "beats the sh*t out of me". The final determination was "stay ten
percent under the critical heat flux for departure from nucleate
boiling". Hell, I could have told them that.
On Oct 22, 2008, at 7:31 PM, David Talbott wrote:
> This reminds me of a discussion with Benoit Mandelbrot on the
> NewsHour last
> night (in regard to rippling turbulence within the economy) during
> which he
> said:
>
> "The word "turbulence" is one which actually is common to physics
> and to
> social scientists, to economics. Everything which involves
> turbulence is
> enormously more complicated, not just a little bit more complicated,
> not
> just one year more schooling, just enormously more complicated."
>
> Mandelbrot, in addition to his mathematical fame (the "Father of
> Fractals"),
> originally studied aeronautical engineering and later worked in fluid
> dynamics, so if this cat still has trouble calculating turbulence,
> it's no
> wonder we haven't yet figured out how to model it on computers and
> we still
> need to mock it up to measure it.
>
> DT
>
> ----- Original Message ----- From: "Kas Kastner" <kaskas@cox.net>
> To: "Shane Ingate" <hottr6@hotmail.com>; "Friends of Triumph"
> <fot@autox.team.net>
> Sent: Wednesday, October 22, 2008 4:07 PM
> Subject: Re: [Fot] State of F1
>
>
>> We had all the computer people we needed plus our own hardware and
>> software
>> engineers at NPTI, and the modeling worked just fine for fit and
>> design
>> and
>> tooling but air is really different as we found in our wind tunnel.
>>
>> At that same time Williams F-1 sent all their stuff to a tunnel just
>> twenty
>> miles from us for proof that the modeling was correct. The tunnel
>> also
>> must
>> have a moving ground plane or it's no go. BMW has two full size
>> tunnels
>> and
>> for a good reason.
>>
>> ----- Original Message -----
>> From: Shane Ingate
>> To: Kas Kastner ; Friends of Triumph
>> Sent: Wednesday, October 22, 2008 3:16 PM
>> Subject: Re: [Fot] State of F1
>>
>>
>> Kas wrote:> Wind tunnels have an amazing cost. Some teams have two
>> full
>> size
>> running 24 > hours a day. That's interesting. I would have thought
>> that
>> today
>> all aerodynamic and structure-loading modeling was done on a
>> computer. As
>> Kas
>> suggests, wind tunnels are expensive, but computer modeling is dirt-
>> cheap
>> where an engineer can change model parameters and make the
>> calculations
>> within
>> minutes that would otherwise necessitate a complete day in a wind
>> tunnel.Many
>> models these days (I speak for hydrodynamic and sub-
>> atomicinteractions in
>> the
>> far-field) use non-linear models. I would not be surprised if non-
>> linear
>> models were used in the simple case of aerodynamics.Shane Ingate in
>> NM
>>
>> -----------------------------------------------------------------------------
>> -
>> You live life beyond your PC. So now Windows goes beyond your PC.
>> See how
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Bill Babcock
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